News for Your Practice

The author reports no financial relationships relevant to this article.

• Strategies that may help you avoid MVI
• Tips on how to recognize it
• What to do when MVI occurs

CASE Trocar insertion, then a bleed

Sophia, a 29-year-old nulliparous patient, undergoes diagnostic laparoscopy after unsuccessful medical therapy for chronic pelvic pain. After insufflation, a reusable 11-mm trocar with obturator is placed. A survey of the pelvis and abdomen reveals a 10-cm retroperitoneal hematoma in the midline just below the umbilicus.

What is the best way to manage this hemorrhage?

Contrary to widespread belief, gynecologic laparoscopy has a rate of major complication similar to, not higher than, that of laparotomy—but it has a higher rate of major vascular injury (MVI), defined as laceration of the aorta, inferior vena cava, or common iliac or external iliac vessels.¹ In fact, MVI appears to be somewhat exclusive to laparoscopy.

In a large review of 29,966 gynecologic laparoscopies, investigators found the surgeon’s level of experience to be an important variable in the overall complication rate but not in the incidence of MVI.² This means patients are at risk of MVI regardless of how many or how few laparoscopic procedures you perform.

What can a surgeon do to avert this type of injury? The most important strategy is to be conversant with variables that clearly increase the risk, as well as behaviors and protocols that can minimize it. This article offers five pearls—from prevention to postop management.

1. Pay attention to subtlety, starting at the preop visit

When a marriage counselor was asked which significant actions can improve a relationship, he responded: “The little things are the big things.”

To minimize the risk of vascular injury, a meticulous surgeon begins with the “little things” at the preoperative evaluation. Important considerations include the patient’s height, weight, and body mass index (BMI). Does she have a history of abdominal surgery or pelvic disease that could suggest intra-abdominal adhesions and anatomic distortion?

It is important to discuss the risk of bowel or vascular injury, as well as the need to convert to an open procedure, with all patients, but particularly with those who are thin or who have abnormal abdominal findings.

A recent randomized clinical trial found that routine mechanical bowel preparation did not facilitate surgery or decrease the incidence of complications, but may be helpful in select cases.³

2. Don’t undervalue that ounce of prevention

A commuter commented to her friend that she thought the bus driver had exceptional driving skill. The friend couldn’t understand this remark. “The driver hasn’t been challenged yet,” the friend argued. “She hasn’t needed to demonstrate any action in the face of an emergency—so how do you know what level of skill she has?”

“That is precisely the point,” the commuter replied. “The driver has exercised extreme judgment and caution so as not to require using her superior skill in an emergency.”

It is always better to avoid a potentially catastrophic complication than to manage it. The first requirement is vigilance in preparing for laparoscopy. It is important to ensure that the patient is in the supine position during initial entry and that her arms are comfortably tucked on both sides. In 85% of cases, the aorta can be palpated.⁴

Select an entry technique wisely

Base this decision on experience, patient characteristics, the surgical procedure, and availability of equipment. No entry technique or device can be considered completely safe.

Most vascular injuries occur during the initial phase of laparoscopy:

• As many as 39% are related to placement of the Veress needle
• As many as 37.9% are related to placement of the primary trocar.⁵

The classic “closed” method of laparoscopy has been used successfully for decades. In thin patients, insert the Veress needle toward the uterus. In computed tomography studies, an angle of at least 34 degrees has been shown to avoid the aorta and its bifurcation (FIGURE 1).⁶

The right common iliac vessel is most commonly involved in injury, given its anatomic relationship overriding the inferior vena cava (FIGURE 2). When you stand at the patient’s left, the Veress needle can inadvertently be directed off to the right of midline, in harm’s way of the right common iliac vessels.

FIGURE 1 In thin women, insert the Veress needle toward the uterus

If the angle of insertion is 45° (≥34°) in the sagittal plane at the umbilicus, puncture safely avoids the aortic bifurcation.

FIGURE 2 At risk: The right common iliac artery

The right common iliac artery overlies its corresponding vein, which puts the artery at risk of injury at initial insertion of the Veress needle.

Tips to facilitate entry

After insufflation, the distance from the base of the navel to the peritoneum is approximately 1.5 to 2.0 cm (FIGURE 3).⁷ It is neither necessary nor prudent to bury the needle to its hub when placing the initial trocar. Some authors report that over-inflation to 25 mm Hg lowers the risk of vascular injury, creating a longer distance to the retroperitoneal structures.⁸ In addition, the reduction of tenting means that less force is required.

Patients with a high BMI are likely to be protected from MVI, given the greater distances to major vessels.⁹ The distance between the entry trocar and retroperitoneal vessels increases directly with BMI, commensurate with increasing abdominal-wall thickness (FIGURE 4).

FIGURE 3 The umbilicus is at its thinnest at low body weight

The distance (cm) into the peritoneal cavity after insufflation correlates with a patient’s weight.
SOURCE: Milad and Terkildsen.⁷

FIGURE 4 How far is it from umbilical skin to the peritoneum and vascular structures?

SOURCE: Hurd et al.⁹

No single trocar is fail-safe

Even optical trocars have been associated with MVI. Between 1994 and 2002, 79 serious complications, including 37 MVIs, were associated with use of these trocars.¹⁰

Direct insertion, open technique, and optical trocars have not been studied in comparable numbers. Although the Hasson cannula was not associated with MVI in two large trials involving 10,840 and 5,284 procedures, respectively, there have been case reports to the contrary.^11-14

Rubinstein and colleagues¹⁵ evaluated the efficacy and safety of the radial dilating trocar VersaStep (US Surgical) for laparoscopic access. This trocar system has a blunt tip and circumferentially dilates rather than directly incising the fascia of the abdominal wall. Use of the blunt-tip trocar may decrease the incidence of initial access injury.

3. Don’t be the King or Queen of denial

Because MVI is estimated to occur in one in every 1,000 to one in every 10,000 procedures, and a typical gynecologic surgeon performs roughly 12 laparoscopies a year, it is unlikely that he or she will encounter more than one MVI over the course of a career. Nevertheless, when a retroperitoneal hematoma or brisk bleeding is visualized at laparoscopy, an MVI should immediately be suspected.

Do not enter into a state of denial and attempt to manage this complication conservatively. The earlier the MVI can be diagnosed, the better the outcome. A retroperitoneal hematoma, dark venous blood pooling in the abdomen, and bright red pulsatile blood are all signs of MVI. Do not wait for systemic changes such as hypotension or cardiac arrhythmias, as these are late findings.

4. No man is an island. Get help when you need it!

As residents, we had the shoulder-dystocia drill burned into memory, the first step being: “Call for help.” Regrettably, there is much less emphasis placed on the need to call for help in a surgical emergency.

All members of the surgical team should be notified of the situation and its associated gravity. The anesthesia team will need to ensure that there are adequate intravenous (IV) access, IV fluids, and blood products for resuscitation. The circulator will need to recruit help so that there will be additional hands to call consults, obtain blood, bring in abdominal trays, scrub in and retract, and so on.

5. Identify, secure, and control the site of injury

Just as a pilot must memorize the early response to an emergency, so must a surgeon be prepared for MVI. In the setting of potential catastrophic hemorrhage, time is of the essence.

The first task is to stay calm and avoid panic. Your role as the surgeon is to identify, secure, and control the site of injury while other team members work on their duties.

Laparoscopy usually not an option 2

It is the rare laparoscopic surgeon who can manage catastrophic hemorrhage endoscopically. It usually is best to remove the trocar from the vessel wall and convert to laparotomy. Attempting to leave a trocar in a vessel may extend the injury and create greater trauma to the vessel.

It is likely that patients will need to undergo secondary procedures if traditional laparoscopic interventions are used.

A vertical skin incision is best

The vertical incision is preferable because it allows greater access and visibility. Sadly, that information does not seem to translate into common practice. One study reported that 27 of 31 women with vascular injury were opened with a Pfannenstiel incision for emergency laparotomy.¹⁶

Control the bleeding

Apply pressure in an atraumatic fashion. Call for vascular instruments and a second suction device.

Control the bleeding digitally at first, followed by proximal and distal occlusion. Never use traumatic clamps because of the high rate of intimal damage associated with thrombi and secondary occlusion. Clips, staplers, or electrosurgery may cause vascular occlusion, thrombi, claudication, or lower-extremity edema.

Debride the blood and clots and identify the defect.

Repair the laceration

Polypropylene (6-0) can be used to close the defect in an interrupted fashion with sutures running parallel to the line of the vascular structure.

A vascular surgeon can be very helpful in the repair of vessels and should be consulted in the event of MVI. If extensive intimal damage has occurred, primary closure may not be possible and the vascular surgeon may perform a graft angioplasty repair or place a short interposition graft. Proximal and distal control is achieved by applying atraumatic clamps proximal and distal to the injury. Intravenous anticoagulation (5,000 U of heparin) is common but not mandatory. A longitudinal arteriotomy is extended, and any areas of thrombi are removed. The damaged intima is endarterectomized, and tacking sutures, using 7-0 Prolene, can be used to prevent propagation of the intimal dissection. Last, a venous or synthetic patch is sewn into place using 6-0 Prolene.

Patients typically remain on aspirin for 3 to 6 weeks.

CASE Resolved

Sophia’s procedure is immediately converted to a midline vertical laparotomy, a vascular surgery consult is obtained, and exploration reveals a 5-mm defect in the right common iliac artery consistent with an extended Veress needle injury. A vascular patch is used for the vessel repair, and the patient is discharged 4 days later in stable condition. She takes clopidogrel bisulfate (Plavix) for 6 weeks and has no lower-limb compromise.

The author reports no financial relationships relevant to this article.

• Strategies that may help you avoid MVI
• Tips on how to recognize it
• What to do when MVI occurs

CASE Trocar insertion, then a bleed

Sophia, a 29-year-old nulliparous patient, undergoes diagnostic laparoscopy after unsuccessful medical therapy for chronic pelvic pain. After insufflation, a reusable 11-mm trocar with obturator is placed. A survey of the pelvis and abdomen reveals a 10-cm retroperitoneal hematoma in the midline just below the umbilicus.

What is the best way to manage this hemorrhage?

Contrary to widespread belief, gynecologic laparoscopy has a rate of major complication similar to, not higher than, that of laparotomy—but it has a higher rate of major vascular injury (MVI), defined as laceration of the aorta, inferior vena cava, or common iliac or external iliac vessels.¹ In fact, MVI appears to be somewhat exclusive to laparoscopy.

In a large review of 29,966 gynecologic laparoscopies, investigators found the surgeon’s level of experience to be an important variable in the overall complication rate but not in the incidence of MVI.² This means patients are at risk of MVI regardless of how many or how few laparoscopic procedures you perform.

What can a surgeon do to avert this type of injury? The most important strategy is to be conversant with variables that clearly increase the risk, as well as behaviors and protocols that can minimize it. This article offers five pearls—from prevention to postop management.

1. Pay attention to subtlety, starting at the preop visit

When a marriage counselor was asked which significant actions can improve a relationship, he responded: “The little things are the big things.”

To minimize the risk of vascular injury, a meticulous surgeon begins with the “little things” at the preoperative evaluation. Important considerations include the patient’s height, weight, and body mass index (BMI). Does she have a history of abdominal surgery or pelvic disease that could suggest intra-abdominal adhesions and anatomic distortion?

It is important to discuss the risk of bowel or vascular injury, as well as the need to convert to an open procedure, with all patients, but particularly with those who are thin or who have abnormal abdominal findings.

A recent randomized clinical trial found that routine mechanical bowel preparation did not facilitate surgery or decrease the incidence of complications, but may be helpful in select cases.³

2. Don’t undervalue that ounce of prevention

A commuter commented to her friend that she thought the bus driver had exceptional driving skill. The friend couldn’t understand this remark. “The driver hasn’t been challenged yet,” the friend argued. “She hasn’t needed to demonstrate any action in the face of an emergency—so how do you know what level of skill she has?”

“That is precisely the point,” the commuter replied. “The driver has exercised extreme judgment and caution so as not to require using her superior skill in an emergency.”

It is always better to avoid a potentially catastrophic complication than to manage it. The first requirement is vigilance in preparing for laparoscopy. It is important to ensure that the patient is in the supine position during initial entry and that her arms are comfortably tucked on both sides. In 85% of cases, the aorta can be palpated.⁴

Select an entry technique wisely

Base this decision on experience, patient characteristics, the surgical procedure, and availability of equipment. No entry technique or device can be considered completely safe.

Most vascular injuries occur during the initial phase of laparoscopy:

• As many as 39% are related to placement of the Veress needle
• As many as 37.9% are related to placement of the primary trocar.⁵

The classic “closed” method of laparoscopy has been used successfully for decades. In thin patients, insert the Veress needle toward the uterus. In computed tomography studies, an angle of at least 34 degrees has been shown to avoid the aorta and its bifurcation (FIGURE 1).⁶

The right common iliac vessel is most commonly involved in injury, given its anatomic relationship overriding the inferior vena cava (FIGURE 2). When you stand at the patient’s left, the Veress needle can inadvertently be directed off to the right of midline, in harm’s way of the right common iliac vessels.

FIGURE 1 In thin women, insert the Veress needle toward the uterus

If the angle of insertion is 45° (≥34°) in the sagittal plane at the umbilicus, puncture safely avoids the aortic bifurcation.

FIGURE 2 At risk: The right common iliac artery

The right common iliac artery overlies its corresponding vein, which puts the artery at risk of injury at initial insertion of the Veress needle.

Tips to facilitate entry

After insufflation, the distance from the base of the navel to the peritoneum is approximately 1.5 to 2.0 cm (FIGURE 3).⁷ It is neither necessary nor prudent to bury the needle to its hub when placing the initial trocar. Some authors report that over-inflation to 25 mm Hg lowers the risk of vascular injury, creating a longer distance to the retroperitoneal structures.⁸ In addition, the reduction of tenting means that less force is required.

Patients with a high BMI are likely to be protected from MVI, given the greater distances to major vessels.⁹ The distance between the entry trocar and retroperitoneal vessels increases directly with BMI, commensurate with increasing abdominal-wall thickness (FIGURE 4).

FIGURE 3 The umbilicus is at its thinnest at low body weight

The distance (cm) into the peritoneal cavity after insufflation correlates with a patient’s weight.
SOURCE: Milad and Terkildsen.⁷

FIGURE 4 How far is it from umbilical skin to the peritoneum and vascular structures?

SOURCE: Hurd et al.⁹

No single trocar is fail-safe

Even optical trocars have been associated with MVI. Between 1994 and 2002, 79 serious complications, including 37 MVIs, were associated with use of these trocars.¹⁰

Direct insertion, open technique, and optical trocars have not been studied in comparable numbers. Although the Hasson cannula was not associated with MVI in two large trials involving 10,840 and 5,284 procedures, respectively, there have been case reports to the contrary.^11-14

Rubinstein and colleagues¹⁵ evaluated the efficacy and safety of the radial dilating trocar VersaStep (US Surgical) for laparoscopic access. This trocar system has a blunt tip and circumferentially dilates rather than directly incising the fascia of the abdominal wall. Use of the blunt-tip trocar may decrease the incidence of initial access injury.

3. Don’t be the King or Queen of denial

Because MVI is estimated to occur in one in every 1,000 to one in every 10,000 procedures, and a typical gynecologic surgeon performs roughly 12 laparoscopies a year, it is unlikely that he or she will encounter more than one MVI over the course of a career. Nevertheless, when a retroperitoneal hematoma or brisk bleeding is visualized at laparoscopy, an MVI should immediately be suspected.

Do not enter into a state of denial and attempt to manage this complication conservatively. The earlier the MVI can be diagnosed, the better the outcome. A retroperitoneal hematoma, dark venous blood pooling in the abdomen, and bright red pulsatile blood are all signs of MVI. Do not wait for systemic changes such as hypotension or cardiac arrhythmias, as these are late findings.

4. No man is an island. Get help when you need it!

As residents, we had the shoulder-dystocia drill burned into memory, the first step being: “Call for help.” Regrettably, there is much less emphasis placed on the need to call for help in a surgical emergency.

All members of the surgical team should be notified of the situation and its associated gravity. The anesthesia team will need to ensure that there are adequate intravenous (IV) access, IV fluids, and blood products for resuscitation. The circulator will need to recruit help so that there will be additional hands to call consults, obtain blood, bring in abdominal trays, scrub in and retract, and so on.

5. Identify, secure, and control the site of injury

Just as a pilot must memorize the early response to an emergency, so must a surgeon be prepared for MVI. In the setting of potential catastrophic hemorrhage, time is of the essence.

The first task is to stay calm and avoid panic. Your role as the surgeon is to identify, secure, and control the site of injury while other team members work on their duties.

Laparoscopy usually not an option 2

It is the rare laparoscopic surgeon who can manage catastrophic hemorrhage endoscopically. It usually is best to remove the trocar from the vessel wall and convert to laparotomy. Attempting to leave a trocar in a vessel may extend the injury and create greater trauma to the vessel.

It is likely that patients will need to undergo secondary procedures if traditional laparoscopic interventions are used.

A vertical skin incision is best

The vertical incision is preferable because it allows greater access and visibility. Sadly, that information does not seem to translate into common practice. One study reported that 27 of 31 women with vascular injury were opened with a Pfannenstiel incision for emergency laparotomy.¹⁶

Control the bleeding

Apply pressure in an atraumatic fashion. Call for vascular instruments and a second suction device.

Control the bleeding digitally at first, followed by proximal and distal occlusion. Never use traumatic clamps because of the high rate of intimal damage associated with thrombi and secondary occlusion. Clips, staplers, or electrosurgery may cause vascular occlusion, thrombi, claudication, or lower-extremity edema.

Debride the blood and clots and identify the defect.

Repair the laceration

Polypropylene (6-0) can be used to close the defect in an interrupted fashion with sutures running parallel to the line of the vascular structure.

A vascular surgeon can be very helpful in the repair of vessels and should be consulted in the event of MVI. If extensive intimal damage has occurred, primary closure may not be possible and the vascular surgeon may perform a graft angioplasty repair or place a short interposition graft. Proximal and distal control is achieved by applying atraumatic clamps proximal and distal to the injury. Intravenous anticoagulation (5,000 U of heparin) is common but not mandatory. A longitudinal arteriotomy is extended, and any areas of thrombi are removed. The damaged intima is endarterectomized, and tacking sutures, using 7-0 Prolene, can be used to prevent propagation of the intimal dissection. Last, a venous or synthetic patch is sewn into place using 6-0 Prolene.

Patients typically remain on aspirin for 3 to 6 weeks.

CASE Resolved

Sophia’s procedure is immediately converted to a midline vertical laparotomy, a vascular surgery consult is obtained, and exploration reveals a 5-mm defect in the right common iliac artery consistent with an extended Veress needle injury. A vascular patch is used for the vessel repair, and the patient is discharged 4 days later in stable condition. She takes clopidogrel bisulfate (Plavix) for 6 weeks and has no lower-limb compromise.

The author reports no financial relationships relevant to this article.

• Strategies that may help you avoid MVI
• Tips on how to recognize it
• What to do when MVI occurs

CASE Trocar insertion, then a bleed

Sophia, a 29-year-old nulliparous patient, undergoes diagnostic laparoscopy after unsuccessful medical therapy for chronic pelvic pain. After insufflation, a reusable 11-mm trocar with obturator is placed. A survey of the pelvis and abdomen reveals a 10-cm retroperitoneal hematoma in the midline just below the umbilicus.

What is the best way to manage this hemorrhage?

Contrary to widespread belief, gynecologic laparoscopy has a rate of major complication similar to, not higher than, that of laparotomy—but it has a higher rate of major vascular injury (MVI), defined as laceration of the aorta, inferior vena cava, or common iliac or external iliac vessels.¹ In fact, MVI appears to be somewhat exclusive to laparoscopy.

In a large review of 29,966 gynecologic laparoscopies, investigators found the surgeon’s level of experience to be an important variable in the overall complication rate but not in the incidence of MVI.² This means patients are at risk of MVI regardless of how many or how few laparoscopic procedures you perform.

What can a surgeon do to avert this type of injury? The most important strategy is to be conversant with variables that clearly increase the risk, as well as behaviors and protocols that can minimize it. This article offers five pearls—from prevention to postop management.

1. Pay attention to subtlety, starting at the preop visit

When a marriage counselor was asked which significant actions can improve a relationship, he responded: “The little things are the big things.”

To minimize the risk of vascular injury, a meticulous surgeon begins with the “little things” at the preoperative evaluation. Important considerations include the patient’s height, weight, and body mass index (BMI). Does she have a history of abdominal surgery or pelvic disease that could suggest intra-abdominal adhesions and anatomic distortion?

It is important to discuss the risk of bowel or vascular injury, as well as the need to convert to an open procedure, with all patients, but particularly with those who are thin or who have abnormal abdominal findings.

A recent randomized clinical trial found that routine mechanical bowel preparation did not facilitate surgery or decrease the incidence of complications, but may be helpful in select cases.³

2. Don’t undervalue that ounce of prevention

A commuter commented to her friend that she thought the bus driver had exceptional driving skill. The friend couldn’t understand this remark. “The driver hasn’t been challenged yet,” the friend argued. “She hasn’t needed to demonstrate any action in the face of an emergency—so how do you know what level of skill she has?”

“That is precisely the point,” the commuter replied. “The driver has exercised extreme judgment and caution so as not to require using her superior skill in an emergency.”

It is always better to avoid a potentially catastrophic complication than to manage it. The first requirement is vigilance in preparing for laparoscopy. It is important to ensure that the patient is in the supine position during initial entry and that her arms are comfortably tucked on both sides. In 85% of cases, the aorta can be palpated.⁴

Select an entry technique wisely

Base this decision on experience, patient characteristics, the surgical procedure, and availability of equipment. No entry technique or device can be considered completely safe.

Most vascular injuries occur during the initial phase of laparoscopy:

• As many as 39% are related to placement of the Veress needle
• As many as 37.9% are related to placement of the primary trocar.⁵

The classic “closed” method of laparoscopy has been used successfully for decades. In thin patients, insert the Veress needle toward the uterus. In computed tomography studies, an angle of at least 34 degrees has been shown to avoid the aorta and its bifurcation (FIGURE 1).⁶

The right common iliac vessel is most commonly involved in injury, given its anatomic relationship overriding the inferior vena cava (FIGURE 2). When you stand at the patient’s left, the Veress needle can inadvertently be directed off to the right of midline, in harm’s way of the right common iliac vessels.

FIGURE 1 In thin women, insert the Veress needle toward the uterus

If the angle of insertion is 45° (≥34°) in the sagittal plane at the umbilicus, puncture safely avoids the aortic bifurcation.

FIGURE 2 At risk: The right common iliac artery

The right common iliac artery overlies its corresponding vein, which puts the artery at risk of injury at initial insertion of the Veress needle.

Tips to facilitate entry

After insufflation, the distance from the base of the navel to the peritoneum is approximately 1.5 to 2.0 cm (FIGURE 3).⁷ It is neither necessary nor prudent to bury the needle to its hub when placing the initial trocar. Some authors report that over-inflation to 25 mm Hg lowers the risk of vascular injury, creating a longer distance to the retroperitoneal structures.⁸ In addition, the reduction of tenting means that less force is required.

Patients with a high BMI are likely to be protected from MVI, given the greater distances to major vessels.⁹ The distance between the entry trocar and retroperitoneal vessels increases directly with BMI, commensurate with increasing abdominal-wall thickness (FIGURE 4).

FIGURE 3 The umbilicus is at its thinnest at low body weight

The distance (cm) into the peritoneal cavity after insufflation correlates with a patient’s weight.
SOURCE: Milad and Terkildsen.⁷

FIGURE 4 How far is it from umbilical skin to the peritoneum and vascular structures?

SOURCE: Hurd et al.⁹

No single trocar is fail-safe

Even optical trocars have been associated with MVI. Between 1994 and 2002, 79 serious complications, including 37 MVIs, were associated with use of these trocars.¹⁰

Direct insertion, open technique, and optical trocars have not been studied in comparable numbers. Although the Hasson cannula was not associated with MVI in two large trials involving 10,840 and 5,284 procedures, respectively, there have been case reports to the contrary.^11-14

Rubinstein and colleagues¹⁵ evaluated the efficacy and safety of the radial dilating trocar VersaStep (US Surgical) for laparoscopic access. This trocar system has a blunt tip and circumferentially dilates rather than directly incising the fascia of the abdominal wall. Use of the blunt-tip trocar may decrease the incidence of initial access injury.

3. Don’t be the King or Queen of denial

Because MVI is estimated to occur in one in every 1,000 to one in every 10,000 procedures, and a typical gynecologic surgeon performs roughly 12 laparoscopies a year, it is unlikely that he or she will encounter more than one MVI over the course of a career. Nevertheless, when a retroperitoneal hematoma or brisk bleeding is visualized at laparoscopy, an MVI should immediately be suspected.

Do not enter into a state of denial and attempt to manage this complication conservatively. The earlier the MVI can be diagnosed, the better the outcome. A retroperitoneal hematoma, dark venous blood pooling in the abdomen, and bright red pulsatile blood are all signs of MVI. Do not wait for systemic changes such as hypotension or cardiac arrhythmias, as these are late findings.

4. No man is an island. Get help when you need it!

As residents, we had the shoulder-dystocia drill burned into memory, the first step being: “Call for help.” Regrettably, there is much less emphasis placed on the need to call for help in a surgical emergency.

All members of the surgical team should be notified of the situation and its associated gravity. The anesthesia team will need to ensure that there are adequate intravenous (IV) access, IV fluids, and blood products for resuscitation. The circulator will need to recruit help so that there will be additional hands to call consults, obtain blood, bring in abdominal trays, scrub in and retract, and so on.

5. Identify, secure, and control the site of injury

Just as a pilot must memorize the early response to an emergency, so must a surgeon be prepared for MVI. In the setting of potential catastrophic hemorrhage, time is of the essence.

The first task is to stay calm and avoid panic. Your role as the surgeon is to identify, secure, and control the site of injury while other team members work on their duties.

Laparoscopy usually not an option 2

It is the rare laparoscopic surgeon who can manage catastrophic hemorrhage endoscopically. It usually is best to remove the trocar from the vessel wall and convert to laparotomy. Attempting to leave a trocar in a vessel may extend the injury and create greater trauma to the vessel.

It is likely that patients will need to undergo secondary procedures if traditional laparoscopic interventions are used.

A vertical skin incision is best

The vertical incision is preferable because it allows greater access and visibility. Sadly, that information does not seem to translate into common practice. One study reported that 27 of 31 women with vascular injury were opened with a Pfannenstiel incision for emergency laparotomy.¹⁶

Control the bleeding

Apply pressure in an atraumatic fashion. Call for vascular instruments and a second suction device.

Control the bleeding digitally at first, followed by proximal and distal occlusion. Never use traumatic clamps because of the high rate of intimal damage associated with thrombi and secondary occlusion. Clips, staplers, or electrosurgery may cause vascular occlusion, thrombi, claudication, or lower-extremity edema.

Debride the blood and clots and identify the defect.

Repair the laceration

Polypropylene (6-0) can be used to close the defect in an interrupted fashion with sutures running parallel to the line of the vascular structure.

A vascular surgeon can be very helpful in the repair of vessels and should be consulted in the event of MVI. If extensive intimal damage has occurred, primary closure may not be possible and the vascular surgeon may perform a graft angioplasty repair or place a short interposition graft. Proximal and distal control is achieved by applying atraumatic clamps proximal and distal to the injury. Intravenous anticoagulation (5,000 U of heparin) is common but not mandatory. A longitudinal arteriotomy is extended, and any areas of thrombi are removed. The damaged intima is endarterectomized, and tacking sutures, using 7-0 Prolene, can be used to prevent propagation of the intimal dissection. Last, a venous or synthetic patch is sewn into place using 6-0 Prolene.

Patients typically remain on aspirin for 3 to 6 weeks.

CASE Resolved

Sophia’s procedure is immediately converted to a midline vertical laparotomy, a vascular surgery consult is obtained, and exploration reveals a 5-mm defect in the right common iliac artery consistent with an extended Veress needle injury. A vascular patch is used for the vessel repair, and the patient is discharged 4 days later in stable condition. She takes clopidogrel bisulfate (Plavix) for 6 weeks and has no lower-limb compromise.

The author reports no financial relationships relevant to this article.

CASE 1 Fluid-filled abdominal mass

A 14-year-old girl complains of crampy, episodic, lower abdominal pain of 3 months’ duration and acute retention of urine. She also reports back pain and dyschezia. She has never menstruated, but her breasts began developing 18 months earlier. Examination reveals normal Tanner stage 3 breast development and female hair distribution and a large abdominal mass. No fetal heart tones are apparent. The external genitalia appear to be normal except for a bulging mass at the introitus.

Imaging (FIGURE 1) reveals that the mass is fluid-filled. The uterus, tubes, and ovaries are present at the dome of the mass. The kidneys are normal.

What is the mass?

FIGURE 1 No exit for menstrual products

An MRI shows a large hematocolpos that develops after menarche in women who have outflow obstruction, such as imperforate hymen—as this patient had.A list of the processes involved in normal development of the female reproductive tract highlights its precarious complexity: cellular differentiation, migration, canalization, fusion, and programmed cell death. A failure in any of these processes can cause a malformation. When that malformation becomes apparent depends on the stage of life of the patient and the nature of the abnormality. As you might imagine, diagnosis and treatment are not always straightforward.

In the patient just described, the likely diagnosis is imperforate hymen or transverse vaginal septum due to failed canalization of the vaginal plate. The patient has been menstruating internally for many months and now has a large hematocolpos. Urinary retention develops when the amount of retained blood in the vagina causes acute angulation of the urethrovesical junction. Evacuation of the blood restores the physiologic angle, enabling the patient to void normally.

Most anomalies involving the external genitalia are apparent at birth (clitoromegaly, imperforate hymen), whereas obstructive and nonobstructive malformations may become evident at birth; during childhood, puberty, or adolescence; or with menarche or childbearing.

Treatment of these abnormalities has changed significantly over the past few years—largely due to refinements in diagnostic imaging, surgical and nonsurgical techniques, and instrumentation. These advances have improved reproductive function and enhanced the psychosexual attitude of these patients.

In this article, I review the most common abnormalities and describe their evaluation and management.

Just what is normal development?

Vaginal canalization

The sinovaginal bulbs are two solid evaginations originating from the urogenital sinus at the distal aspect of the müllerian tubercle, as shown at right (A). The sinovaginal bulbs proliferate into the caudal end of the uterovaginal canal to become the solid vaginal plate (B). The lumen of the lower vagina is formed by degeneration of the central cells of this vaginal plate, which occurs in a cephalad direction (C). This process of canalization is complete by 20 weeks’ gestation.

Hymen usually ruptures before birth

The vaginal hymen is separated from the urogenital sinus by the hymeneal membrane. The hymen usually ruptures before birth with the degeneration of central epithelial cells (i.e., canalization), leaving a thin fold of mucous membrane around the vaginal introitus.

Uterus, fallopian tubes develop from solid tissue

The müllerian ducts are first identifiable at approximately 6 weeks of gestation, when they begin to elongate caudally and cross the metanephric ducts medially to meet in the midline. By the seventh week, the urorectal septum has developed, separating the rectum from the urogenital sinus. Around 12 weeks’ gestation, the caudal portion of the müllerian ducts fuses to form the uterovaginal canal, which inserts into the dorsal wall of the urogenital sinus at Müller’s tubercle.

The two müllerian ducts are initially solid tissue and lie side by side. Subsequently, internal canalization of each duct produces two channels divided by a septum that is reabsorbed in a cephalad direction by 20 weeks. The cranial unfused portions of the müllerian ducts develop into the fimbria and fallopian tubes, whereas the caudal, fused portions form the uterus and upper vagina.

Impaired canalization

Imperforate hymen

The most common obstructive lesion of the female reproductive tract is an imperforate hymen. It can be diagnosed at birth with careful examination to ensure patency of both the rectum and vagina. Not infrequently, the infant presents with a bulging introitus due to mucocolpos from vaginal secretions stimulated by maternal estrogen (FIGURE 2). If diagnosis is delayed, the mucus usually resorbs and the child remains asymptomatic until menarche, when she presents with a bulging hymen and a large hematocolpos, as in the opening case. Management of imperforate hymen is feasible for the generalist. Repair can be performed in a patient of any age, but is facilitated if the tissue has undergone estrogen stimulation. Surgery is, therefore, ideal in the neonatal, postpubertal, and premenarchal periods.

Repair involves incision of the membrane near the hymeneal ring, followed by evacuation of accumulated blood. The cervix may appear to be flush with the vaginal apex, owing to compression, but this condition usually corrects itself within 2 or 3 weeks. Extra hymeneal tissue is excised to create an orifice of normal size, and the vaginal mucosa is intermittently sutured to the hymeneal ring using absorbable material (FIGURE 3).

FIGURE 2 Imperforate hymen

Bulging hymen due to mucocolpos in a newborn (top) and hematocolpos in an adolescent (bottom).

FIGURE 3 Hymenectomy restores vaginal orifice

Extra hymeneal tissue is excised to create an orifice of normal size. The vaginal mucosa is intermittently sutured to the hymeneal ring.

Incomplete hymeneal fenestration

This condition often goes undiagnosed until the patient seeks evaluation for an inability to insert tampons or medication or because of coital difficulty. Young girls with microperforate hymen may present with postmenstrual spotting or malodorous discharge due to partial obstruction and poor drainage.

Treatment of microperforate, cribriform, or septate hymen entails resection of excess hymeneal tissue to create a functional hymeneal ring.

Transverse vaginal septum

A transverse septum represents failed canalization of the vaginal plate. This condition occurs in approximately one of every 18,000 to 30,000 women.^1,2 The septum can be located at any of various levels in the vagina; approximately 46% are found in the upper vagina, 35% to 40% in the middle portion, and 15% to 20% in the lower vagina.^1,2 Lower septa appear to be thinner than those in the proximal vagina; thinness may be due to the pressure of accumulated fluid. If a small perforation is present, the patient will experience irregular spotting.

Examination. The external genitalia appear to be normal, but the vagina is shortened. Children may present with mucocolpos, whereas adolescents develop hematocolpos. If a small perforation is present, pyohematocolpos may result from ascending infection. A mass can be palpated on rectal examination.

Ultrasonography (US) or magnetic resonance imaging (MRI) helps define the location and thickness of the septum and distinguish a high septum from congenital absence of the cervix.

Treatment. Resect a small septum and perform end-to-end anastomosis of the upper and lower edges of the vaginal wall (FIGURE 4). Only an experienced surgeon should excise a thick septum. Reanastomosis is easier if the upper vagina is distended with menstrual blood. To ensure healing without stricture, mobilize the vaginal edge circumferentially before suturing the raw edges.

Outflow obstruction caused by a transverse septum in the distal vagina almost never leads to hematometra or hematosalpinx. However, septa that arise in the proximal vagina are usually thicker and, if left untreated, can cause reflux that damages the upper reproductive tract. These cases are almost always associated with severe dysmenorrhea and should be referred to an experienced vaginal surgeon. Pelvic MRI is recommended to assess the thickness and precise anatomy of the defect before repair.

FIGURE 4 Removing a transverse vaginal septum

The septum is resected from the distal vagina. This is followed by end-to-end anastomosis of mucosal edges.

Uterine septum

A septate uterus has a normal external surface but two endometrial cavities. It is caused by a defect in fusion or resorption of the midline septum between the two müllerian ducts. The degree of septation varies from a small midline septum to a total failure of resorption that produces a septate uterus with a longitudinal vaginal septum. A slight midline septum with minimal fundal indentation is classified by some as a septate uterus; by others, as a bicornuate uterus.

A higher risk of recurrent miscarriage is associated with longer septa.

Surgical repair with hysteroscopic resection of the septum yields excellent results.

CASE 2 The problem of agenesis

An 18-year-old patient consults a gynecologist because she has never menstruated and is unable to have sexual intercourse. She appears to be phenotypically normal, with normal labia upon examination, but no hymeneal opening is found. Pelvic US reveals absence of the uterus with ovaries that appear to be normal.

How should her condition be managed?

Uterovaginal agenesis, also known as müllerian aplasia or Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome, refers to congenital absence of the vagina with variable uterine development (FIGURE 5). It arises from agenesis of the

müllerian duct system, although the underlying cause is unknown. Vaginal agenesis is usually accompanied by cervical and uterine agenesis. However, 7% to 12% of patients with this syndrome have a normal but obstructed or rudimentary uterus with functional endometrium. This condition occurs in roughly one of every 5,000 females.^1,3

In addition, these girls often exhibit extragenital anomalies.^1,4 Approximately 25% to 50% have a urologic anomaly, such as unilateral renal agenesis, pelvic or horseshoe kidneys, or irregularities of the collecting systems; 10% to 15% have another type of anomaly, such as congenital heart disease, abnormalities of the hands, congenital deafness, cleft palate, and inguinal or femoral hernia.

The genetic basis of MRKH syndrome is unknown. These patients have normal female karyotypes and phenotypes with normal ovaries and ovarian function—although there is evidence that they are prone to early menopause. They develop secondary sexual characteristics. They usually present with primary amenorrhea at 15 to 17 years of age.

Vaginal agenesis is the second most common cause of primary amenorrhea after gonadal dysgenesis. Most patients have a rudimentary, nonfunctioning uterus, but 2% to 7% have a uterus with functioning endometrium and present with cyclic or chronic abdominopelvic pain secondary to obstruction or endometriosis, hematocolpos, or hematometra.

Imaging. US examination facilitates evaluation of the kidneys and confirms the presence of ovaries and absence of the uterus. MRI may be useful to confirm the presence of functioning endometrium.

The differential diagnosis of vaginal agenesis includes androgen insensitivity and low-lying transverse vaginal septum. Treatment includes psychosocial support to reassure the patient that a normal sex life will be possible after treatment.⁵ Construction of a neovagina, using vaginal dilators (the first-line strategy) or surgical placement of split-thickness skin graft or artificial skin (Abbe–McIndoe procedure), is the treatment. In one case series, more than 90% of patients with vaginal agenesis were successfully treated using vaginal dilation.⁶

The American College of Obstetricians and Gynecologists (ACOG) recommends that patients be referred to centers with expertise in surgical creation of a neovagina.⁵

FIGURE 5 Uterine agenesis

This depiction of uterine agenesis shows small, nonfunctioning müllerian remnants and normal tubes and ovaries.

Agenesis of the lower vagina

This malformation is caused by a failure of canalization of the sinovaginal bulbs and vaginal plate. The tubes, ovaries, cervix, and upper vagina are normal, but the lower vagina is replaced by fibrous tissue. Adolescents present with primary amenorrhea accompanied by cyclic pelvic pain. A vaginal dimple may be apparent on external inspection.

Because these girls have normal cyclic pituitary–ovarian–endometrial function at menarche, the upper vagina will distend with blood and secretions, and a mass can be palpated on rectoabdominal examination. US confirms the presence of a fluid-filled mass, and MRI further defines the length of obstruction.

Treatment. Surgery (by an experienced vaginal surgeon) is best performed when a large hematocolpos is present because distention increases the amount of tissue available for pull-through.

CASE 3 Fusion failure

A 17-year-old woman complains of lower abdominal pain and an enlarging abdomen. Menarche occurred at 13 years. The patient began to notice right-sided lower abdominal pain and abdominal swelling about 2 years ago, but denies any other symptoms.

Examination reveals a mass arising from the right lateral vaginal wall. The cervix appears to be normal. US shows a large, predominantly right-sided, fluid-filled mass arising from the pelvis. The uterus appears to be didelphic, with normal ovaries and an absent right kidney.

What is the mass?

This is a classic description of uterovaginal duplication that arises when the müllerian ducts fail to fuse (FIGURE 6).

In this case, the right-sided vagina failed to canalize as well, causing a large hematocolpos. Generally, duplication is limited to the uterus and cervix (uterus didelphys bicollis), although duplication of the vulva, bladder, urethra, vagina, and anus have been described.

Women with a didelphic uterus often have a good reproductive outcome. A septated vagina occurs in 75% of cases and may cause difficulty with sexual intercourse or vaginal delivery. Symptomatic women usually opt for resection of the vaginal septum.

Women who have an obstructed hemivagina and ipsilateral renal agenesis have regular menses because menstrual blood from one uterus can exit through its unobstructed side.

Treatment involves resection of the wall of the obstructed vagina, creating a single vaginal vault. If both vaginas have failed to canalize, the patient will present much earlier, with primary amenorrhea and cyclic pelvic pain—a presentation similar to that of transverse septum. Reconstructive surgery of the uterus is not recommended for complete duplication of the uterus.^1,7

FIGURE 6 Uterus didelphys

This patient has uterus didelphys with an obstructed hemivagina.

Unicornuate and bicornuate uterus

A unicornuate uterus represents an asymmetric lateral fusion defect. One cavity is usually normal, with a fallopian tube and cervix, but the failed müllerian duct can have various configurations. The affected müllerian duct may fail to develop, or it may develop partially as a horn on the uterus or a separate structure that may or may not communicate with the uterus.

Most rudimentary horns are asymptomatic, but others contain functional endometrium that is shed cyclically. If the rudimentary horn is obstructed, as is usually the case, the woman develops cyclic or chronic abdominopelvic pain that necessitates surgical excision of the horn. Endometriosis, a result of reflux, is common.

In a bicornuate uterus, the fundus is indented and the vagina is normal. This anomaly occurs when the müllerian ducts fuse only partially. The result is varying degrees of separation of the uterine horns.

Pregnancy outcomes appear to be similar to those of the general population. However, some women develop early pregnancy loss, preterm labor, incompetent cervix, or malpresentation.

Treatment is open surgical reunification.

CASE 4 Embryonic rest cells

A 55-year-old woman complains of “fullness” in the vagina, especially during intercourse. Upon examination, a 4- to 5-cm fluid-filled cyst is visible at the right posterior fornix.

What type of cyst is it?

Gartner’s duct cysts from embryonic rest cells arise from remnants of the metanephric duct system. They usually develop on the lateral vaginal walls or fornix (FIGURE 7), unlike epidermal inclusion cysts, which are generally located on the posterior wall or at the cervical–vesical junction. Although they sometimes cause dyspareunia or make it difficult for the patient to insert a tampon, they are usually asymptomatic unless they are large. Intervention is not indicated unless the patient is symptomatic.

Treatment. Marsupialization rather than excision is the treatment of choice because these embryonic rest cells may extend deep into the retroperitoneum.

FIGURE 7 Gartner’s duct cysts

These bilateral cysts developed from embryonic rest cells.

The author reports no financial relationships relevant to this article.

CASE 1 Fluid-filled abdominal mass

A 14-year-old girl complains of crampy, episodic, lower abdominal pain of 3 months’ duration and acute retention of urine. She also reports back pain and dyschezia. She has never menstruated, but her breasts began developing 18 months earlier. Examination reveals normal Tanner stage 3 breast development and female hair distribution and a large abdominal mass. No fetal heart tones are apparent. The external genitalia appear to be normal except for a bulging mass at the introitus.

Imaging (FIGURE 1) reveals that the mass is fluid-filled. The uterus, tubes, and ovaries are present at the dome of the mass. The kidneys are normal.

What is the mass?

FIGURE 1 No exit for menstrual products

An MRI shows a large hematocolpos that develops after menarche in women who have outflow obstruction, such as imperforate hymen—as this patient had.A list of the processes involved in normal development of the female reproductive tract highlights its precarious complexity: cellular differentiation, migration, canalization, fusion, and programmed cell death. A failure in any of these processes can cause a malformation. When that malformation becomes apparent depends on the stage of life of the patient and the nature of the abnormality. As you might imagine, diagnosis and treatment are not always straightforward.

In the patient just described, the likely diagnosis is imperforate hymen or transverse vaginal septum due to failed canalization of the vaginal plate. The patient has been menstruating internally for many months and now has a large hematocolpos. Urinary retention develops when the amount of retained blood in the vagina causes acute angulation of the urethrovesical junction. Evacuation of the blood restores the physiologic angle, enabling the patient to void normally.

Most anomalies involving the external genitalia are apparent at birth (clitoromegaly, imperforate hymen), whereas obstructive and nonobstructive malformations may become evident at birth; during childhood, puberty, or adolescence; or with menarche or childbearing.

Treatment of these abnormalities has changed significantly over the past few years—largely due to refinements in diagnostic imaging, surgical and nonsurgical techniques, and instrumentation. These advances have improved reproductive function and enhanced the psychosexual attitude of these patients.

In this article, I review the most common abnormalities and describe their evaluation and management.

Just what is normal development?

Vaginal canalization

The sinovaginal bulbs are two solid evaginations originating from the urogenital sinus at the distal aspect of the müllerian tubercle, as shown at right (A). The sinovaginal bulbs proliferate into the caudal end of the uterovaginal canal to become the solid vaginal plate (B). The lumen of the lower vagina is formed by degeneration of the central cells of this vaginal plate, which occurs in a cephalad direction (C). This process of canalization is complete by 20 weeks’ gestation.

Hymen usually ruptures before birth

The vaginal hymen is separated from the urogenital sinus by the hymeneal membrane. The hymen usually ruptures before birth with the degeneration of central epithelial cells (i.e., canalization), leaving a thin fold of mucous membrane around the vaginal introitus.

Uterus, fallopian tubes develop from solid tissue

The müllerian ducts are first identifiable at approximately 6 weeks of gestation, when they begin to elongate caudally and cross the metanephric ducts medially to meet in the midline. By the seventh week, the urorectal septum has developed, separating the rectum from the urogenital sinus. Around 12 weeks’ gestation, the caudal portion of the müllerian ducts fuses to form the uterovaginal canal, which inserts into the dorsal wall of the urogenital sinus at Müller’s tubercle.

The two müllerian ducts are initially solid tissue and lie side by side. Subsequently, internal canalization of each duct produces two channels divided by a septum that is reabsorbed in a cephalad direction by 20 weeks. The cranial unfused portions of the müllerian ducts develop into the fimbria and fallopian tubes, whereas the caudal, fused portions form the uterus and upper vagina.

Impaired canalization

Imperforate hymen

The most common obstructive lesion of the female reproductive tract is an imperforate hymen. It can be diagnosed at birth with careful examination to ensure patency of both the rectum and vagina. Not infrequently, the infant presents with a bulging introitus due to mucocolpos from vaginal secretions stimulated by maternal estrogen (FIGURE 2). If diagnosis is delayed, the mucus usually resorbs and the child remains asymptomatic until menarche, when she presents with a bulging hymen and a large hematocolpos, as in the opening case. Management of imperforate hymen is feasible for the generalist. Repair can be performed in a patient of any age, but is facilitated if the tissue has undergone estrogen stimulation. Surgery is, therefore, ideal in the neonatal, postpubertal, and premenarchal periods.

Repair involves incision of the membrane near the hymeneal ring, followed by evacuation of accumulated blood. The cervix may appear to be flush with the vaginal apex, owing to compression, but this condition usually corrects itself within 2 or 3 weeks. Extra hymeneal tissue is excised to create an orifice of normal size, and the vaginal mucosa is intermittently sutured to the hymeneal ring using absorbable material (FIGURE 3).

FIGURE 2 Imperforate hymen

Bulging hymen due to mucocolpos in a newborn (top) and hematocolpos in an adolescent (bottom).

FIGURE 3 Hymenectomy restores vaginal orifice

Extra hymeneal tissue is excised to create an orifice of normal size. The vaginal mucosa is intermittently sutured to the hymeneal ring.

Incomplete hymeneal fenestration

This condition often goes undiagnosed until the patient seeks evaluation for an inability to insert tampons or medication or because of coital difficulty. Young girls with microperforate hymen may present with postmenstrual spotting or malodorous discharge due to partial obstruction and poor drainage.

Treatment of microperforate, cribriform, or septate hymen entails resection of excess hymeneal tissue to create a functional hymeneal ring.

Transverse vaginal septum

A transverse septum represents failed canalization of the vaginal plate. This condition occurs in approximately one of every 18,000 to 30,000 women.^1,2 The septum can be located at any of various levels in the vagina; approximately 46% are found in the upper vagina, 35% to 40% in the middle portion, and 15% to 20% in the lower vagina.^1,2 Lower septa appear to be thinner than those in the proximal vagina; thinness may be due to the pressure of accumulated fluid. If a small perforation is present, the patient will experience irregular spotting.

Examination. The external genitalia appear to be normal, but the vagina is shortened. Children may present with mucocolpos, whereas adolescents develop hematocolpos. If a small perforation is present, pyohematocolpos may result from ascending infection. A mass can be palpated on rectal examination.

Ultrasonography (US) or magnetic resonance imaging (MRI) helps define the location and thickness of the septum and distinguish a high septum from congenital absence of the cervix.

Treatment. Resect a small septum and perform end-to-end anastomosis of the upper and lower edges of the vaginal wall (FIGURE 4). Only an experienced surgeon should excise a thick septum. Reanastomosis is easier if the upper vagina is distended with menstrual blood. To ensure healing without stricture, mobilize the vaginal edge circumferentially before suturing the raw edges.

Outflow obstruction caused by a transverse septum in the distal vagina almost never leads to hematometra or hematosalpinx. However, septa that arise in the proximal vagina are usually thicker and, if left untreated, can cause reflux that damages the upper reproductive tract. These cases are almost always associated with severe dysmenorrhea and should be referred to an experienced vaginal surgeon. Pelvic MRI is recommended to assess the thickness and precise anatomy of the defect before repair.

FIGURE 4 Removing a transverse vaginal septum

The septum is resected from the distal vagina. This is followed by end-to-end anastomosis of mucosal edges.

Uterine septum

A septate uterus has a normal external surface but two endometrial cavities. It is caused by a defect in fusion or resorption of the midline septum between the two müllerian ducts. The degree of septation varies from a small midline septum to a total failure of resorption that produces a septate uterus with a longitudinal vaginal septum. A slight midline septum with minimal fundal indentation is classified by some as a septate uterus; by others, as a bicornuate uterus.

A higher risk of recurrent miscarriage is associated with longer septa.

Surgical repair with hysteroscopic resection of the septum yields excellent results.

CASE 2 The problem of agenesis

An 18-year-old patient consults a gynecologist because she has never menstruated and is unable to have sexual intercourse. She appears to be phenotypically normal, with normal labia upon examination, but no hymeneal opening is found. Pelvic US reveals absence of the uterus with ovaries that appear to be normal.

How should her condition be managed?

Uterovaginal agenesis, also known as müllerian aplasia or Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome, refers to congenital absence of the vagina with variable uterine development (FIGURE 5). It arises from agenesis of the

müllerian duct system, although the underlying cause is unknown. Vaginal agenesis is usually accompanied by cervical and uterine agenesis. However, 7% to 12% of patients with this syndrome have a normal but obstructed or rudimentary uterus with functional endometrium. This condition occurs in roughly one of every 5,000 females.^1,3

In addition, these girls often exhibit extragenital anomalies.^1,4 Approximately 25% to 50% have a urologic anomaly, such as unilateral renal agenesis, pelvic or horseshoe kidneys, or irregularities of the collecting systems; 10% to 15% have another type of anomaly, such as congenital heart disease, abnormalities of the hands, congenital deafness, cleft palate, and inguinal or femoral hernia.

The genetic basis of MRKH syndrome is unknown. These patients have normal female karyotypes and phenotypes with normal ovaries and ovarian function—although there is evidence that they are prone to early menopause. They develop secondary sexual characteristics. They usually present with primary amenorrhea at 15 to 17 years of age.

Vaginal agenesis is the second most common cause of primary amenorrhea after gonadal dysgenesis. Most patients have a rudimentary, nonfunctioning uterus, but 2% to 7% have a uterus with functioning endometrium and present with cyclic or chronic abdominopelvic pain secondary to obstruction or endometriosis, hematocolpos, or hematometra.

Imaging. US examination facilitates evaluation of the kidneys and confirms the presence of ovaries and absence of the uterus. MRI may be useful to confirm the presence of functioning endometrium.

The differential diagnosis of vaginal agenesis includes androgen insensitivity and low-lying transverse vaginal septum. Treatment includes psychosocial support to reassure the patient that a normal sex life will be possible after treatment.⁵ Construction of a neovagina, using vaginal dilators (the first-line strategy) or surgical placement of split-thickness skin graft or artificial skin (Abbe–McIndoe procedure), is the treatment. In one case series, more than 90% of patients with vaginal agenesis were successfully treated using vaginal dilation.⁶

The American College of Obstetricians and Gynecologists (ACOG) recommends that patients be referred to centers with expertise in surgical creation of a neovagina.⁵

FIGURE 5 Uterine agenesis

This depiction of uterine agenesis shows small, nonfunctioning müllerian remnants and normal tubes and ovaries.

Agenesis of the lower vagina

This malformation is caused by a failure of canalization of the sinovaginal bulbs and vaginal plate. The tubes, ovaries, cervix, and upper vagina are normal, but the lower vagina is replaced by fibrous tissue. Adolescents present with primary amenorrhea accompanied by cyclic pelvic pain. A vaginal dimple may be apparent on external inspection.

Because these girls have normal cyclic pituitary–ovarian–endometrial function at menarche, the upper vagina will distend with blood and secretions, and a mass can be palpated on rectoabdominal examination. US confirms the presence of a fluid-filled mass, and MRI further defines the length of obstruction.

Treatment. Surgery (by an experienced vaginal surgeon) is best performed when a large hematocolpos is present because distention increases the amount of tissue available for pull-through.

CASE 3 Fusion failure

A 17-year-old woman complains of lower abdominal pain and an enlarging abdomen. Menarche occurred at 13 years. The patient began to notice right-sided lower abdominal pain and abdominal swelling about 2 years ago, but denies any other symptoms.

Examination reveals a mass arising from the right lateral vaginal wall. The cervix appears to be normal. US shows a large, predominantly right-sided, fluid-filled mass arising from the pelvis. The uterus appears to be didelphic, with normal ovaries and an absent right kidney.

What is the mass?

This is a classic description of uterovaginal duplication that arises when the müllerian ducts fail to fuse (FIGURE 6).

In this case, the right-sided vagina failed to canalize as well, causing a large hematocolpos. Generally, duplication is limited to the uterus and cervix (uterus didelphys bicollis), although duplication of the vulva, bladder, urethra, vagina, and anus have been described.

Women with a didelphic uterus often have a good reproductive outcome. A septated vagina occurs in 75% of cases and may cause difficulty with sexual intercourse or vaginal delivery. Symptomatic women usually opt for resection of the vaginal septum.

Women who have an obstructed hemivagina and ipsilateral renal agenesis have regular menses because menstrual blood from one uterus can exit through its unobstructed side.

Treatment involves resection of the wall of the obstructed vagina, creating a single vaginal vault. If both vaginas have failed to canalize, the patient will present much earlier, with primary amenorrhea and cyclic pelvic pain—a presentation similar to that of transverse septum. Reconstructive surgery of the uterus is not recommended for complete duplication of the uterus.^1,7

FIGURE 6 Uterus didelphys

This patient has uterus didelphys with an obstructed hemivagina.

Unicornuate and bicornuate uterus

A unicornuate uterus represents an asymmetric lateral fusion defect. One cavity is usually normal, with a fallopian tube and cervix, but the failed müllerian duct can have various configurations. The affected müllerian duct may fail to develop, or it may develop partially as a horn on the uterus or a separate structure that may or may not communicate with the uterus.

Most rudimentary horns are asymptomatic, but others contain functional endometrium that is shed cyclically. If the rudimentary horn is obstructed, as is usually the case, the woman develops cyclic or chronic abdominopelvic pain that necessitates surgical excision of the horn. Endometriosis, a result of reflux, is common.

In a bicornuate uterus, the fundus is indented and the vagina is normal. This anomaly occurs when the müllerian ducts fuse only partially. The result is varying degrees of separation of the uterine horns.

Pregnancy outcomes appear to be similar to those of the general population. However, some women develop early pregnancy loss, preterm labor, incompetent cervix, or malpresentation.

Treatment is open surgical reunification.

CASE 4 Embryonic rest cells

A 55-year-old woman complains of “fullness” in the vagina, especially during intercourse. Upon examination, a 4- to 5-cm fluid-filled cyst is visible at the right posterior fornix.

What type of cyst is it?

Gartner’s duct cysts from embryonic rest cells arise from remnants of the metanephric duct system. They usually develop on the lateral vaginal walls or fornix (FIGURE 7), unlike epidermal inclusion cysts, which are generally located on the posterior wall or at the cervical–vesical junction. Although they sometimes cause dyspareunia or make it difficult for the patient to insert a tampon, they are usually asymptomatic unless they are large. Intervention is not indicated unless the patient is symptomatic.

Treatment. Marsupialization rather than excision is the treatment of choice because these embryonic rest cells may extend deep into the retroperitoneum.

FIGURE 7 Gartner’s duct cysts

These bilateral cysts developed from embryonic rest cells.

The author reports no financial relationships relevant to this article.

CASE 1 Fluid-filled abdominal mass

A 14-year-old girl complains of crampy, episodic, lower abdominal pain of 3 months’ duration and acute retention of urine. She also reports back pain and dyschezia. She has never menstruated, but her breasts began developing 18 months earlier. Examination reveals normal Tanner stage 3 breast development and female hair distribution and a large abdominal mass. No fetal heart tones are apparent. The external genitalia appear to be normal except for a bulging mass at the introitus.

Imaging (FIGURE 1) reveals that the mass is fluid-filled. The uterus, tubes, and ovaries are present at the dome of the mass. The kidneys are normal.

What is the mass?

FIGURE 1 No exit for menstrual products

An MRI shows a large hematocolpos that develops after menarche in women who have outflow obstruction, such as imperforate hymen—as this patient had.A list of the processes involved in normal development of the female reproductive tract highlights its precarious complexity: cellular differentiation, migration, canalization, fusion, and programmed cell death. A failure in any of these processes can cause a malformation. When that malformation becomes apparent depends on the stage of life of the patient and the nature of the abnormality. As you might imagine, diagnosis and treatment are not always straightforward.

In the patient just described, the likely diagnosis is imperforate hymen or transverse vaginal septum due to failed canalization of the vaginal plate. The patient has been menstruating internally for many months and now has a large hematocolpos. Urinary retention develops when the amount of retained blood in the vagina causes acute angulation of the urethrovesical junction. Evacuation of the blood restores the physiologic angle, enabling the patient to void normally.

Most anomalies involving the external genitalia are apparent at birth (clitoromegaly, imperforate hymen), whereas obstructive and nonobstructive malformations may become evident at birth; during childhood, puberty, or adolescence; or with menarche or childbearing.

Treatment of these abnormalities has changed significantly over the past few years—largely due to refinements in diagnostic imaging, surgical and nonsurgical techniques, and instrumentation. These advances have improved reproductive function and enhanced the psychosexual attitude of these patients.

In this article, I review the most common abnormalities and describe their evaluation and management.

Just what is normal development?

Vaginal canalization

The sinovaginal bulbs are two solid evaginations originating from the urogenital sinus at the distal aspect of the müllerian tubercle, as shown at right (A). The sinovaginal bulbs proliferate into the caudal end of the uterovaginal canal to become the solid vaginal plate (B). The lumen of the lower vagina is formed by degeneration of the central cells of this vaginal plate, which occurs in a cephalad direction (C). This process of canalization is complete by 20 weeks’ gestation.

Hymen usually ruptures before birth

The vaginal hymen is separated from the urogenital sinus by the hymeneal membrane. The hymen usually ruptures before birth with the degeneration of central epithelial cells (i.e., canalization), leaving a thin fold of mucous membrane around the vaginal introitus.

Uterus, fallopian tubes develop from solid tissue

The müllerian ducts are first identifiable at approximately 6 weeks of gestation, when they begin to elongate caudally and cross the metanephric ducts medially to meet in the midline. By the seventh week, the urorectal septum has developed, separating the rectum from the urogenital sinus. Around 12 weeks’ gestation, the caudal portion of the müllerian ducts fuses to form the uterovaginal canal, which inserts into the dorsal wall of the urogenital sinus at Müller’s tubercle.

The two müllerian ducts are initially solid tissue and lie side by side. Subsequently, internal canalization of each duct produces two channels divided by a septum that is reabsorbed in a cephalad direction by 20 weeks. The cranial unfused portions of the müllerian ducts develop into the fimbria and fallopian tubes, whereas the caudal, fused portions form the uterus and upper vagina.

Impaired canalization

Imperforate hymen

The most common obstructive lesion of the female reproductive tract is an imperforate hymen. It can be diagnosed at birth with careful examination to ensure patency of both the rectum and vagina. Not infrequently, the infant presents with a bulging introitus due to mucocolpos from vaginal secretions stimulated by maternal estrogen (FIGURE 2). If diagnosis is delayed, the mucus usually resorbs and the child remains asymptomatic until menarche, when she presents with a bulging hymen and a large hematocolpos, as in the opening case. Management of imperforate hymen is feasible for the generalist. Repair can be performed in a patient of any age, but is facilitated if the tissue has undergone estrogen stimulation. Surgery is, therefore, ideal in the neonatal, postpubertal, and premenarchal periods.

Repair involves incision of the membrane near the hymeneal ring, followed by evacuation of accumulated blood. The cervix may appear to be flush with the vaginal apex, owing to compression, but this condition usually corrects itself within 2 or 3 weeks. Extra hymeneal tissue is excised to create an orifice of normal size, and the vaginal mucosa is intermittently sutured to the hymeneal ring using absorbable material (FIGURE 3).

FIGURE 2 Imperforate hymen

Bulging hymen due to mucocolpos in a newborn (top) and hematocolpos in an adolescent (bottom).

FIGURE 3 Hymenectomy restores vaginal orifice

Extra hymeneal tissue is excised to create an orifice of normal size. The vaginal mucosa is intermittently sutured to the hymeneal ring.

Incomplete hymeneal fenestration

This condition often goes undiagnosed until the patient seeks evaluation for an inability to insert tampons or medication or because of coital difficulty. Young girls with microperforate hymen may present with postmenstrual spotting or malodorous discharge due to partial obstruction and poor drainage.

Treatment of microperforate, cribriform, or septate hymen entails resection of excess hymeneal tissue to create a functional hymeneal ring.

Transverse vaginal septum

A transverse septum represents failed canalization of the vaginal plate. This condition occurs in approximately one of every 18,000 to 30,000 women.^1,2 The septum can be located at any of various levels in the vagina; approximately 46% are found in the upper vagina, 35% to 40% in the middle portion, and 15% to 20% in the lower vagina.^1,2 Lower septa appear to be thinner than those in the proximal vagina; thinness may be due to the pressure of accumulated fluid. If a small perforation is present, the patient will experience irregular spotting.

Examination. The external genitalia appear to be normal, but the vagina is shortened. Children may present with mucocolpos, whereas adolescents develop hematocolpos. If a small perforation is present, pyohematocolpos may result from ascending infection. A mass can be palpated on rectal examination.

Ultrasonography (US) or magnetic resonance imaging (MRI) helps define the location and thickness of the septum and distinguish a high septum from congenital absence of the cervix.

Treatment. Resect a small septum and perform end-to-end anastomosis of the upper and lower edges of the vaginal wall (FIGURE 4). Only an experienced surgeon should excise a thick septum. Reanastomosis is easier if the upper vagina is distended with menstrual blood. To ensure healing without stricture, mobilize the vaginal edge circumferentially before suturing the raw edges.

Outflow obstruction caused by a transverse septum in the distal vagina almost never leads to hematometra or hematosalpinx. However, septa that arise in the proximal vagina are usually thicker and, if left untreated, can cause reflux that damages the upper reproductive tract. These cases are almost always associated with severe dysmenorrhea and should be referred to an experienced vaginal surgeon. Pelvic MRI is recommended to assess the thickness and precise anatomy of the defect before repair.

FIGURE 4 Removing a transverse vaginal septum

The septum is resected from the distal vagina. This is followed by end-to-end anastomosis of mucosal edges.

Uterine septum

A septate uterus has a normal external surface but two endometrial cavities. It is caused by a defect in fusion or resorption of the midline septum between the two müllerian ducts. The degree of septation varies from a small midline septum to a total failure of resorption that produces a septate uterus with a longitudinal vaginal septum. A slight midline septum with minimal fundal indentation is classified by some as a septate uterus; by others, as a bicornuate uterus.

A higher risk of recurrent miscarriage is associated with longer septa.

Surgical repair with hysteroscopic resection of the septum yields excellent results.

CASE 2 The problem of agenesis

An 18-year-old patient consults a gynecologist because she has never menstruated and is unable to have sexual intercourse. She appears to be phenotypically normal, with normal labia upon examination, but no hymeneal opening is found. Pelvic US reveals absence of the uterus with ovaries that appear to be normal.

How should her condition be managed?

Uterovaginal agenesis, also known as müllerian aplasia or Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome, refers to congenital absence of the vagina with variable uterine development (FIGURE 5). It arises from agenesis of the

müllerian duct system, although the underlying cause is unknown. Vaginal agenesis is usually accompanied by cervical and uterine agenesis. However, 7% to 12% of patients with this syndrome have a normal but obstructed or rudimentary uterus with functional endometrium. This condition occurs in roughly one of every 5,000 females.^1,3

In addition, these girls often exhibit extragenital anomalies.^1,4 Approximately 25% to 50% have a urologic anomaly, such as unilateral renal agenesis, pelvic or horseshoe kidneys, or irregularities of the collecting systems; 10% to 15% have another type of anomaly, such as congenital heart disease, abnormalities of the hands, congenital deafness, cleft palate, and inguinal or femoral hernia.

The genetic basis of MRKH syndrome is unknown. These patients have normal female karyotypes and phenotypes with normal ovaries and ovarian function—although there is evidence that they are prone to early menopause. They develop secondary sexual characteristics. They usually present with primary amenorrhea at 15 to 17 years of age.

Vaginal agenesis is the second most common cause of primary amenorrhea after gonadal dysgenesis. Most patients have a rudimentary, nonfunctioning uterus, but 2% to 7% have a uterus with functioning endometrium and present with cyclic or chronic abdominopelvic pain secondary to obstruction or endometriosis, hematocolpos, or hematometra.

Imaging. US examination facilitates evaluation of the kidneys and confirms the presence of ovaries and absence of the uterus. MRI may be useful to confirm the presence of functioning endometrium.

The differential diagnosis of vaginal agenesis includes androgen insensitivity and low-lying transverse vaginal septum. Treatment includes psychosocial support to reassure the patient that a normal sex life will be possible after treatment.⁵ Construction of a neovagina, using vaginal dilators (the first-line strategy) or surgical placement of split-thickness skin graft or artificial skin (Abbe–McIndoe procedure), is the treatment. In one case series, more than 90% of patients with vaginal agenesis were successfully treated using vaginal dilation.⁶

The American College of Obstetricians and Gynecologists (ACOG) recommends that patients be referred to centers with expertise in surgical creation of a neovagina.⁵

FIGURE 5 Uterine agenesis

This depiction of uterine agenesis shows small, nonfunctioning müllerian remnants and normal tubes and ovaries.

Agenesis of the lower vagina

This malformation is caused by a failure of canalization of the sinovaginal bulbs and vaginal plate. The tubes, ovaries, cervix, and upper vagina are normal, but the lower vagina is replaced by fibrous tissue. Adolescents present with primary amenorrhea accompanied by cyclic pelvic pain. A vaginal dimple may be apparent on external inspection.

Because these girls have normal cyclic pituitary–ovarian–endometrial function at menarche, the upper vagina will distend with blood and secretions, and a mass can be palpated on rectoabdominal examination. US confirms the presence of a fluid-filled mass, and MRI further defines the length of obstruction.

Treatment. Surgery (by an experienced vaginal surgeon) is best performed when a large hematocolpos is present because distention increases the amount of tissue available for pull-through.

CASE 3 Fusion failure

A 17-year-old woman complains of lower abdominal pain and an enlarging abdomen. Menarche occurred at 13 years. The patient began to notice right-sided lower abdominal pain and abdominal swelling about 2 years ago, but denies any other symptoms.

Examination reveals a mass arising from the right lateral vaginal wall. The cervix appears to be normal. US shows a large, predominantly right-sided, fluid-filled mass arising from the pelvis. The uterus appears to be didelphic, with normal ovaries and an absent right kidney.

What is the mass?

This is a classic description of uterovaginal duplication that arises when the müllerian ducts fail to fuse (FIGURE 6).

In this case, the right-sided vagina failed to canalize as well, causing a large hematocolpos. Generally, duplication is limited to the uterus and cervix (uterus didelphys bicollis), although duplication of the vulva, bladder, urethra, vagina, and anus have been described.

Women with a didelphic uterus often have a good reproductive outcome. A septated vagina occurs in 75% of cases and may cause difficulty with sexual intercourse or vaginal delivery. Symptomatic women usually opt for resection of the vaginal septum.

Women who have an obstructed hemivagina and ipsilateral renal agenesis have regular menses because menstrual blood from one uterus can exit through its unobstructed side.

Treatment involves resection of the wall of the obstructed vagina, creating a single vaginal vault. If both vaginas have failed to canalize, the patient will present much earlier, with primary amenorrhea and cyclic pelvic pain—a presentation similar to that of transverse septum. Reconstructive surgery of the uterus is not recommended for complete duplication of the uterus.^1,7

FIGURE 6 Uterus didelphys

This patient has uterus didelphys with an obstructed hemivagina.

Unicornuate and bicornuate uterus

A unicornuate uterus represents an asymmetric lateral fusion defect. One cavity is usually normal, with a fallopian tube and cervix, but the failed müllerian duct can have various configurations. The affected müllerian duct may fail to develop, or it may develop partially as a horn on the uterus or a separate structure that may or may not communicate with the uterus.

Most rudimentary horns are asymptomatic, but others contain functional endometrium that is shed cyclically. If the rudimentary horn is obstructed, as is usually the case, the woman develops cyclic or chronic abdominopelvic pain that necessitates surgical excision of the horn. Endometriosis, a result of reflux, is common.

In a bicornuate uterus, the fundus is indented and the vagina is normal. This anomaly occurs when the müllerian ducts fuse only partially. The result is varying degrees of separation of the uterine horns.

Pregnancy outcomes appear to be similar to those of the general population. However, some women develop early pregnancy loss, preterm labor, incompetent cervix, or malpresentation.

Treatment is open surgical reunification.

CASE 4 Embryonic rest cells

A 55-year-old woman complains of “fullness” in the vagina, especially during intercourse. Upon examination, a 4- to 5-cm fluid-filled cyst is visible at the right posterior fornix.

What type of cyst is it?

Gartner’s duct cysts from embryonic rest cells arise from remnants of the metanephric duct system. They usually develop on the lateral vaginal walls or fornix (FIGURE 7), unlike epidermal inclusion cysts, which are generally located on the posterior wall or at the cervical–vesical junction. Although they sometimes cause dyspareunia or make it difficult for the patient to insert a tampon, they are usually asymptomatic unless they are large. Intervention is not indicated unless the patient is symptomatic.

Treatment. Marsupialization rather than excision is the treatment of choice because these embryonic rest cells may extend deep into the retroperitoneum.

FIGURE 7 Gartner’s duct cysts

These bilateral cysts developed from embryonic rest cells.

The authors report no financial relationships relevant to this article.

CASE Large baby, extensive tear

A 28-year-old primigravida undergoes a forceps delivery with a midline episiotomy for failure to progress in the second stage of labor. At birth, the infant weighs 4 kg (8.8 lb), and the episiotomy extends to the anal verge. The resident who delivered the child is uncertain whether the anal sphincter is involved in the injury and asks a consultant to examine the perineum.

What should this examination entail?

The obstetrician is rarely culpable when a third- or fourth-degree obstetric anal sphincter injury (OASIS) occurs—but there is little excuse for letting one go undetected.

To minimize the risk of undiagnosed OASIS, a digital anorectal examination is warranted—before any suturing—in every woman who delivers vaginally. This practice can help you avoid missing isolated tears, such as “buttonhole” of the rectal mucosa, which can occur even when the anal sphincter remains intact (FIGURE 1), or a third- or fourth-degree tear that can sometimes be present behind apparently intact perineal skin (FIGURE 2).¹

Clinical training of physicians and midwives also needs to improve.

Every labor room should have a protocol for management of anal sphincter injury²; this article describes detection, diagnosis, and management, focusing on seven critical questions.

Only a physician formally trained in primary anal sphincter repair (or under supervision) should repair OASIS.

FIGURE 1 Buttonhole tear

A buttonhole tear of the rectal mucosa (arrow) with an intact external anal sphincter (EAS) demonstrated during a digital rectal examination. SOURCE: Sultan AH³ (used with permission).

FIGURE 2 Injury obscured by intact skin

(A) Intact perineum on visual examination. (B) Anal sphincter trauma detected after rectal examination. SOURCE: Sultan AH, Kettle C¹ (used with permission).

1. When (and how) should the torn perineum be examined?

The first requisite is informed consent for vaginal and rectal examination immediately after delivery. Also vital are adequate exposure of the perineum, good lighting, and, if necessary, sufficient analgesia to prevent pain-related restriction of the evaluation. It may be advisable to place the patient in the lithotomy position to improve exposure.

After visual examination of the perineum, part the labia and examine the vagina to establish the full extent of the tear. Always identify the apex of the vaginal laceration.

Next, perform a rectal examination to exclude injury to the anorectal mucosa and anal sphincter.³

Palpation is necessary to confirm OASIS

Insert the index finger into the anal canal and the thumb into the vagina and perform a pill-rolling motion to palpate the anal sphincter. If this technique is inconclusive, ask the woman to contract her anal sphincter with your fingers still in place. When the sphincter is disrupted, you feel a distinct gap anteriorly. If the perineal skin is intact, there may be an absence of puckering on the perianal skin over any underlying defect that may not be evident under regional or general anesthesia.

Because the external anal sphincter (EAS) is in a state of tonic contraction, the sphincter ends will retract when it is disrupted. These ends need to be grasped and retrieved at the time of repair.

Also identify the internal anal sphincter (IAS). It is a circular smooth muscle (FIGURE 3) that is paler in appearance (similar to the flesh of raw fish) than the striated EAS (similar to raw red meat).⁴ Under normal circumstances, the distal end of the IAS lies a few millimeters proximal to the distal end of the EAS (FIGURE 4). However, if the EAS is relaxed due to regional or general anesthesia, the distal end of the IAS will appear to be at a lower level. If the IAS or anal epithelium is torn, the EAS is, invariably, torn, too.

General or regional (spinal, epidural, caudal) anesthesia provides analgesia and muscle relaxation and enables proper evaluation of the full extent of the injury.

FIGURE 3 Grade 3b tear

Grade 3b tear with an intact internal anal sphincter (IAS). The external sphincter (EAS) is being grasped with Allis forceps. Note the difference in appearance of the paler IAS and darker EAS. SOURCE: Sultan AH, Kettle C¹ (used with permission).

FIGURE 4 Classification of anal sphincter injury

First- and second-degree injuries are described below.

2. Is endoanal US helpful to detect OASIS?

Endoanal ultrasonography (US) to identify OASIS requires specific expertise, particularly in the immediate postpartum period, when the anal canal is lax (especially after an epidural). Ultimately, however, the diagnosis rests on clinical assessment and a rectal examination because, even if a defect is seen on US, it has to be clinically apparent to be repaired.

In a study by Faltin and colleagues, in which routine postpartum endoanal US was used as the gold standard for diagnosis of OASIS, five of 21 women had unnecessary intervention because the sonographic defect was not clinically visible despite exploration of the anal sphincter.⁵ As a result of this unnecessary exploration based on endoanal US, 20% of these women developed severe fecal incontinence. Therefore, we believe that OASIS is best detected clinically immediately after delivery, provided the physician performs a careful examination with palpation of the anal sphincter.⁶ In such a scenario, endoanal US is of limited value.

3. How is obstetric anal sphincter trauma classified?

To standardize the classification of perineal trauma, Sultan proposed the following system, which has been adopted by the Royal College of Obstetricians and Gynaecologists and internationally^7-9:

First degree: Laceration of the vaginal epithelium or perineal skin only

Second degree: Involvement of the perineal muscles, but not the anal sphincter

Third degree: Disruption of the anal sphincter muscles (FIGURE 4):

• 3a: Less than 50% thickness of the external sphincter is torn
• 3b: More than 50% thickness of the external sphincter is torn
• 3c: Internal sphincter is also torn

Fourth degree: A third-degree anal tear with disruption of the anal epithelium (FIGURE 4).

If there is any ambiguity about grading of the injury, the higher grade should be selected. For example, if there is uncertainty between grades 3a and 3b, the injury should be classified as Grade 3b.

4. Is an operating room necessary?

OASIS should be repaired in the operating theater, where there is access to good lighting, appropriate equipment, and aseptic conditions. In our unit, we have a specially prepared instrument tray containing:

• a Weislander self-retaining retractor
• 4 Allis tissue forceps
• McIndoe scissors
• tooth forceps
• 4 artery forceps
• stitch scissors
• a needle holder.

In addition, deep retractors (e.g., Deavers) are useful when there are associated paravaginal tears.

5. What surgical technique is recommended?

Buttonhole injury

This type of injury can occur in the rectum without disrupting the anal sphincter or perineum. It is best repaired transvaginally using interrupted Vicryl (polyglactin) sutures.

To minimize the risk of persistent rectovaginal fistula, interpose a second layer of tissue between the rectum and vagina by approximating the rectovaginal fascia. A colostomy is rarely indicated unless a large tear extends above the pelvic floor or there is gross fecal contamination of the wound.

Fourth-degree tear

Repair torn anal epithelium with interrupted Vicryl 3-0 sutures, with the knots tied in the anal lumen. Proponents of this widely described technique argue that it reduces the quantity of foreign body (knots) within the tissue and lowers the risk of infection. Concern about a foreign body probably applies to the use of catgut, which dissolves by proteolysis, rather than to newer synthetic material such as Vicryl or Dexon (polyglycolic acid), which dissolves by hydrolysis.

Subcuticular repair of anal epithelium using a transvaginal approach has also been described and could be equally effective if the terminal knots are secure.¹⁰

Sphincter muscles

Repair these muscles using 3-0 polydioxanone (PDS) dyed sutures. Compared with braided sutures, monofilament sutures are believed to lessen the risk of infection, although a randomized controlled trial revealed no difference in suture-related morbidity between Vicryl and PDS at 6 weeks postpartum.¹¹ Complete absorption of PDS takes longer than with Vicryl, with 50% tensile strength lasting more than 3 months, compared with 3 weeks for Vicryl.¹¹ To minimize suture migration, cut suture ends short and ensure that they are covered by the overlying superficial perineal muscles.

Internal anal sphincter. Repair the IAS separately from the EAS. Grasp the ends of the torn muscle using Allis forceps and perform an end-to-end repair with interrupted or mattress 3-0 PDS sutures (FIGURE 5). Overlapping repair can be technically difficult.

There is some evidence that repair of an isolated IAS defect benefits patients with established anal incontinence.

External anal sphincter. Because the EAS is normally under tonic contraction, it tends to retract when torn. Therefore, repair requires identification and grasping of the torn ends using Allis tissue forceps (FIGURE 6).

When the EAS is only partially torn (Grade 3a and some cases of Grade 3b), perform an end-to end repair using 2 or 3 mattress sutures, similar to repair of IAS injury, instead of hemostatic “figure of eight” sutures.

For a full-thickness tear (some cases of Grade 3b or 3c, or Grade 4), overlapping repair may be preferable in experienced hands. The EAS may need to be mobilized by dissecting it free of the ischioanal fat laterally using a pair of McIndoe scissors. The torn ends of the EAS can then be overlapped in “double-breasted” fashion (FIGURE 7) using PDS 3-0 sutures. Proper overlap is possible only when the full length of the torn ends is identified.

Overlapping the ends of the sphincter allows for greater surface area of contact between muscle. In contrast, end-to-end repair can be performed without identifying the full length of the EAS and may give rise to incomplete apposition. Fernando and colleagues demonstrated that, in experienced hands, early primary overlap repair carries a lower risk of fecal urgency and anal incontinence than does immediate primary end-to-end repair.^12,13

FIGURE 5 End-to-end repair

Internal anal sphincter (I) repair using mattress sutures, demonstrated on the latex Sultan model, used for training (www.perineum.net) (E, external sphincter; A, anal epithelium). SOURCE: Sultan AH, Thakar R² (used with permission).

FIGURE 6 Locating the external anal sphincter

The external sphincter (E), grasped with Allis forceps, is surrounded by the capsule (C) and lies medial to the ischioanal fat. SOURCE: Sultan AH, Thakar R² (used with permission).

FIGURE 7 Overlapping sphincter repair

Repair of a fourth degree tear (demonstrated on the Sultan model) using the overlap repair technique on the external sphincter (E). The anal epithelium (A) and the internal sphincter (I) have also been repaired. SOURCE: Sultan AH, Thakar R² (used with permission).

Perineal muscles

After repair of the sphincter, suture the perineal muscles to reconstruct the perineal body and provide support to the repaired anal sphincter. A short, deficient perineum would leave the anal sphincter more vulnerable to trauma during a subsequent vaginal delivery.

Next, suture the vaginal skin and approximate the perineal skin using Vicryl Rapide 2-0 subcuticular suture.

Examine, and document, the repair

Perform a rectal and vaginal examination to confirm adequate repair and ensure that no other tears have been missed—and that all tampons or swabs have been removed.

Make detailed notes of the findings and repair. A pro forma pictorial representation of the tears proves very useful when notes are reviewed following complications or during audit or litigation.

6. What does postoperative care entail?

Prophylactic antibiotics are common

No randomized trials have substantiated the benefits of intraoperative and postoperative antibiotics after repair of OASIS. Nevertheless, these drugs are commonly prescribed, especially after fourth- degree tears, because infection and wound breakdown could jeopardize the repair and lead to incontinence or fistula.^10,14

We prescribe intravenous broad-spectrum antibiotics such as cefuroxime and metronidazole intraoperatively and continue the drugs orally for 5 days.

Bladder catheterization is recommended

Severe perineal discomfort, especially after instrumental delivery, is a known cause of urinary retention. Moreover, after administration of regional anesthesia, it can take up to 12 hours before bladder sensation returns.

We recommend insertion of a Foley catheter for approximately 24 hours, unless medical staff can ensure that spontaneous voiding occurs at least every 3 to 4 hours without bladder overdistension.

Pain may persist after severe injury

The degree of pain following perineal trauma is related to the extent of the injury. OASIS is frequently associated with other more extensive injuries such as paravaginal tears. In one study, 91% of women continued to complain of severe perineal pain 7 days after OASIS.¹⁵

In a systematic review, Hedayati and associates found rectal analgesia, such as diclofenac sodium, to be effective at reducing pain from perineal trauma within the first 24 hours after birth; they also found that women used less additional analgesia within the first 48 hours after birth.¹⁶ Diclofenac is almost completely bound to protein, so excretion in breast milk is negligible.¹⁷

In women who have undergone repair of a fourth-degree tear, administer oral diclofenac; suppositories may be uncomfortable, and there is a theoretical risk of poor healing associated with local anti-inflammatory agents.

Avoid codeine-based preparations because they may cause constipation and lead to excessive straining and disruption of the repair.

Recommend a stool softener

It is vital that constipation be avoided as the patient heals; passage of constipated stool or fecal impaction can disrupt the repair. We prescribe a stool softener (lactulose, 15 mL twice daily) for 10 to 14 days and have encountered no problem with bowel evacuation.¹⁸

We recommend that the patient telephone a healthcare provider 24 to 48 hours after hospital discharge to confirm that bowel evacuation has occurred. If it hasn’t, we add mineral oil, magnesium hydroxide, or another oral bowel stimulant to the stool softener and bulking agent.

Mahoney and colleagues conducted a randomized trial (n=105) of constipating versus laxative regimens and found the latter to be associated with earlier and less painful first bowel motion and earlier hospital discharge.¹⁹ Nineteen percent of women following the constipating regimen had troublesome constipation (two required hospitalization for fecal impaction), compared with 5% of women receiving a laxative. There were no significant differences in continence scores, anal manometry, and endoanal US findings.

Give the patient adequate information

Before the patient is discharged from the hospital, we give her a booklet that describes the implications of OASIS and explains when and where to seek help if symptoms of infection or incontinence develop. All women also complete a validated bowel-health and quality-of-life questionnaire regarding conditions prior to the delivery. We also recommend pelvic floor and anal sphincter exercises as soon as her discomfort resolves.

Perform a comprehensive follow-up exam

All women who sustain OASIS should be assessed by a senior obstetrician 6 to 8 weeks after delivery. In our practice, these women are seen in a dedicated perineal clinic.²⁰ The clinic provides a supportive environment and increases the patient’s confidence in the team.²¹

At the clinic, each woman completes the same symptom questionnaire that she was given before hospital discharge. She then undergoes a genital examination in which the physician checks the degree of scarring, residual granulation tissue, and tenderness; ensures that the patient understands the circumstances surrounding the delivery and injury; and addresses any concerns. All women then undergo anal manometry and endoanal US (FIGURE 8). Each patient is encouraged to continue pelvic floor exercises. If she has minimal sphincter contractility, she may need electrical stimulation.

If a dedicated perineal clinic is unavailable, the patient should be given clear instructions, preferably in writing, before leaving the hospital. During the 6 weeks immediately after delivery, she should be instructed to look for signs of infection or wound dehiscence and to telephone the physician to report any increase in pain or swelling, rectal bleeding, or purulent discharge. Any incontinence of stool or flatus also should be reported.

FIGURE 8 Defect visible on US

Endoanal sonogram showing a defect in the external anal sphincter between 11 o’clock and 1 o’clock (between the yellow arrows) (S, subepithelium; E, external anal sphincter). SOURCE: Sultan AH, Thakar R² (used with permission).

7. Is vaginal delivery advisable after OASIS?

No randomized trials have determined the most appropriate mode of delivery after a third- or fourth-degree tear. We base our counseling of the patient on a completed symptom questionnaire and findings from manometry and endoanal US (FIGURE 8). If vaginal delivery is contemplated, these tests should be performed during the current pregnancy unless they were abnormal at an earlier date. FIGURE 9 is a simple flow diagram from our unit that illustrates management of subsequent delivery after OASIS.

When determining the mode of delivery, thorough counseling and clear documentation of that counseling are extremely important.

FIGURE 9 How do you determine the mode of delivery after OASIS?

Vaginal delivery is possible unless anal sphincter function is impaired

One study found that when a large sonographic defect (more than one quadrant) is present, or the squeeze-pressure increment (above resting pressure) is less than 20 mm Hg, the risk of impaired continence after a subsequent delivery increases dramatically.²²

Based on these findings, we conducted a prospective study that found no deterioration of sphincter function or increase in symptoms after vaginal delivery unless the patient had significant compromise of anal sphincter function before the pregnancy.²³ Therefore, we encourage asymptomatic women who have minimal compromise of anal sphincter function to undergo vaginal delivery.

Routine episiotomy is not protective

There is no evidence that routine episiotomy prevents recurrent OASIS. If episiotomy is deemed to be necessary—e.g., for a thick inelastic or scarred perineum—mediolateral episiotomy is preferred.

High likelihood of success in some women

Women who have minimal compromise of anal sphincter function should be counseled that they have an 88% (in centers practicing midline episiotomy) to 95% (in centers practicing mediolateral episiotomy) chance of delivering without sustaining another OASIS.^24,25 This should reassure them if they have misgivings about vaginal delivery.

Threshold for C-section is lower if additional risk factors are present

If traumatic delivery is anticipated, as in the presence of one or more additional risk factors (macrosomia, shoulder dystocia, prolonged labor, difficult instrumental delivery), cesarean section may be appropriate.

Consider emotional needs

Some women who have sustained OASIS may be scarred emotionally as well as physically and may find it difficult to cope with the thought of another vaginal delivery. These women deserve sympathy, psychological support, and consideration of their request for cesarean section.

When cesarean is a good idea

Women who have a minor degree of incontinence (e.g., fecal urgency or flatus incontinence) may be managed with dietary advice, constipating agents (loperamide or codeine phosphate), and physiotherapy or biofeedback. These women who have some degree of anal sphincter compromise but whose symptoms are controlled should be counseled that cesarean delivery is recommended (FIGURE 9).

Women who have sustained a previous third- or fourth-degree tear with subsequent severe incontinence should be offered secondary sphincter repair by a colorectal surgeon or urogynecologist with expertise in secondary sphincter repair. All subsequent deliveries by these women should be by cesarean section.

Some women with fecal incontinence may choose to complete their family before embarking on anal sphincter surgery. It remains unclear whether these women should be allowed a vaginal delivery, but it is likely that most damage has already occurred and that the risk of further injury is minimal and possibly insignificant. The benefit of cesarean delivery, if any, should be weighed against its risks for all subsequent pregnancies.

Women who have undergone a previous successful secondary sphincter repair for fecal incontinence should be delivered by cesarean delivery.⁹

Not all women fit neatly into one category

There are going to be women who do not entirely fit any of the categories described—such as those who have isolated internal sphincter defects or irritable bowel syndrome. Management of these women should be individualized, with the mode of delivery determined by mutual agreement after taking into account symptoms and clinical and other findings.

If there are no facilities for anal manometry and US, the physician should base management on symptoms and clinical evaluation. Asymptomatic women who do not have clinical evidence of sphincter compromise during anal tone assessment may be allowed to undergo vaginal delivery. All women who are symptomatic should be referred to a center with facilities for anorectal assessment to establish the ideal management and mode of delivery.

Pay attention to modifiable risk factors

In the case described at the beginning of this article, two risk factors could have been modified to minimize the patient’s risk of OASIS—namely, midline episiotomy and forceps delivery. In a quasirandomized study by Coats, involving 407 nulliparous women, which compared mediolateral and midline episiotomy (when episiotomy was necessary), tears into or through the anal sphincter occurred in 12% of women undergoing midline episiotomy and 2% of those undergoing mediolateral episiotomy.²⁶

If operative vaginal delivery is required, vacuum extraction is preferred. In a meta-analysis of randomized studies, Thakar and Eason found that fewer women have anal sphincter trauma with vacuum delivery than with forceps.²⁷ One anal sphincter tear is avoided for every 18 women delivered by vacuum extraction instead of forceps. A randomized trial conducted in the United Kingdom involving mediolateral episiotomy found severe vaginal laceration in 17% of forceps deliveries and 11% of vacuum deliveries.²⁸ A randomized controlled trial in Canada involving midline episiotomy found third- or fourth-degree tears in 29% of forceps deliveries, versus 12% of vacuum deliveries.²⁹

The authors report no financial relationships relevant to this article.

CASE Large baby, extensive tear

A 28-year-old primigravida undergoes a forceps delivery with a midline episiotomy for failure to progress in the second stage of labor. At birth, the infant weighs 4 kg (8.8 lb), and the episiotomy extends to the anal verge. The resident who delivered the child is uncertain whether the anal sphincter is involved in the injury and asks a consultant to examine the perineum.

What should this examination entail?

The obstetrician is rarely culpable when a third- or fourth-degree obstetric anal sphincter injury (OASIS) occurs—but there is little excuse for letting one go undetected.

To minimize the risk of undiagnosed OASIS, a digital anorectal examination is warranted—before any suturing—in every woman who delivers vaginally. This practice can help you avoid missing isolated tears, such as “buttonhole” of the rectal mucosa, which can occur even when the anal sphincter remains intact (FIGURE 1), or a third- or fourth-degree tear that can sometimes be present behind apparently intact perineal skin (FIGURE 2).¹

Clinical training of physicians and midwives also needs to improve.

Every labor room should have a protocol for management of anal sphincter injury²; this article describes detection, diagnosis, and management, focusing on seven critical questions.

Only a physician formally trained in primary anal sphincter repair (or under supervision) should repair OASIS.

FIGURE 1 Buttonhole tear

A buttonhole tear of the rectal mucosa (arrow) with an intact external anal sphincter (EAS) demonstrated during a digital rectal examination. SOURCE: Sultan AH³ (used with permission).

FIGURE 2 Injury obscured by intact skin

(A) Intact perineum on visual examination. (B) Anal sphincter trauma detected after rectal examination. SOURCE: Sultan AH, Kettle C¹ (used with permission).

1. When (and how) should the torn perineum be examined?

The first requisite is informed consent for vaginal and rectal examination immediately after delivery. Also vital are adequate exposure of the perineum, good lighting, and, if necessary, sufficient analgesia to prevent pain-related restriction of the evaluation. It may be advisable to place the patient in the lithotomy position to improve exposure.

After visual examination of the perineum, part the labia and examine the vagina to establish the full extent of the tear. Always identify the apex of the vaginal laceration.

Next, perform a rectal examination to exclude injury to the anorectal mucosa and anal sphincter.³

Palpation is necessary to confirm OASIS

Insert the index finger into the anal canal and the thumb into the vagina and perform a pill-rolling motion to palpate the anal sphincter. If this technique is inconclusive, ask the woman to contract her anal sphincter with your fingers still in place. When the sphincter is disrupted, you feel a distinct gap anteriorly. If the perineal skin is intact, there may be an absence of puckering on the perianal skin over any underlying defect that may not be evident under regional or general anesthesia.

Because the external anal sphincter (EAS) is in a state of tonic contraction, the sphincter ends will retract when it is disrupted. These ends need to be grasped and retrieved at the time of repair.

Also identify the internal anal sphincter (IAS). It is a circular smooth muscle (FIGURE 3) that is paler in appearance (similar to the flesh of raw fish) than the striated EAS (similar to raw red meat).⁴ Under normal circumstances, the distal end of the IAS lies a few millimeters proximal to the distal end of the EAS (FIGURE 4). However, if the EAS is relaxed due to regional or general anesthesia, the distal end of the IAS will appear to be at a lower level. If the IAS or anal epithelium is torn, the EAS is, invariably, torn, too.

General or regional (spinal, epidural, caudal) anesthesia provides analgesia and muscle relaxation and enables proper evaluation of the full extent of the injury.

FIGURE 3 Grade 3b tear

Grade 3b tear with an intact internal anal sphincter (IAS). The external sphincter (EAS) is being grasped with Allis forceps. Note the difference in appearance of the paler IAS and darker EAS. SOURCE: Sultan AH, Kettle C¹ (used with permission).

FIGURE 4 Classification of anal sphincter injury

First- and second-degree injuries are described below.

2. Is endoanal US helpful to detect OASIS?

Endoanal ultrasonography (US) to identify OASIS requires specific expertise, particularly in the immediate postpartum period, when the anal canal is lax (especially after an epidural). Ultimately, however, the diagnosis rests on clinical assessment and a rectal examination because, even if a defect is seen on US, it has to be clinically apparent to be repaired.

In a study by Faltin and colleagues, in which routine postpartum endoanal US was used as the gold standard for diagnosis of OASIS, five of 21 women had unnecessary intervention because the sonographic defect was not clinically visible despite exploration of the anal sphincter.⁵ As a result of this unnecessary exploration based on endoanal US, 20% of these women developed severe fecal incontinence. Therefore, we believe that OASIS is best detected clinically immediately after delivery, provided the physician performs a careful examination with palpation of the anal sphincter.⁶ In such a scenario, endoanal US is of limited value.

3. How is obstetric anal sphincter trauma classified?

To standardize the classification of perineal trauma, Sultan proposed the following system, which has been adopted by the Royal College of Obstetricians and Gynaecologists and internationally^7-9:

First degree: Laceration of the vaginal epithelium or perineal skin only

Second degree: Involvement of the perineal muscles, but not the anal sphincter

Third degree: Disruption of the anal sphincter muscles (FIGURE 4):

• 3a: Less than 50% thickness of the external sphincter is torn
• 3b: More than 50% thickness of the external sphincter is torn
• 3c: Internal sphincter is also torn

Fourth degree: A third-degree anal tear with disruption of the anal epithelium (FIGURE 4).

If there is any ambiguity about grading of the injury, the higher grade should be selected. For example, if there is uncertainty between grades 3a and 3b, the injury should be classified as Grade 3b.

4. Is an operating room necessary?

OASIS should be repaired in the operating theater, where there is access to good lighting, appropriate equipment, and aseptic conditions. In our unit, we have a specially prepared instrument tray containing:

• a Weislander self-retaining retractor
• 4 Allis tissue forceps
• McIndoe scissors
• tooth forceps
• 4 artery forceps
• stitch scissors
• a needle holder.

In addition, deep retractors (e.g., Deavers) are useful when there are associated paravaginal tears.

5. What surgical technique is recommended?

Buttonhole injury

This type of injury can occur in the rectum without disrupting the anal sphincter or perineum. It is best repaired transvaginally using interrupted Vicryl (polyglactin) sutures.

To minimize the risk of persistent rectovaginal fistula, interpose a second layer of tissue between the rectum and vagina by approximating the rectovaginal fascia. A colostomy is rarely indicated unless a large tear extends above the pelvic floor or there is gross fecal contamination of the wound.

Fourth-degree tear

Repair torn anal epithelium with interrupted Vicryl 3-0 sutures, with the knots tied in the anal lumen. Proponents of this widely described technique argue that it reduces the quantity of foreign body (knots) within the tissue and lowers the risk of infection. Concern about a foreign body probably applies to the use of catgut, which dissolves by proteolysis, rather than to newer synthetic material such as Vicryl or Dexon (polyglycolic acid), which dissolves by hydrolysis.

Subcuticular repair of anal epithelium using a transvaginal approach has also been described and could be equally effective if the terminal knots are secure.¹⁰

Sphincter muscles

Repair these muscles using 3-0 polydioxanone (PDS) dyed sutures. Compared with braided sutures, monofilament sutures are believed to lessen the risk of infection, although a randomized controlled trial revealed no difference in suture-related morbidity between Vicryl and PDS at 6 weeks postpartum.¹¹ Complete absorption of PDS takes longer than with Vicryl, with 50% tensile strength lasting more than 3 months, compared with 3 weeks for Vicryl.¹¹ To minimize suture migration, cut suture ends short and ensure that they are covered by the overlying superficial perineal muscles.

Internal anal sphincter. Repair the IAS separately from the EAS. Grasp the ends of the torn muscle using Allis forceps and perform an end-to-end repair with interrupted or mattress 3-0 PDS sutures (FIGURE 5). Overlapping repair can be technically difficult.

There is some evidence that repair of an isolated IAS defect benefits patients with established anal incontinence.

External anal sphincter. Because the EAS is normally under tonic contraction, it tends to retract when torn. Therefore, repair requires identification and grasping of the torn ends using Allis tissue forceps (FIGURE 6).

When the EAS is only partially torn (Grade 3a and some cases of Grade 3b), perform an end-to end repair using 2 or 3 mattress sutures, similar to repair of IAS injury, instead of hemostatic “figure of eight” sutures.

For a full-thickness tear (some cases of Grade 3b or 3c, or Grade 4), overlapping repair may be preferable in experienced hands. The EAS may need to be mobilized by dissecting it free of the ischioanal fat laterally using a pair of McIndoe scissors. The torn ends of the EAS can then be overlapped in “double-breasted” fashion (FIGURE 7) using PDS 3-0 sutures. Proper overlap is possible only when the full length of the torn ends is identified.

Overlapping the ends of the sphincter allows for greater surface area of contact between muscle. In contrast, end-to-end repair can be performed without identifying the full length of the EAS and may give rise to incomplete apposition. Fernando and colleagues demonstrated that, in experienced hands, early primary overlap repair carries a lower risk of fecal urgency and anal incontinence than does immediate primary end-to-end repair.^12,13

FIGURE 5 End-to-end repair

Internal anal sphincter (I) repair using mattress sutures, demonstrated on the latex Sultan model, used for training (www.perineum.net) (E, external sphincter; A, anal epithelium). SOURCE: Sultan AH, Thakar R² (used with permission).

FIGURE 6 Locating the external anal sphincter

The external sphincter (E), grasped with Allis forceps, is surrounded by the capsule (C) and lies medial to the ischioanal fat. SOURCE: Sultan AH, Thakar R² (used with permission).

FIGURE 7 Overlapping sphincter repair

Repair of a fourth degree tear (demonstrated on the Sultan model) using the overlap repair technique on the external sphincter (E). The anal epithelium (A) and the internal sphincter (I) have also been repaired. SOURCE: Sultan AH, Thakar R² (used with permission).

Perineal muscles

After repair of the sphincter, suture the perineal muscles to reconstruct the perineal body and provide support to the repaired anal sphincter. A short, deficient perineum would leave the anal sphincter more vulnerable to trauma during a subsequent vaginal delivery.

Next, suture the vaginal skin and approximate the perineal skin using Vicryl Rapide 2-0 subcuticular suture.

Examine, and document, the repair

Perform a rectal and vaginal examination to confirm adequate repair and ensure that no other tears have been missed—and that all tampons or swabs have been removed.

Make detailed notes of the findings and repair. A pro forma pictorial representation of the tears proves very useful when notes are reviewed following complications or during audit or litigation.

6. What does postoperative care entail?

Prophylactic antibiotics are common

No randomized trials have substantiated the benefits of intraoperative and postoperative antibiotics after repair of OASIS. Nevertheless, these drugs are commonly prescribed, especially after fourth- degree tears, because infection and wound breakdown could jeopardize the repair and lead to incontinence or fistula.^10,14

We prescribe intravenous broad-spectrum antibiotics such as cefuroxime and metronidazole intraoperatively and continue the drugs orally for 5 days.

Bladder catheterization is recommended

Severe perineal discomfort, especially after instrumental delivery, is a known cause of urinary retention. Moreover, after administration of regional anesthesia, it can take up to 12 hours before bladder sensation returns.

We recommend insertion of a Foley catheter for approximately 24 hours, unless medical staff can ensure that spontaneous voiding occurs at least every 3 to 4 hours without bladder overdistension.

Pain may persist after severe injury

The degree of pain following perineal trauma is related to the extent of the injury. OASIS is frequently associated with other more extensive injuries such as paravaginal tears. In one study, 91% of women continued to complain of severe perineal pain 7 days after OASIS.¹⁵

In a systematic review, Hedayati and associates found rectal analgesia, such as diclofenac sodium, to be effective at reducing pain from perineal trauma within the first 24 hours after birth; they also found that women used less additional analgesia within the first 48 hours after birth.¹⁶ Diclofenac is almost completely bound to protein, so excretion in breast milk is negligible.¹⁷

In women who have undergone repair of a fourth-degree tear, administer oral diclofenac; suppositories may be uncomfortable, and there is a theoretical risk of poor healing associated with local anti-inflammatory agents.

Avoid codeine-based preparations because they may cause constipation and lead to excessive straining and disruption of the repair.

Recommend a stool softener

It is vital that constipation be avoided as the patient heals; passage of constipated stool or fecal impaction can disrupt the repair. We prescribe a stool softener (lactulose, 15 mL twice daily) for 10 to 14 days and have encountered no problem with bowel evacuation.¹⁸

We recommend that the patient telephone a healthcare provider 24 to 48 hours after hospital discharge to confirm that bowel evacuation has occurred. If it hasn’t, we add mineral oil, magnesium hydroxide, or another oral bowel stimulant to the stool softener and bulking agent.

Mahoney and colleagues conducted a randomized trial (n=105) of constipating versus laxative regimens and found the latter to be associated with earlier and less painful first bowel motion and earlier hospital discharge.¹⁹ Nineteen percent of women following the constipating regimen had troublesome constipation (two required hospitalization for fecal impaction), compared with 5% of women receiving a laxative. There were no significant differences in continence scores, anal manometry, and endoanal US findings.

Give the patient adequate information

Before the patient is discharged from the hospital, we give her a booklet that describes the implications of OASIS and explains when and where to seek help if symptoms of infection or incontinence develop. All women also complete a validated bowel-health and quality-of-life questionnaire regarding conditions prior to the delivery. We also recommend pelvic floor and anal sphincter exercises as soon as her discomfort resolves.

Perform a comprehensive follow-up exam

All women who sustain OASIS should be assessed by a senior obstetrician 6 to 8 weeks after delivery. In our practice, these women are seen in a dedicated perineal clinic.²⁰ The clinic provides a supportive environment and increases the patient’s confidence in the team.²¹

At the clinic, each woman completes the same symptom questionnaire that she was given before hospital discharge. She then undergoes a genital examination in which the physician checks the degree of scarring, residual granulation tissue, and tenderness; ensures that the patient understands the circumstances surrounding the delivery and injury; and addresses any concerns. All women then undergo anal manometry and endoanal US (FIGURE 8). Each patient is encouraged to continue pelvic floor exercises. If she has minimal sphincter contractility, she may need electrical stimulation.

If a dedicated perineal clinic is unavailable, the patient should be given clear instructions, preferably in writing, before leaving the hospital. During the 6 weeks immediately after delivery, she should be instructed to look for signs of infection or wound dehiscence and to telephone the physician to report any increase in pain or swelling, rectal bleeding, or purulent discharge. Any incontinence of stool or flatus also should be reported.

FIGURE 8 Defect visible on US

Endoanal sonogram showing a defect in the external anal sphincter between 11 o’clock and 1 o’clock (between the yellow arrows) (S, subepithelium; E, external anal sphincter). SOURCE: Sultan AH, Thakar R² (used with permission).

7. Is vaginal delivery advisable after OASIS?

No randomized trials have determined the most appropriate mode of delivery after a third- or fourth-degree tear. We base our counseling of the patient on a completed symptom questionnaire and findings from manometry and endoanal US (FIGURE 8). If vaginal delivery is contemplated, these tests should be performed during the current pregnancy unless they were abnormal at an earlier date. FIGURE 9 is a simple flow diagram from our unit that illustrates management of subsequent delivery after OASIS.

When determining the mode of delivery, thorough counseling and clear documentation of that counseling are extremely important.

FIGURE 9 How do you determine the mode of delivery after OASIS?

Vaginal delivery is possible unless anal sphincter function is impaired

One study found that when a large sonographic defect (more than one quadrant) is present, or the squeeze-pressure increment (above resting pressure) is less than 20 mm Hg, the risk of impaired continence after a subsequent delivery increases dramatically.²²

Based on these findings, we conducted a prospective study that found no deterioration of sphincter function or increase in symptoms after vaginal delivery unless the patient had significant compromise of anal sphincter function before the pregnancy.²³ Therefore, we encourage asymptomatic women who have minimal compromise of anal sphincter function to undergo vaginal delivery.

Routine episiotomy is not protective

There is no evidence that routine episiotomy prevents recurrent OASIS. If episiotomy is deemed to be necessary—e.g., for a thick inelastic or scarred perineum—mediolateral episiotomy is preferred.

High likelihood of success in some women

Women who have minimal compromise of anal sphincter function should be counseled that they have an 88% (in centers practicing midline episiotomy) to 95% (in centers practicing mediolateral episiotomy) chance of delivering without sustaining another OASIS.^24,25 This should reassure them if they have misgivings about vaginal delivery.

Threshold for C-section is lower if additional risk factors are present

If traumatic delivery is anticipated, as in the presence of one or more additional risk factors (macrosomia, shoulder dystocia, prolonged labor, difficult instrumental delivery), cesarean section may be appropriate.

Consider emotional needs

Some women who have sustained OASIS may be scarred emotionally as well as physically and may find it difficult to cope with the thought of another vaginal delivery. These women deserve sympathy, psychological support, and consideration of their request for cesarean section.

When cesarean is a good idea

Women who have a minor degree of incontinence (e.g., fecal urgency or flatus incontinence) may be managed with dietary advice, constipating agents (loperamide or codeine phosphate), and physiotherapy or biofeedback. These women who have some degree of anal sphincter compromise but whose symptoms are controlled should be counseled that cesarean delivery is recommended (FIGURE 9).

Women who have sustained a previous third- or fourth-degree tear with subsequent severe incontinence should be offered secondary sphincter repair by a colorectal surgeon or urogynecologist with expertise in secondary sphincter repair. All subsequent deliveries by these women should be by cesarean section.

Some women with fecal incontinence may choose to complete their family before embarking on anal sphincter surgery. It remains unclear whether these women should be allowed a vaginal delivery, but it is likely that most damage has already occurred and that the risk of further injury is minimal and possibly insignificant. The benefit of cesarean delivery, if any, should be weighed against its risks for all subsequent pregnancies.

Women who have undergone a previous successful secondary sphincter repair for fecal incontinence should be delivered by cesarean delivery.⁹

Not all women fit neatly into one category

There are going to be women who do not entirely fit any of the categories described—such as those who have isolated internal sphincter defects or irritable bowel syndrome. Management of these women should be individualized, with the mode of delivery determined by mutual agreement after taking into account symptoms and clinical and other findings.

If there are no facilities for anal manometry and US, the physician should base management on symptoms and clinical evaluation. Asymptomatic women who do not have clinical evidence of sphincter compromise during anal tone assessment may be allowed to undergo vaginal delivery. All women who are symptomatic should be referred to a center with facilities for anorectal assessment to establish the ideal management and mode of delivery.

Pay attention to modifiable risk factors

In the case described at the beginning of this article, two risk factors could have been modified to minimize the patient’s risk of OASIS—namely, midline episiotomy and forceps delivery. In a quasirandomized study by Coats, involving 407 nulliparous women, which compared mediolateral and midline episiotomy (when episiotomy was necessary), tears into or through the anal sphincter occurred in 12% of women undergoing midline episiotomy and 2% of those undergoing mediolateral episiotomy.²⁶

If operative vaginal delivery is required, vacuum extraction is preferred. In a meta-analysis of randomized studies, Thakar and Eason found that fewer women have anal sphincter trauma with vacuum delivery than with forceps.²⁷ One anal sphincter tear is avoided for every 18 women delivered by vacuum extraction instead of forceps. A randomized trial conducted in the United Kingdom involving mediolateral episiotomy found severe vaginal laceration in 17% of forceps deliveries and 11% of vacuum deliveries.²⁸ A randomized controlled trial in Canada involving midline episiotomy found third- or fourth-degree tears in 29% of forceps deliveries, versus 12% of vacuum deliveries.²⁹

The authors report no financial relationships relevant to this article.

CASE Large baby, extensive tear

A 28-year-old primigravida undergoes a forceps delivery with a midline episiotomy for failure to progress in the second stage of labor. At birth, the infant weighs 4 kg (8.8 lb), and the episiotomy extends to the anal verge. The resident who delivered the child is uncertain whether the anal sphincter is involved in the injury and asks a consultant to examine the perineum.

What should this examination entail?

The obstetrician is rarely culpable when a third- or fourth-degree obstetric anal sphincter injury (OASIS) occurs—but there is little excuse for letting one go undetected.

To minimize the risk of undiagnosed OASIS, a digital anorectal examination is warranted—before any suturing—in every woman who delivers vaginally. This practice can help you avoid missing isolated tears, such as “buttonhole” of the rectal mucosa, which can occur even when the anal sphincter remains intact (FIGURE 1), or a third- or fourth-degree tear that can sometimes be present behind apparently intact perineal skin (FIGURE 2).¹

Clinical training of physicians and midwives also needs to improve.

Every labor room should have a protocol for management of anal sphincter injury²; this article describes detection, diagnosis, and management, focusing on seven critical questions.

Only a physician formally trained in primary anal sphincter repair (or under supervision) should repair OASIS.

FIGURE 1 Buttonhole tear

A buttonhole tear of the rectal mucosa (arrow) with an intact external anal sphincter (EAS) demonstrated during a digital rectal examination. SOURCE: Sultan AH³ (used with permission).

FIGURE 2 Injury obscured by intact skin

(A) Intact perineum on visual examination. (B) Anal sphincter trauma detected after rectal examination. SOURCE: Sultan AH, Kettle C¹ (used with permission).

1. When (and how) should the torn perineum be examined?

The first requisite is informed consent for vaginal and rectal examination immediately after delivery. Also vital are adequate exposure of the perineum, good lighting, and, if necessary, sufficient analgesia to prevent pain-related restriction of the evaluation. It may be advisable to place the patient in the lithotomy position to improve exposure.

After visual examination of the perineum, part the labia and examine the vagina to establish the full extent of the tear. Always identify the apex of the vaginal laceration.

Next, perform a rectal examination to exclude injury to the anorectal mucosa and anal sphincter.³

Palpation is necessary to confirm OASIS

Insert the index finger into the anal canal and the thumb into the vagina and perform a pill-rolling motion to palpate the anal sphincter. If this technique is inconclusive, ask the woman to contract her anal sphincter with your fingers still in place. When the sphincter is disrupted, you feel a distinct gap anteriorly. If the perineal skin is intact, there may be an absence of puckering on the perianal skin over any underlying defect that may not be evident under regional or general anesthesia.

Because the external anal sphincter (EAS) is in a state of tonic contraction, the sphincter ends will retract when it is disrupted. These ends need to be grasped and retrieved at the time of repair.

Also identify the internal anal sphincter (IAS). It is a circular smooth muscle (FIGURE 3) that is paler in appearance (similar to the flesh of raw fish) than the striated EAS (similar to raw red meat).⁴ Under normal circumstances, the distal end of the IAS lies a few millimeters proximal to the distal end of the EAS (FIGURE 4). However, if the EAS is relaxed due to regional or general anesthesia, the distal end of the IAS will appear to be at a lower level. If the IAS or anal epithelium is torn, the EAS is, invariably, torn, too.

General or regional (spinal, epidural, caudal) anesthesia provides analgesia and muscle relaxation and enables proper evaluation of the full extent of the injury.

FIGURE 3 Grade 3b tear

Grade 3b tear with an intact internal anal sphincter (IAS). The external sphincter (EAS) is being grasped with Allis forceps. Note the difference in appearance of the paler IAS and darker EAS. SOURCE: Sultan AH, Kettle C¹ (used with permission).

FIGURE 4 Classification of anal sphincter injury

First- and second-degree injuries are described below.

2. Is endoanal US helpful to detect OASIS?

Endoanal ultrasonography (US) to identify OASIS requires specific expertise, particularly in the immediate postpartum period, when the anal canal is lax (especially after an epidural). Ultimately, however, the diagnosis rests on clinical assessment and a rectal examination because, even if a defect is seen on US, it has to be clinically apparent to be repaired.

In a study by Faltin and colleagues, in which routine postpartum endoanal US was used as the gold standard for diagnosis of OASIS, five of 21 women had unnecessary intervention because the sonographic defect was not clinically visible despite exploration of the anal sphincter.⁵ As a result of this unnecessary exploration based on endoanal US, 20% of these women developed severe fecal incontinence. Therefore, we believe that OASIS is best detected clinically immediately after delivery, provided the physician performs a careful examination with palpation of the anal sphincter.⁶ In such a scenario, endoanal US is of limited value.

3. How is obstetric anal sphincter trauma classified?

To standardize the classification of perineal trauma, Sultan proposed the following system, which has been adopted by the Royal College of Obstetricians and Gynaecologists and internationally^7-9:

First degree: Laceration of the vaginal epithelium or perineal skin only

Second degree: Involvement of the perineal muscles, but not the anal sphincter

Third degree: Disruption of the anal sphincter muscles (FIGURE 4):

• 3a: Less than 50% thickness of the external sphincter is torn
• 3b: More than 50% thickness of the external sphincter is torn
• 3c: Internal sphincter is also torn

Fourth degree: A third-degree anal tear with disruption of the anal epithelium (FIGURE 4).

If there is any ambiguity about grading of the injury, the higher grade should be selected. For example, if there is uncertainty between grades 3a and 3b, the injury should be classified as Grade 3b.

4. Is an operating room necessary?

OASIS should be repaired in the operating theater, where there is access to good lighting, appropriate equipment, and aseptic conditions. In our unit, we have a specially prepared instrument tray containing:

• a Weislander self-retaining retractor
• 4 Allis tissue forceps
• McIndoe scissors
• tooth forceps
• 4 artery forceps
• stitch scissors
• a needle holder.

In addition, deep retractors (e.g., Deavers) are useful when there are associated paravaginal tears.

5. What surgical technique is recommended?

Buttonhole injury

This type of injury can occur in the rectum without disrupting the anal sphincter or perineum. It is best repaired transvaginally using interrupted Vicryl (polyglactin) sutures.

To minimize the risk of persistent rectovaginal fistula, interpose a second layer of tissue between the rectum and vagina by approximating the rectovaginal fascia. A colostomy is rarely indicated unless a large tear extends above the pelvic floor or there is gross fecal contamination of the wound.

Fourth-degree tear

Repair torn anal epithelium with interrupted Vicryl 3-0 sutures, with the knots tied in the anal lumen. Proponents of this widely described technique argue that it reduces the quantity of foreign body (knots) within the tissue and lowers the risk of infection. Concern about a foreign body probably applies to the use of catgut, which dissolves by proteolysis, rather than to newer synthetic material such as Vicryl or Dexon (polyglycolic acid), which dissolves by hydrolysis.

Subcuticular repair of anal epithelium using a transvaginal approach has also been described and could be equally effective if the terminal knots are secure.¹⁰

Sphincter muscles

Repair these muscles using 3-0 polydioxanone (PDS) dyed sutures. Compared with braided sutures, monofilament sutures are believed to lessen the risk of infection, although a randomized controlled trial revealed no difference in suture-related morbidity between Vicryl and PDS at 6 weeks postpartum.¹¹ Complete absorption of PDS takes longer than with Vicryl, with 50% tensile strength lasting more than 3 months, compared with 3 weeks for Vicryl.¹¹ To minimize suture migration, cut suture ends short and ensure that they are covered by the overlying superficial perineal muscles.

Internal anal sphincter. Repair the IAS separately from the EAS. Grasp the ends of the torn muscle using Allis forceps and perform an end-to-end repair with interrupted or mattress 3-0 PDS sutures (FIGURE 5). Overlapping repair can be technically difficult.

There is some evidence that repair of an isolated IAS defect benefits patients with established anal incontinence.

External anal sphincter. Because the EAS is normally under tonic contraction, it tends to retract when torn. Therefore, repair requires identification and grasping of the torn ends using Allis tissue forceps (FIGURE 6).

When the EAS is only partially torn (Grade 3a and some cases of Grade 3b), perform an end-to end repair using 2 or 3 mattress sutures, similar to repair of IAS injury, instead of hemostatic “figure of eight” sutures.

For a full-thickness tear (some cases of Grade 3b or 3c, or Grade 4), overlapping repair may be preferable in experienced hands. The EAS may need to be mobilized by dissecting it free of the ischioanal fat laterally using a pair of McIndoe scissors. The torn ends of the EAS can then be overlapped in “double-breasted” fashion (FIGURE 7) using PDS 3-0 sutures. Proper overlap is possible only when the full length of the torn ends is identified.

Overlapping the ends of the sphincter allows for greater surface area of contact between muscle. In contrast, end-to-end repair can be performed without identifying the full length of the EAS and may give rise to incomplete apposition. Fernando and colleagues demonstrated that, in experienced hands, early primary overlap repair carries a lower risk of fecal urgency and anal incontinence than does immediate primary end-to-end repair.^12,13

FIGURE 5 End-to-end repair

Internal anal sphincter (I) repair using mattress sutures, demonstrated on the latex Sultan model, used for training (www.perineum.net) (E, external sphincter; A, anal epithelium). SOURCE: Sultan AH, Thakar R² (used with permission).

FIGURE 6 Locating the external anal sphincter

The external sphincter (E), grasped with Allis forceps, is surrounded by the capsule (C) and lies medial to the ischioanal fat. SOURCE: Sultan AH, Thakar R² (used with permission).

FIGURE 7 Overlapping sphincter repair

Repair of a fourth degree tear (demonstrated on the Sultan model) using the overlap repair technique on the external sphincter (E). The anal epithelium (A) and the internal sphincter (I) have also been repaired. SOURCE: Sultan AH, Thakar R² (used with permission).

Perineal muscles

After repair of the sphincter, suture the perineal muscles to reconstruct the perineal body and provide support to the repaired anal sphincter. A short, deficient perineum would leave the anal sphincter more vulnerable to trauma during a subsequent vaginal delivery.

Next, suture the vaginal skin and approximate the perineal skin using Vicryl Rapide 2-0 subcuticular suture.

Examine, and document, the repair

Perform a rectal and vaginal examination to confirm adequate repair and ensure that no other tears have been missed—and that all tampons or swabs have been removed.

Make detailed notes of the findings and repair. A pro forma pictorial representation of the tears proves very useful when notes are reviewed following complications or during audit or litigation.

6. What does postoperative care entail?

Prophylactic antibiotics are common

No randomized trials have substantiated the benefits of intraoperative and postoperative antibiotics after repair of OASIS. Nevertheless, these drugs are commonly prescribed, especially after fourth- degree tears, because infection and wound breakdown could jeopardize the repair and lead to incontinence or fistula.^10,14

We prescribe intravenous broad-spectrum antibiotics such as cefuroxime and metronidazole intraoperatively and continue the drugs orally for 5 days.

Bladder catheterization is recommended

Severe perineal discomfort, especially after instrumental delivery, is a known cause of urinary retention. Moreover, after administration of regional anesthesia, it can take up to 12 hours before bladder sensation returns.

We recommend insertion of a Foley catheter for approximately 24 hours, unless medical staff can ensure that spontaneous voiding occurs at least every 3 to 4 hours without bladder overdistension.

Pain may persist after severe injury

The degree of pain following perineal trauma is related to the extent of the injury. OASIS is frequently associated with other more extensive injuries such as paravaginal tears. In one study, 91% of women continued to complain of severe perineal pain 7 days after OASIS.¹⁵

In a systematic review, Hedayati and associates found rectal analgesia, such as diclofenac sodium, to be effective at reducing pain from perineal trauma within the first 24 hours after birth; they also found that women used less additional analgesia within the first 48 hours after birth.¹⁶ Diclofenac is almost completely bound to protein, so excretion in breast milk is negligible.¹⁷

In women who have undergone repair of a fourth-degree tear, administer oral diclofenac; suppositories may be uncomfortable, and there is a theoretical risk of poor healing associated with local anti-inflammatory agents.

Avoid codeine-based preparations because they may cause constipation and lead to excessive straining and disruption of the repair.

Recommend a stool softener

It is vital that constipation be avoided as the patient heals; passage of constipated stool or fecal impaction can disrupt the repair. We prescribe a stool softener (lactulose, 15 mL twice daily) for 10 to 14 days and have encountered no problem with bowel evacuation.¹⁸

We recommend that the patient telephone a healthcare provider 24 to 48 hours after hospital discharge to confirm that bowel evacuation has occurred. If it hasn’t, we add mineral oil, magnesium hydroxide, or another oral bowel stimulant to the stool softener and bulking agent.

Mahoney and colleagues conducted a randomized trial (n=105) of constipating versus laxative regimens and found the latter to be associated with earlier and less painful first bowel motion and earlier hospital discharge.¹⁹ Nineteen percent of women following the constipating regimen had troublesome constipation (two required hospitalization for fecal impaction), compared with 5% of women receiving a laxative. There were no significant differences in continence scores, anal manometry, and endoanal US findings.

Give the patient adequate information

Before the patient is discharged from the hospital, we give her a booklet that describes the implications of OASIS and explains when and where to seek help if symptoms of infection or incontinence develop. All women also complete a validated bowel-health and quality-of-life questionnaire regarding conditions prior to the delivery. We also recommend pelvic floor and anal sphincter exercises as soon as her discomfort resolves.

Perform a comprehensive follow-up exam

All women who sustain OASIS should be assessed by a senior obstetrician 6 to 8 weeks after delivery. In our practice, these women are seen in a dedicated perineal clinic.²⁰ The clinic provides a supportive environment and increases the patient’s confidence in the team.²¹

At the clinic, each woman completes the same symptom questionnaire that she was given before hospital discharge. She then undergoes a genital examination in which the physician checks the degree of scarring, residual granulation tissue, and tenderness; ensures that the patient understands the circumstances surrounding the delivery and injury; and addresses any concerns. All women then undergo anal manometry and endoanal US (FIGURE 8). Each patient is encouraged to continue pelvic floor exercises. If she has minimal sphincter contractility, she may need electrical stimulation.

If a dedicated perineal clinic is unavailable, the patient should be given clear instructions, preferably in writing, before leaving the hospital. During the 6 weeks immediately after delivery, she should be instructed to look for signs of infection or wound dehiscence and to telephone the physician to report any increase in pain or swelling, rectal bleeding, or purulent discharge. Any incontinence of stool or flatus also should be reported.

FIGURE 8 Defect visible on US

Endoanal sonogram showing a defect in the external anal sphincter between 11 o’clock and 1 o’clock (between the yellow arrows) (S, subepithelium; E, external anal sphincter). SOURCE: Sultan AH, Thakar R² (used with permission).

7. Is vaginal delivery advisable after OASIS?

No randomized trials have determined the most appropriate mode of delivery after a third- or fourth-degree tear. We base our counseling of the patient on a completed symptom questionnaire and findings from manometry and endoanal US (FIGURE 8). If vaginal delivery is contemplated, these tests should be performed during the current pregnancy unless they were abnormal at an earlier date. FIGURE 9 is a simple flow diagram from our unit that illustrates management of subsequent delivery after OASIS.

When determining the mode of delivery, thorough counseling and clear documentation of that counseling are extremely important.

FIGURE 9 How do you determine the mode of delivery after OASIS?

Vaginal delivery is possible unless anal sphincter function is impaired

One study found that when a large sonographic defect (more than one quadrant) is present, or the squeeze-pressure increment (above resting pressure) is less than 20 mm Hg, the risk of impaired continence after a subsequent delivery increases dramatically.²²

Based on these findings, we conducted a prospective study that found no deterioration of sphincter function or increase in symptoms after vaginal delivery unless the patient had significant compromise of anal sphincter function before the pregnancy.²³ Therefore, we encourage asymptomatic women who have minimal compromise of anal sphincter function to undergo vaginal delivery.

Routine episiotomy is not protective

There is no evidence that routine episiotomy prevents recurrent OASIS. If episiotomy is deemed to be necessary—e.g., for a thick inelastic or scarred perineum—mediolateral episiotomy is preferred.

High likelihood of success in some women

Women who have minimal compromise of anal sphincter function should be counseled that they have an 88% (in centers practicing midline episiotomy) to 95% (in centers practicing mediolateral episiotomy) chance of delivering without sustaining another OASIS.^24,25 This should reassure them if they have misgivings about vaginal delivery.

Threshold for C-section is lower if additional risk factors are present

If traumatic delivery is anticipated, as in the presence of one or more additional risk factors (macrosomia, shoulder dystocia, prolonged labor, difficult instrumental delivery), cesarean section may be appropriate.

Consider emotional needs

Some women who have sustained OASIS may be scarred emotionally as well as physically and may find it difficult to cope with the thought of another vaginal delivery. These women deserve sympathy, psychological support, and consideration of their request for cesarean section.

When cesarean is a good idea

Women who have a minor degree of incontinence (e.g., fecal urgency or flatus incontinence) may be managed with dietary advice, constipating agents (loperamide or codeine phosphate), and physiotherapy or biofeedback. These women who have some degree of anal sphincter compromise but whose symptoms are controlled should be counseled that cesarean delivery is recommended (FIGURE 9).

Women who have sustained a previous third- or fourth-degree tear with subsequent severe incontinence should be offered secondary sphincter repair by a colorectal surgeon or urogynecologist with expertise in secondary sphincter repair. All subsequent deliveries by these women should be by cesarean section.

Some women with fecal incontinence may choose to complete their family before embarking on anal sphincter surgery. It remains unclear whether these women should be allowed a vaginal delivery, but it is likely that most damage has already occurred and that the risk of further injury is minimal and possibly insignificant. The benefit of cesarean delivery, if any, should be weighed against its risks for all subsequent pregnancies.

Women who have undergone a previous successful secondary sphincter repair for fecal incontinence should be delivered by cesarean delivery.⁹

Not all women fit neatly into one category

There are going to be women who do not entirely fit any of the categories described—such as those who have isolated internal sphincter defects or irritable bowel syndrome. Management of these women should be individualized, with the mode of delivery determined by mutual agreement after taking into account symptoms and clinical and other findings.

If there are no facilities for anal manometry and US, the physician should base management on symptoms and clinical evaluation. Asymptomatic women who do not have clinical evidence of sphincter compromise during anal tone assessment may be allowed to undergo vaginal delivery. All women who are symptomatic should be referred to a center with facilities for anorectal assessment to establish the ideal management and mode of delivery.

Pay attention to modifiable risk factors

In the case described at the beginning of this article, two risk factors could have been modified to minimize the patient’s risk of OASIS—namely, midline episiotomy and forceps delivery. In a quasirandomized study by Coats, involving 407 nulliparous women, which compared mediolateral and midline episiotomy (when episiotomy was necessary), tears into or through the anal sphincter occurred in 12% of women undergoing midline episiotomy and 2% of those undergoing mediolateral episiotomy.²⁶

If operative vaginal delivery is required, vacuum extraction is preferred. In a meta-analysis of randomized studies, Thakar and Eason found that fewer women have anal sphincter trauma with vacuum delivery than with forceps.²⁷ One anal sphincter tear is avoided for every 18 women delivered by vacuum extraction instead of forceps. A randomized trial conducted in the United Kingdom involving mediolateral episiotomy found severe vaginal laceration in 17% of forceps deliveries and 11% of vacuum deliveries.²⁸ A randomized controlled trial in Canada involving midline episiotomy found third- or fourth-degree tears in 29% of forceps deliveries, versus 12% of vacuum deliveries.²⁹

The authors report no financial relationships relevant to this article.

The adverse consequences of obesity go far beyond aesthetic and psychosocial concerns. Patients who are markedly overweight face a real risk of developing severe health conditions—not just cardiac disease, diabetes mellitus, and hypertension, but also sleep apnea, venous thromboembolism, certain cancers (particularly breast and uterine), and biliary tract disease. Obesity also contributes to menstrual abnormalities and infertility and may complicate pregnancy.

Surgery in these patients poses a number of challenges. Not only does obesity frequently compromise the technical aspects of a procedure, it requires the surgeon to use certain measures in the preoperative and postoperative phases of management, such as counseling the patient extensively about the risks and potential complications she faces, initiating antibiotic prophylaxis, and ensuring early ambulation. These and other measures are especially important when uncontrolled, coexisting disease is present.

Not every obese patient is a significant surgical risk, so care should be individualized and use a team approach involving the gynecologist, anesthesiologist, primary care physician, and other appropriate subspecialists.

This article outlines the parameters of good surgical care in the obese patient, defined here as having a body mass index (BMI) of 30 kg/m² or above, or 35 kg/m² or above for morbid obesity. Whenever possible, we draw our recommendations from the published literature. In the absence of data, we base them on our surgical experience in the obese population.

Risks of surgery

It is imperative for the gynecologic surgeon to discuss the special risks of surgery with the obese patient well in advance of the operation and to formulate a systematic plan for evaluation, utilizing other members of the team when necessary. If the surgeon keeps the following risks in mind and is proactive, complications can be kept to a minimum.

Poor wound healing

Wound healing is a complex process involving several concurrent phases; an abnormality in any phase may impair healing. Those phases are:

• inflammatory phase, in which fluid and cells are released to clean the wound and prepare for the next phase of healing
• fibroplastic (proliferative) phase, in which fibroblasts accumulate and form collagen, the building block of connective tissue. This stage is marked by neovascularization and increased formation of granulation tissue
• wound contraction
• remodeling/maturation, in which new collagen is laid down as old collagen is broken down, resulting in scar formation.

Obese patients possess a thick layer of adipose tissue, which by its nature and location is minimally vascularized. This tissue essentially becomes dead space, an ideal medium for bacterial growth. Many obese patients also have diabetes mellitus, malignancy, or other comorbidity that further impairs healing.

As a result, obese patients are at increased risk of wound complications, breakdown, and subsequent dehiscence and evisceration. This translates into increased febrile morbidity, prolonged hospitalization, and higher cost.

What the data show. A number of studies have documented a higher incidence of wound complications in obese patients. In one retrospective review, Gallup¹ observed an increased risk of wound complications in obese patients, but the incidence diminished after implementation of a protocol of meticulous cleansing, subcutaneous heparin, and modified incision and closure techniques. In a similar retrospective study of 300 obese patients, Pitkin² reported wound complications among approximately one third of patients and postoperative fever among more than three quarters. Surgical-site infections are thought to occur in as many as 5% of patients.

Prophylaxis may be effective in some patients, but can be challenging. It entails meticulous skin cleansing and careful consideration of where the incision is placed, type of closure, use of a drain, and antibiotic administration.

Antibiotic prophylaxis is based on the theory that its presence in host tissues will alter natural defense mechanisms and kill bacteria that inoculate the wound. Because the window of efficacy is narrow, antibiotics should be administered shortly before the time of inoculation (ie, shortly before the time of incision, vaginal entry, etc.). Current guidelines suggest the use of broad-spectrum agents, including a cephalosporin, approximately 60 minutes before the incision. Redosing is recommended for procedures that last longer than 3 hours, as well as for those that involve significant blood loss (>1,500 mL).

For surgical procedures other than hysterectomy and laparotomy, prophylaxis may not be warranted.³ However, when the patient is markedly obese, many surgeons, including me (Dr. Perkins), sometimes opt to give antibiotics anyway—except for laparoscopic procedures—primarily for wound healing.

Compromised operative exposure

One of the main challenges of surgery in the obese is achieving adequate exposure; when it is inadequate, inadvertent injury may occur.

In addition to a thick abdominal wall composed largely of adipose tissue, these patients frequently have significant accumulations of fat in the mesenteries of the bowel, omentum, and pelvic peritoneum. These accumulations make it difficult to navigate around what becomes a narrow operative field.

Exposure can also be limited in vaginal surgery, because many obese women have very large thighs, buttocks, and accumulations of perineal fat.

Because exposure is a key element of successful surgery, modification of the procedure often becomes necessary—eg, focusing on a single area of the operative field at a time.

Use of a special retractor may help. A self-retaining retractor can be extremely useful. The Bookwalter retractor, first described in 1980, is a commonly used, table-fixed system that attaches to the side rail and can be assembled in minutes (FIGURE 1).⁴ The variety of rings and blades allows for excellent exposure. Although several complications have been associated with use of the Bookwalter retractor (primarily colon perforation and neuropathy⁵), they are infrequent and can be minimized by selecting the appropriate blade size and periodically repositioning the blades.

When this or other table-fixed retractors are unavailable, two Balfour retractors, placed at opposite poles of the field to obtain satisfactory exposure, may suffice. With a morbidly obese patient, multiple assistants may still be required to facilitate optimal exposure.

FIGURE 1 A tool to increase exposure

This self-retaining Bookwalter retractor is fixed to the surgical table and features a variety of rings and blades to facilitate exposure.

Thromboembolism

Venous thromboembolism is a major cause of mortality and morbidity in hospitalized patients, causing approximately 60,000 deaths every year.⁶ Obesity increases the risk of deep venous thrombosis in patients undergoing pelvic surgery. Because of their weight—and, often, coexisting conditions such as cardiorespiratory disease—many obese women are inactive or minimally active postoperatively, increasing the risk of thromboembolism, which remains heightened as long as 3 weeks after discharge. Older women are also at high risk, as are those with a malignancy.

Current guidelines call for the application of a pneumatic calf-compression device in the operating room, with removal after the patient is fully ambulatory. I (Dr. Perkins) also advocate simultaneous use of low-dose heparin, which should be given before surgery and continued until discharge.

Although the use of unfractionated heparin in conjunction with spinal or epidural anesthesia is not a major concern, the use of low-molecular-weight heparin warrants consultation with the anesthesiologist. Unfractionated heparin is preferred because it is metabolized much more rapidly than low-molecular weight heparin.⁷ The main concern with use of heparin in this setting (regardless of the patient’s weight) is spinal hematoma formation.

Inadvertent injury

Because exposure tends to be limited in obese patients, there is an ever-present risk of injury to bowel, bladder, ureter, and vascular structures. In obese women with a history of abdominal surgery, adhesions are likely, and the risk of bowel injury is increased. Similarly, in obese patients undergoing a laparoscopic procedure, many surface landmarks and vessels may be hard to discern.

Consider preoperative bowel preparation when there is a high risk of intestinal injury.⁸

Panniculectomy: Old technique with a new surgical purpose

Use a scalpel to incise the skin and delineate the area to be excised. That area typically consists of a large wedge of abdominal skin and subcutaneous fat.

Although the addition of panniculectomy to gynecologic surgery in the morbidly obese patient is a fairly recent strategy to increase exposure, the procedure itself has roots in the 19th century. In 1910, Howard Kelly of The Johns Hopkins Hospital reported a lipectomy that involved excision of a large wedge of abdominal skin and fat,²¹ although indications for that lipectomy appear to have been grounded in cosmesis and personal comfort for the patient.

Technique

Panniculectomy involves excision of a large portion of abdominal skin and subcutaneous fat down to, but not including, the rectus fascia, to gain much greater exposure to the lower abdominal cavity and pelvis.

Once the segment to be excised is delineated, it is mobilized using electrocautery to achieve meticulous hemostasis. After all surgical procedures are completed, the abdominal wall is closed in multiple layers, and drains are placed in the subcutaneous layer. Surgeons who have performed this procedure report significantly increased exposure and access to pelvic structures.

Once the skin is incised, the wedge is mobilized using electrocautery, down to, but not including, the rectus fascia.

Risks

The most important risk is impaired healing of the abdominal wound. One study of this procedure in patients on a gynecologic oncology service noted wound complications in 35% of patients, as well as significant blood loss (up to 1,800 mL in one case).²² Another study by Hopkins and associates,²³ however, reported minimal blood loss and wound complications.

Caveats

The procedure requires an experienced surgeon, particularly if no plastic surgeon is readily available. Also, when counseling the patient about this procedure, it is important to emphasize that its primary indication is to maximize exposure; cosmetic benefits are secondary.

Impaired cardiorespiratory function

Pulmonary function typically is compromised in the markedly obese, with restrictive lung disease and reduced functional residual capacity. If the patient smokes or has chronic obstructive lung disease, her pulmonary function is compromised even further, and her condition should be relayed to the anesthesiologist.

In addition, many obese patients have preexisting heart disease or conditions such as hyperlipidemia that put them at risk for heart disease. When evaluating an obese surgical patient, also ask about less apparent disorders, such as sleep apnea, which, if not addressed, may have grave postoperative consequences.

Preoperative evaluation and preparation

Goal: Assess and minimize risks

This process begins in the office or clinic with a discussion with the patient of any concerns and risks. The importance of early mobilization and ambulation after surgery should be emphasized. Any patient with uncontrolled diabetes or hypertension should continue to be monitored by her primary care physician. A patient who has not seen a physician recently should be assessed by an internist to ensure that no conditions go undetected before surgery.

Routine testing to start, but additional assessment may be justified. An obese patient should undergo the same routine testing as a woman of normal weight, but further testing may be warranted for any coexisting disorder. Because the obese patient may have a restrictive lung pattern by virtue of her body habitus, pulmonary-function testing is unlikely to yield new information and is probably not indicated—unless she smokes or has a history of chronic obstructive pulmonary disease. In that case, tests will clarify the obstructive component and bronchodilator response and are useful in postoperative management. Measurement of arterial blood gases is useful, however, because levels reflect respiratory function on a day-to-day basis.

Additional tests of cardiac status probably are not indicated on the basis of obesity alone. However, if initial tests (eg, the electrocardiogram) and the history suggest compromised cardiac function, two-dimensional echocardiography should be performed to determine the ejection fraction. Any concerns regarding cardiac function should be discussed with the anesthesiologist and cardiologist.

Because compromised pulmonary function is likely, I (Dr. Perkins) instruct each patient on the use of incentive spirometry before she undergoes anesthesia so that she has realistic expectations about the postoperative course. I also administer heparin at least 2 hours before induction (8 hours before induction if unfractionated heparin is used).⁶

If a hysterectomy or prolonged laparotomy is planned, prophylactic antibiotics are recommended.³ Thigh-high compression stockings or a pneumatic calf-compression device should be applied upon arrival in the operating room.

Anesthesia-related issues

Anticipate challenges involving the airway

The anesthesiologist’s primary concern in regard to the obese patient is establishment and maintenance of an airway to promote oxygenation. In morbidly and extremely morbidly obese patients, anatomic factors such as large breasts; a short, thick neck; large tongue; decreased mobility of the cervical spine; limited mouth opening; and greater amount of adipose tissue in the face and cheeks can render mask ventilation and intubation extremely difficult or impossible. Decreased functional residual capacity and tidal volume in the range of closing capacity may lead to extremely rapid oxygen desaturation when the patient is apneic.⁹

If the patient is pregnant, factors such as excess adipose tissue in the face become even more pronounced and increase the potential for catastrophe.

Appreciate mechanical concerns

The morbidly obese patient may exceed the weight limit of the operating table. In addition, placing her in a steep Trendelenburg position or rotating her laterally may compromise the integrity of the bed.

Coexisting disease, such as sleep apnea and acid reflux disease, should also be kept in mind. Compromised respiratory mechanics (eg, restrictive lung pattern) may cause further deterioration and make mechanical ventilation more difficult.

It also may be hard to establish vascular access, necessitating central venous line placement and introducing its associated risks.

Keep the anesthesiologist in the loop

In the postoperative period, obese patients face a heightened risk of complications related to diminished pulmonary function, such as oxygen desaturation, hypoventilation, and airway obstruction, which may lead to atelectasis, pneumonia, and pulmonary edema.^10,11 For these reasons, early consultation with the anesthesiologist is recommended, especially if the initial evaluation suggests potential difficulties in securing the airway. In turn, the anesthesiologist should understand that, in some obese patients, even establishing a surgical airway may be difficult. Regional anesthesia should be considered when feasible.

Antacids and drugs that increase gastric motility have proved to be useful in minimizing aspiration-related risks.^12,13

Surgical technique

Begin abdominal procedures by carefully choosing an incision

Do not base the decision solely on the degree of obesity, but also consider any additional procedures that are planned, such as lymph-node sampling. A vertical incision does permit greater exposure than is afforded by a transverse incision, but in some cases the latter may be more appropriate—even if the patient is morbidly obese.

Do not place the incision below the panniculus, in the crease just above the suprapubic mound, though it may be tempting to do so when the panniculus is large and thick. This area is a warm, moist, anaerobic environment that promotes the proliferation of numerous micro-organisms, creating a bacterial cesspool. It is the worst place to make an incision.

If a transverse incision is selected, place caudal traction on the panniculus (which may be facilitated by applying two towel clips to the tissue fold), and incise through the fold at a point approximately three to four fingerbreadths above the symphysis (FIGURE 2).

If a midline incision is selected, a similar technique is appropriate, with downward traction applied to the panniculus and the incision begun at the lower pole of this fold up to the umbilicus—or through it and above, should more room be required.¹⁴

After incising the superficial fascia, greater exposure may be gained by incising the rectus sheath beneath the pannicular fold and extending it down to the symphysis. After entering the abdominal cavity, the surgeon may encounter a redundant, fat-laden layer of peritoneum. The edges of this tissue may be temporarily sutured to the edges of the skin incision to remove it from the operative field and obtain better visualization.

FIGURE 2 Incision placement can be counterintuitive

Avoid placing the skin incision beneath the panniculus, an anaerobic area ripe for infection. Instead, retract the panniculus caudally and incise the skin above the fold, as shown.

A few remedies can help when exposure is limited

Exposure is one of the most important elements of successful surgery, but it is often restricted when marked obesity is present. Fortunately, numerous adjuncts are available to address this problem, such as the table-fixed retractor systems described earlier in this article, or one or more of the following tactics:

• Do not try to expose the entire pelvic basin. One technique to ease exploration—especially when more than one procedure is planned—is to refrain from exposing the entire pelvic basin at one time. Instead, focus on obtaining adequate visualization in the immediate area and, once work in that area is finished, concentrate on the next.
• Use extra-long instruments in an extremely large patient, especially if she has a “deep” pelvis.
• Abbreviate the procedure, if possible. Because these cases are technically more difficult and frequently involve excessive blood loss, it may be wiser to perform an “incomplete” procedure, such as supracervical hysterectomy instead of total hysterectomy, depending on the indication.¹⁴
• Use a cell-saver blood-collection system if significant blood loss is anticipated. Also remember to give a second dose of prophylactic antibiotic.

Strategies for effective wound closure

The best method of abdominal wound closure has been a subject of debate among both gynecologic and general surgeons. In the obese patient, the key variables are the rather thick subcutaneous fat layer within the abdominal wall and the impact of intra-abdominal pressure on the incision.

What the data show. A number of studies, including one by Montz and colleagues,¹⁵ have demonstrated that the running mass-closure technique using delayed-absorbable or permanent suture is just as effective as interrupted suture placement (eg, Smead-Jones closure) but is faster, with less suture deposited in the wound.

The following considerations may also be helpful:

• Approximate the subcutaneous fascia? There has been some debate about whether the subcutaneous fascia must be approximated. My (Dr. Perkins) personal preference in morbidly obese patients is to place several interrupted sutures to obliterate much of the dead space, facilitate skin closure, and minimize tension on the wound; I have noted no significant increase in wound complications using this technique. Placement of a closed-suction drain (eg, Jackson Pratt, Hemovac) is a good alternative.
• Is a drain useful? Some have questioned whether use of a drain increases the likelihood of wound complications,¹⁶ but this concern is irrelevant because, in most—if not all—cases, the drainage tubing is exteriorized via a separate stab wound remote from the incision.
• Consider retention sutures. A morbidly obese patient may benefit from through-and-through retention sutures using 0 or #1 permanent material along with rubber bolsters to minimize cutting of the suture into the skin, especially if increased intra-abdominal pressure is likely (FIGURE 3).¹⁷ These sutures can be removed on the 10th to 12th postoperative day.

FIGURE 3 Minimize tension on the wound

A morbidly obese patient may benefit from through-and-through retention sutures along with rubber bolsters to minimize cutting of the suture into the skin.

Vaginal surgery does not increase complication rate in the obese

The vaginal approach can be extremely challenging in the morbidly obese patient, especially when hysterectomy is performed. Exposure is often compromised by the large folds about the thighs and buttocks, limiting access to the perineum and vaginal vault. If the patient also has a narrow, contracted pelvis, the difficulty is compounded. Because of these and other concerns about morbidity, many gynecologists hesitate to perform hysterectomy via the vaginal route when the patient is obese.

What the data show. Several studies have addressed these issues, including one by Pratt and Daikoku¹⁸ and another by Rafii and colleagues,¹⁹ both of which demonstrated that obese patients have a complication rate roughly equivalent to that observed in patients of normal weight, although obese patients have a greater decrease in hemoglobin level and a slightly higher incidence of postoperative fever.

Similarly, in a retrospective study, Pitkin²⁰ found no significant difference between the complication rates of obese and nonobese patients.

Another argument for the self-retaining retractor. From a technical standpoint, achieving good exposure is the primary challenge of vaginal surgery and usually requires two or more assistants—who themselves have limited or no direct view of the field—who must stand for long periods. Again, a viable alternative is use of a self-retaining retractor. One in particular, the MiniOmni retractor, is a small, uncumbersome, table-fixed system that can be maneuvered so that vaginal and perineal structures are readily accessible.

Choice of stirrups is also relevant. Exposure can be affected by the type of stirrups used. “Candy cane” stirrups facilitate exposure more than fixed stirrups (eg, Allen stirrups) do. Regardless of the stirrups selected, however, it is important to avoid excessive or prolonged hip flexion, or nerve injury may result.

How to minimize postoperative complications

After surgery, an obese patient requires close and continuous monitoring to avert complications and detect any that occur. Consider the following measures:

• A stint in the intensive care unit. In the morbidly obese patient, massive fluid shift (eg, extensive blood loss, prolonged surgery with losses from the peritoneum, etc.) or concern about sleep apnea may justify close monitoring in an intensive care unit or similar setting—at least briefly. Later, as the patient recovers, sleep studies may indicate whether apnea is present.
• Document fluid intake and output, especially in the elderly and in women with cardiorespiratory disease.
• Give analgesics in an amount sufficient to control pain and minimize activity that might place excessive tension on the abdominal incision, but also allows the patient to remain alert enough to ambulate effectively and perform pulmonary toileting.
• Begin ambulation on the first postoperative day—or on the evening after surgery, if circumstances permit. This helps clear secretions from the respiratory tract, reduces the risk of thromboembolism, and speeds the return of normal bowel function. Hourly incentive spirometry is also recommended for the first few days after surgery.
• Continue heparin. In patients at moderate or high risk of thromboembolism, continue low-dose heparin until discharge or for 7 days, whichever comes first.
• Keep other physicians involved. If the patient has a significant comorbidity, such as cardiorespiratory disease or uncontrolled diabetes, she should remain under the care of her internist or other primary care provider.
• Closely monitor the surgical wound for early signs of infection, which include inflammation and collections of serous fluid, blood, pus, or a mixture of these. If retention sutures were placed, check them frequently to ensure that they are not cutting into the skin of the abdomen.
• Strongly recommend weight loss. At the time of the last postoperative visit, tell the patient in clear language that obesity is extremely bad for her health and strongly encourage her to lose weight under the supervision of her primary care provider. If she has no such provider, make the appropriate referral.

The authors report no financial relationships relevant to this article.

The adverse consequences of obesity go far beyond aesthetic and psychosocial concerns. Patients who are markedly overweight face a real risk of developing severe health conditions—not just cardiac disease, diabetes mellitus, and hypertension, but also sleep apnea, venous thromboembolism, certain cancers (particularly breast and uterine), and biliary tract disease. Obesity also contributes to menstrual abnormalities and infertility and may complicate pregnancy.

Surgery in these patients poses a number of challenges. Not only does obesity frequently compromise the technical aspects of a procedure, it requires the surgeon to use certain measures in the preoperative and postoperative phases of management, such as counseling the patient extensively about the risks and potential complications she faces, initiating antibiotic prophylaxis, and ensuring early ambulation. These and other measures are especially important when uncontrolled, coexisting disease is present.

Not every obese patient is a significant surgical risk, so care should be individualized and use a team approach involving the gynecologist, anesthesiologist, primary care physician, and other appropriate subspecialists.

This article outlines the parameters of good surgical care in the obese patient, defined here as having a body mass index (BMI) of 30 kg/m² or above, or 35 kg/m² or above for morbid obesity. Whenever possible, we draw our recommendations from the published literature. In the absence of data, we base them on our surgical experience in the obese population.

Risks of surgery

It is imperative for the gynecologic surgeon to discuss the special risks of surgery with the obese patient well in advance of the operation and to formulate a systematic plan for evaluation, utilizing other members of the team when necessary. If the surgeon keeps the following risks in mind and is proactive, complications can be kept to a minimum.

Poor wound healing

Wound healing is a complex process involving several concurrent phases; an abnormality in any phase may impair healing. Those phases are:

• inflammatory phase, in which fluid and cells are released to clean the wound and prepare for the next phase of healing
• fibroplastic (proliferative) phase, in which fibroblasts accumulate and form collagen, the building block of connective tissue. This stage is marked by neovascularization and increased formation of granulation tissue
• wound contraction
• remodeling/maturation, in which new collagen is laid down as old collagen is broken down, resulting in scar formation.

Obese patients possess a thick layer of adipose tissue, which by its nature and location is minimally vascularized. This tissue essentially becomes dead space, an ideal medium for bacterial growth. Many obese patients also have diabetes mellitus, malignancy, or other comorbidity that further impairs healing.

As a result, obese patients are at increased risk of wound complications, breakdown, and subsequent dehiscence and evisceration. This translates into increased febrile morbidity, prolonged hospitalization, and higher cost.

What the data show. A number of studies have documented a higher incidence of wound complications in obese patients. In one retrospective review, Gallup¹ observed an increased risk of wound complications in obese patients, but the incidence diminished after implementation of a protocol of meticulous cleansing, subcutaneous heparin, and modified incision and closure techniques. In a similar retrospective study of 300 obese patients, Pitkin² reported wound complications among approximately one third of patients and postoperative fever among more than three quarters. Surgical-site infections are thought to occur in as many as 5% of patients.

Prophylaxis may be effective in some patients, but can be challenging. It entails meticulous skin cleansing and careful consideration of where the incision is placed, type of closure, use of a drain, and antibiotic administration.

Antibiotic prophylaxis is based on the theory that its presence in host tissues will alter natural defense mechanisms and kill bacteria that inoculate the wound. Because the window of efficacy is narrow, antibiotics should be administered shortly before the time of inoculation (ie, shortly before the time of incision, vaginal entry, etc.). Current guidelines suggest the use of broad-spectrum agents, including a cephalosporin, approximately 60 minutes before the incision. Redosing is recommended for procedures that last longer than 3 hours, as well as for those that involve significant blood loss (>1,500 mL).

For surgical procedures other than hysterectomy and laparotomy, prophylaxis may not be warranted.³ However, when the patient is markedly obese, many surgeons, including me (Dr. Perkins), sometimes opt to give antibiotics anyway—except for laparoscopic procedures—primarily for wound healing.

Compromised operative exposure

One of the main challenges of surgery in the obese is achieving adequate exposure; when it is inadequate, inadvertent injury may occur.

In addition to a thick abdominal wall composed largely of adipose tissue, these patients frequently have significant accumulations of fat in the mesenteries of the bowel, omentum, and pelvic peritoneum. These accumulations make it difficult to navigate around what becomes a narrow operative field.

Exposure can also be limited in vaginal surgery, because many obese women have very large thighs, buttocks, and accumulations of perineal fat.

Because exposure is a key element of successful surgery, modification of the procedure often becomes necessary—eg, focusing on a single area of the operative field at a time.

Use of a special retractor may help. A self-retaining retractor can be extremely useful. The Bookwalter retractor, first described in 1980, is a commonly used, table-fixed system that attaches to the side rail and can be assembled in minutes (FIGURE 1).⁴ The variety of rings and blades allows for excellent exposure. Although several complications have been associated with use of the Bookwalter retractor (primarily colon perforation and neuropathy⁵), they are infrequent and can be minimized by selecting the appropriate blade size and periodically repositioning the blades.

When this or other table-fixed retractors are unavailable, two Balfour retractors, placed at opposite poles of the field to obtain satisfactory exposure, may suffice. With a morbidly obese patient, multiple assistants may still be required to facilitate optimal exposure.

FIGURE 1 A tool to increase exposure

This self-retaining Bookwalter retractor is fixed to the surgical table and features a variety of rings and blades to facilitate exposure.

Thromboembolism

Venous thromboembolism is a major cause of mortality and morbidity in hospitalized patients, causing approximately 60,000 deaths every year.⁶ Obesity increases the risk of deep venous thrombosis in patients undergoing pelvic surgery. Because of their weight—and, often, coexisting conditions such as cardiorespiratory disease—many obese women are inactive or minimally active postoperatively, increasing the risk of thromboembolism, which remains heightened as long as 3 weeks after discharge. Older women are also at high risk, as are those with a malignancy.

Current guidelines call for the application of a pneumatic calf-compression device in the operating room, with removal after the patient is fully ambulatory. I (Dr. Perkins) also advocate simultaneous use of low-dose heparin, which should be given before surgery and continued until discharge.

Although the use of unfractionated heparin in conjunction with spinal or epidural anesthesia is not a major concern, the use of low-molecular-weight heparin warrants consultation with the anesthesiologist. Unfractionated heparin is preferred because it is metabolized much more rapidly than low-molecular weight heparin.⁷ The main concern with use of heparin in this setting (regardless of the patient’s weight) is spinal hematoma formation.

Inadvertent injury

Because exposure tends to be limited in obese patients, there is an ever-present risk of injury to bowel, bladder, ureter, and vascular structures. In obese women with a history of abdominal surgery, adhesions are likely, and the risk of bowel injury is increased. Similarly, in obese patients undergoing a laparoscopic procedure, many surface landmarks and vessels may be hard to discern.

Consider preoperative bowel preparation when there is a high risk of intestinal injury.⁸

Panniculectomy: Old technique with a new surgical purpose

Use a scalpel to incise the skin and delineate the area to be excised. That area typically consists of a large wedge of abdominal skin and subcutaneous fat.

Although the addition of panniculectomy to gynecologic surgery in the morbidly obese patient is a fairly recent strategy to increase exposure, the procedure itself has roots in the 19th century. In 1910, Howard Kelly of The Johns Hopkins Hospital reported a lipectomy that involved excision of a large wedge of abdominal skin and fat,²¹ although indications for that lipectomy appear to have been grounded in cosmesis and personal comfort for the patient.

Technique

Panniculectomy involves excision of a large portion of abdominal skin and subcutaneous fat down to, but not including, the rectus fascia, to gain much greater exposure to the lower abdominal cavity and pelvis.

Once the segment to be excised is delineated, it is mobilized using electrocautery to achieve meticulous hemostasis. After all surgical procedures are completed, the abdominal wall is closed in multiple layers, and drains are placed in the subcutaneous layer. Surgeons who have performed this procedure report significantly increased exposure and access to pelvic structures.

Once the skin is incised, the wedge is mobilized using electrocautery, down to, but not including, the rectus fascia.

Risks

The most important risk is impaired healing of the abdominal wound. One study of this procedure in patients on a gynecologic oncology service noted wound complications in 35% of patients, as well as significant blood loss (up to 1,800 mL in one case).²² Another study by Hopkins and associates,²³ however, reported minimal blood loss and wound complications.

Caveats

The procedure requires an experienced surgeon, particularly if no plastic surgeon is readily available. Also, when counseling the patient about this procedure, it is important to emphasize that its primary indication is to maximize exposure; cosmetic benefits are secondary.

Impaired cardiorespiratory function

Pulmonary function typically is compromised in the markedly obese, with restrictive lung disease and reduced functional residual capacity. If the patient smokes or has chronic obstructive lung disease, her pulmonary function is compromised even further, and her condition should be relayed to the anesthesiologist.

In addition, many obese patients have preexisting heart disease or conditions such as hyperlipidemia that put them at risk for heart disease. When evaluating an obese surgical patient, also ask about less apparent disorders, such as sleep apnea, which, if not addressed, may have grave postoperative consequences.

Preoperative evaluation and preparation

Goal: Assess and minimize risks

This process begins in the office or clinic with a discussion with the patient of any concerns and risks. The importance of early mobilization and ambulation after surgery should be emphasized. Any patient with uncontrolled diabetes or hypertension should continue to be monitored by her primary care physician. A patient who has not seen a physician recently should be assessed by an internist to ensure that no conditions go undetected before surgery.

Routine testing to start, but additional assessment may be justified. An obese patient should undergo the same routine testing as a woman of normal weight, but further testing may be warranted for any coexisting disorder. Because the obese patient may have a restrictive lung pattern by virtue of her body habitus, pulmonary-function testing is unlikely to yield new information and is probably not indicated—unless she smokes or has a history of chronic obstructive pulmonary disease. In that case, tests will clarify the obstructive component and bronchodilator response and are useful in postoperative management. Measurement of arterial blood gases is useful, however, because levels reflect respiratory function on a day-to-day basis.

Additional tests of cardiac status probably are not indicated on the basis of obesity alone. However, if initial tests (eg, the electrocardiogram) and the history suggest compromised cardiac function, two-dimensional echocardiography should be performed to determine the ejection fraction. Any concerns regarding cardiac function should be discussed with the anesthesiologist and cardiologist.

Because compromised pulmonary function is likely, I (Dr. Perkins) instruct each patient on the use of incentive spirometry before she undergoes anesthesia so that she has realistic expectations about the postoperative course. I also administer heparin at least 2 hours before induction (8 hours before induction if unfractionated heparin is used).⁶

If a hysterectomy or prolonged laparotomy is planned, prophylactic antibiotics are recommended.³ Thigh-high compression stockings or a pneumatic calf-compression device should be applied upon arrival in the operating room.

Anesthesia-related issues

Anticipate challenges involving the airway

The anesthesiologist’s primary concern in regard to the obese patient is establishment and maintenance of an airway to promote oxygenation. In morbidly and extremely morbidly obese patients, anatomic factors such as large breasts; a short, thick neck; large tongue; decreased mobility of the cervical spine; limited mouth opening; and greater amount of adipose tissue in the face and cheeks can render mask ventilation and intubation extremely difficult or impossible. Decreased functional residual capacity and tidal volume in the range of closing capacity may lead to extremely rapid oxygen desaturation when the patient is apneic.⁹

If the patient is pregnant, factors such as excess adipose tissue in the face become even more pronounced and increase the potential for catastrophe.

Appreciate mechanical concerns

The morbidly obese patient may exceed the weight limit of the operating table. In addition, placing her in a steep Trendelenburg position or rotating her laterally may compromise the integrity of the bed.

Coexisting disease, such as sleep apnea and acid reflux disease, should also be kept in mind. Compromised respiratory mechanics (eg, restrictive lung pattern) may cause further deterioration and make mechanical ventilation more difficult.

It also may be hard to establish vascular access, necessitating central venous line placement and introducing its associated risks.

Keep the anesthesiologist in the loop

In the postoperative period, obese patients face a heightened risk of complications related to diminished pulmonary function, such as oxygen desaturation, hypoventilation, and airway obstruction, which may lead to atelectasis, pneumonia, and pulmonary edema.^10,11 For these reasons, early consultation with the anesthesiologist is recommended, especially if the initial evaluation suggests potential difficulties in securing the airway. In turn, the anesthesiologist should understand that, in some obese patients, even establishing a surgical airway may be difficult. Regional anesthesia should be considered when feasible.

Antacids and drugs that increase gastric motility have proved to be useful in minimizing aspiration-related risks.^12,13

Surgical technique

Begin abdominal procedures by carefully choosing an incision

Do not base the decision solely on the degree of obesity, but also consider any additional procedures that are planned, such as lymph-node sampling. A vertical incision does permit greater exposure than is afforded by a transverse incision, but in some cases the latter may be more appropriate—even if the patient is morbidly obese.

Do not place the incision below the panniculus, in the crease just above the suprapubic mound, though it may be tempting to do so when the panniculus is large and thick. This area is a warm, moist, anaerobic environment that promotes the proliferation of numerous micro-organisms, creating a bacterial cesspool. It is the worst place to make an incision.

If a transverse incision is selected, place caudal traction on the panniculus (which may be facilitated by applying two towel clips to the tissue fold), and incise through the fold at a point approximately three to four fingerbreadths above the symphysis (FIGURE 2).

If a midline incision is selected, a similar technique is appropriate, with downward traction applied to the panniculus and the incision begun at the lower pole of this fold up to the umbilicus—or through it and above, should more room be required.¹⁴

After incising the superficial fascia, greater exposure may be gained by incising the rectus sheath beneath the pannicular fold and extending it down to the symphysis. After entering the abdominal cavity, the surgeon may encounter a redundant, fat-laden layer of peritoneum. The edges of this tissue may be temporarily sutured to the edges of the skin incision to remove it from the operative field and obtain better visualization.

FIGURE 2 Incision placement can be counterintuitive

Avoid placing the skin incision beneath the panniculus, an anaerobic area ripe for infection. Instead, retract the panniculus caudally and incise the skin above the fold, as shown.

A few remedies can help when exposure is limited

Exposure is one of the most important elements of successful surgery, but it is often restricted when marked obesity is present. Fortunately, numerous adjuncts are available to address this problem, such as the table-fixed retractor systems described earlier in this article, or one or more of the following tactics:

• Do not try to expose the entire pelvic basin. One technique to ease exploration—especially when more than one procedure is planned—is to refrain from exposing the entire pelvic basin at one time. Instead, focus on obtaining adequate visualization in the immediate area and, once work in that area is finished, concentrate on the next.
• Use extra-long instruments in an extremely large patient, especially if she has a “deep” pelvis.
• Abbreviate the procedure, if possible. Because these cases are technically more difficult and frequently involve excessive blood loss, it may be wiser to perform an “incomplete” procedure, such as supracervical hysterectomy instead of total hysterectomy, depending on the indication.¹⁴
• Use a cell-saver blood-collection system if significant blood loss is anticipated. Also remember to give a second dose of prophylactic antibiotic.

Strategies for effective wound closure

The best method of abdominal wound closure has been a subject of debate among both gynecologic and general surgeons. In the obese patient, the key variables are the rather thick subcutaneous fat layer within the abdominal wall and the impact of intra-abdominal pressure on the incision.

What the data show. A number of studies, including one by Montz and colleagues,¹⁵ have demonstrated that the running mass-closure technique using delayed-absorbable or permanent suture is just as effective as interrupted suture placement (eg, Smead-Jones closure) but is faster, with less suture deposited in the wound.

The following considerations may also be helpful:

• Approximate the subcutaneous fascia? There has been some debate about whether the subcutaneous fascia must be approximated. My (Dr. Perkins) personal preference in morbidly obese patients is to place several interrupted sutures to obliterate much of the dead space, facilitate skin closure, and minimize tension on the wound; I have noted no significant increase in wound complications using this technique. Placement of a closed-suction drain (eg, Jackson Pratt, Hemovac) is a good alternative.
• Is a drain useful? Some have questioned whether use of a drain increases the likelihood of wound complications,¹⁶ but this concern is irrelevant because, in most—if not all—cases, the drainage tubing is exteriorized via a separate stab wound remote from the incision.
• Consider retention sutures. A morbidly obese patient may benefit from through-and-through retention sutures using 0 or #1 permanent material along with rubber bolsters to minimize cutting of the suture into the skin, especially if increased intra-abdominal pressure is likely (FIGURE 3).¹⁷ These sutures can be removed on the 10th to 12th postoperative day.

FIGURE 3 Minimize tension on the wound

A morbidly obese patient may benefit from through-and-through retention sutures along with rubber bolsters to minimize cutting of the suture into the skin.

Vaginal surgery does not increase complication rate in the obese