Laparoscopic surgery in the obese: Safe techniques

Gynecologic laparoscopy in the obese? What was once the purview of the very talented or the foolhardy may now be the preferred surgical approach.

Obese women who undergo laparoscopy recover faster, with less pain, fewer wound infections, and shorter hospital stays than with laparotomy. Though it is true that obesity increases operative time and the risk for conversion to laparotomy, little evidence supports the theory that a body mass index (BMI) of 30 kg/m² or higher should exclude laparoscopy.

Preoperative management

Unique elements of the physical

It is important to identify central obesity, which is more difficult to accommodate than distribution around the hips. Unfortunately, the roughly 40 million obese Americans tend to have central fat distribution.^1,2

In central obesity, the subcutaneous tissue is thick, often requiring extra long ports to attain peritoneal access.

The relationship of the umbilicus to the underlying aortic bifurcation also shifts more caudally. This relationship should be noted and planned for before going to the operating room (FIGURE).

Abdominal obesity in particular confers additional risks during all types of surgery: higher rates of atelectasis, thromboembolism, cardiovascular dysfunction, and wound infection.

Closely inspect the skin and panniculus after a routine examination. Obesity predisposes patients to dark, moist, anoxic spaces beneath folds of skin that need to be identified and inspected for evidence of fungal or bacterial infection. To optimize postoperative wound healing, treat any preexisting infections before surgery.

Cigarette smoking further burdens pulmonary mechanics and oxygenation during surgery, so it is important to encourage smokers to kick the habit at least 8 weeks before elective surgery.³

In general, use the history and physical examination to focus on the recognized risk factors of obesity, with specific emphasis on hypertension, coronary artery disease, arrhythmia, pulmonary obstructive disease, peripheral vascular disease, diabetes, gastric reflux, and arthritis.⁴

Special tests and laboratory studies

EKG and chest x-ray. In morbidly obese patients (BMI >40), preoperative evaluation includes an electrocardiogram (EKG) and chest x-ray to identify any cardiomegaly, arrhythmias, and occult ischemia or conduction blockage.

Arterial blood gas sampling. Given the higher risk of postoperative thrombotic events in obese patients, it can be helpful to assess preoperative oxygenation and ventilation/perfusion status via arterial blood gas sampling. The obese may have elevated baseline Aa gradients, which, if not noted prior to surgery, can confuse later management of suspected pulmonary emboli.

During testing, assess venous access and counsel the patient if central venous line placement may be possible at surgery. Though central line placement is not routinely recommended, it may be warranted in patients with particularly difficult peripheral venous access.

Skip pulmonary function testing because the results rarely change surgical management. We consider its routine use to be wasteful.

Laboratory evaluation should include betahuman chorionic gonadotropin (in premenopausal patients), complete blood count, electrolytes, glucose, renal function, and type and screen.

Spell out risks at informed consent

The preoperative appointment is your chance to answer questions the patient may have and clearly delineate the risks and benefits of surgery. During this discussion, spell out the increased risks of conversion to laparotomy, prolonged anesthesia, postoperative thrombosis, wound infection, and pulmonary complications, and make sure all are listed on the written consent form.

Operative management

Prophylactic measures

Complete bowel preparation is recommended the evening prior to surgery, since intraabdominal visualization can be difficult and conversion to laparotomy may be necessary. Bowel prep decompresses the lumen, improving visualization and the outcome of any bowel injury.

Preoperative histamine receptor blockade is recommended for optimal results, since higher body mass can lead to increases in low pH gastric volume and difficulties with intubation.⁵ A typical regimen is 50 mg intravenous (IV) ranitidine 20 minutes prior to surgery.

Beta blockade. All patients with hypertension or a history of coronary artery disease should receive preoperative beta blockade, assuming there are no contraindications such as reactive airway disease or cardiac conduction block. Atenolol 10 mg IV 20 minutes prior to surgery is a standard initial dose. All patients already taking beta blockers should simply continue their home regimen through the day of surgery with small sips of water.

 

Antibiotics. The high rate of postoperative wound infection in obese patients makes preoperative antibiotic treatment logical. Although we were unable to find any studies demonstrating the benefit of routine antibiotic prophylaxis in obese patients undergoing laparoscopy, data do show a benefit when laparotomy is performed.

If no allergies or contraindications exist, give 1 to 2 g of a first-or second-generation cephalosporin intravenously 20 to 30 minutes prior to anesthesia induction.

Sequential compression devices. Since both obesity and gynecologic surgery are risk factors for deep venous thrombosis, use large sequential compression devices on the lower extremities, beginning before induction of anesthesia.

Position the patient for optimal access

Only 1 recent publication explores this issue in obese laparoscopy patients. Lamvu et al⁵ advocate the armstucked (“military”), low lithotomy position, with liberal padding on the legs and arms and a gel pad under the lower back. They also recommend stationary shoulder blocks to help maintain positioning in the Trendelenburg (head down) position, and they use clamps, gauze, weights, and tape to maintain the panniculus in its caudad position.

Novel technique realigns umbilical axis. We, too, use padding liberally on all pressure points, but do not weight the panniculus. In fact, we prefer its cephalad migration in the Trendelenburg position. Pelosi and Pelosi⁶ describe a useful technique to realign the umbilical axis cephalad before placing the first trocar (FIGURE). Once the Trendelenburg position is attained (after initial trocar placement), this cephalad position eases ancillary port placement.

Tucking 1 arm facilitates surgery, anesthesia access. Tucking both arms is ideal but not always feasible. It is especially problematic when adipose tissue surrounding the biceps makes the military position impossible. Further, anesthesiologists may be unwilling to abandon access to the peripheral intravenous site, since placement and emergency replacement can be difficult.

Central venous access is always an option but is not without risk and should be avoided, if possible. A creative alternative: Tuck the nonaccessed arm at the patient’s side and place the other arm over the chest. Maintain this position by tucking a sheet over the chest. This gives the anesthesia team access to 1 arm while facilitating ideal surgeon positioning.

Do not use shoulder blocks when the patient’s arms are extended, as this increases the risk of brachial plexus injury should the patient slide.

Success hinges on port placement, pneumoperitoneum

The success or failure of most laparoscopic surgeries is determined in the initial minutes during placement of the operative ports. This is especially true in obese patients. No single variable is more important to successful laparoscopy in obese patients than the establishment of pneumoperitoneum.

 

Entry variables of 3 body types. Obesity increases the distance between skin and fascia, and can increase the distance between fascia and peritoneum. The difficulty of placing the Veress needle or trocar into the peritoneal cavity increases with this distance. Preperitoneal insufflation of gas exacerbates the problem. In addition, dissection to the level of the fascia for an open (Hasson) approach sometimes requires incision extension and increases the risk of postoperative wound infection.

Obesity also changes the relationship of the umbilicus to the aortic bifurcation. Utilizing computed tomography, Hurd et al⁷ demonstrated that the umbilicus migrates caudally in relation to the aortic bifurcation as the BMI increases. In nonobese patients (BMI 30) patients, the umbilicus had a median location 2.4 and 2.9 cm caudal to the aortic bifurcation, respectively. However, in both groups, the umbilicus was directly over the aortic bifurcation in 30% of patients.

The same group of researchers, again using computed tomography, demonstrated that the distance between the umbilicus and peritoneum at a 45° angle from the umbilicus into the pelvis, in both nonobese and overweight patients, was only 2 cm. In obese patients, this distance increased to a median of 12 cm. Hurd et al⁸ also noted that the distance between the umbilicus and the underlying vessels was only 6 cm at a 90° angle in nonobese patients, but averaged 13 cm in obese patients.

To optimize intraperitoneal Veress needle and trocar placement while minimizing risk to the underlying vasculature, Hurd and colleagues recommend a 45° angle from the umbilicus toward the pelvis in nonobese patients and a 90° approach in obese patients. In overweight patients, the approach should range between 45° and 90° (TABLE 1).

TABLE 1

Instrument placement in laparoscopy: Anatomic distances and suggested angles

	DISTANCE FROM THE UMBILICUS (CM)
GROUP	TO BIFURCATION	TO PERITONEUM	TO VESSELS AT 90°	RECOMMENDED PLACEMENT ANGLE
Nonobese (BMI	0.4 ± 1.6	2 ± 2	6 ± 3	45°
Overweight (BMI 25–30)	2.4 ± 1.9	2 ± 1	10 ± 2	45–90°
Obese (BMI >30)	2.9 ± 2.5	12 (median)	13 ± 4	90°
Data are presented as mean ± standard deviation, median, or degrees from horizontal
Source: Hurd WW, et al 7

Gaining intraperitoneal access: Which approach is best?

A number of studies and case series have explored the fundamental difficulty of gaining intraperitoneal access. Pasic et al⁹ retrospectively analyzed outcomes in separate cohorts of obese and nonobese patients, focusing on 4 entry approaches:

• transumbilical open,
  
• transumbilical Veress needle placement,
  
• subcostal Veress needle placement in the midclavicular line of the left upper quadrant, and
  
• transuterine Veress needle placement.
  

The only group that demonstrated a significantly higher failure rate for obese patients was the open approach. Ultimately, the authors recommended using the Veress needle in the left upper quadrant or via the uterus for obese patients.

In contrast, the Pelosi case series of 67 consecutive obese patients⁶ reported no failures with a transumbilical open approach after realignment of the umbilical access. This entailed assessing the position of the umbilicus in relation to a line drawn between the 2 anterior superior iliac spines. The umbilicus then was repositioned 8 cm above this line in its “anatomical” position prior to initiating open dissection (FIGURE).

After the open trocar was inserted through the fascia and peritoneum and the patient was placed in the Trendelenburg position, the panniculus maintained its orientation. Pelosi and Pelosi concluded that this realignment of the umbilical axis decreases the depth of open dissection and avoids inadvertent placement of a trocar through both sides of the panniculus.

A prospective, randomized study¹⁰ comparing transumbilical and transuterine Veress needle placement in obese patients found the latter approach useful, but recorded a single case of postoperative chlamydial pelvic inflammatory disease. Thus, preoperative testing for sexually transmitted disease is recommended for this approach.

Avoid dogmatic reliance on a single approach

These studies demonstrate a fundamental surgical truism: Sound physiologic and anatomic knowledge, combined with versatility and a grasp of multiple approaches to any problem, are ultimately more successful than unyielding reliance on a single approach. Aim for prudent use of open or closed laparoscopy in a variety of locations, taking into account the patient’s surgical history, distribution of fat, and umbilical displacement.

After achieving pneumoperitoneum

Place a salinefilled spinal needle into the peritoneal cavity on suction to establish abdominal wall thickness. In this way, trocars of appropriate length can be selected.

Some authorities advocate insufflation to a high intraperitoneal pressure (25 to 30mm Hg) prior to placing the initial umbilical trocar if a closed technique is being used.¹¹ This further elevates the abdominal wall and decreases the risk of preperitoneal trocar placement. After successful trocar placement, immediately reduce intraabdominal pressure to 15 mm Hg to avoid pulmonary compromise, excessive catecholamine release, and subcutaneous emphysema.

 

Techniques to enhance visualization

Excess adipose tissue occupies the pericolic, omental, mesenteric, and retroperitoneal spaces in obese patients, obscuring visualization of intraperitoneal and retroperitoneal structures.

Preoperative mechanical bowel preparation can deflate the bowel and enhance visualization (TABLE 2). At times, an extra ancillary trocar for placement of a bowel retractor also can improve visualization.

In the morbidly obese, insufflation pressure of 15 mm Hg will sometimes produce poor visualization. Obese patients generally tolerate this pressure reasonably well, but increasing it to improve visualization can make adequate oxygenation impossible.

Gasless laparoscopy—in which a mechanical retractor is attached from the table to the patient’s anterior abdominal wall—may help improve pulmonary mechanical parameters. Unfortunately, this technique often produces poorer visualization than insufflation at normal pressure.

A new technique that combines approaches may help avoid the need to convert to laparotomy.¹² In this “Foley lap lift,” a 14-French Foley catheter is passed through the anterior abdominal wall, and the balloon is inflated. The catheter then is elevated and clamped to a retractor holder attached to the angled foot of the bed. This upward traction with continuous gas flow at normal pressure improves visualization without pulmonary compromise.

TABLE 2

Techniques to enhance visualization

Preoperative mechanical bowel preparation Ancillary trocar for placement of bowel retractor Gasless laparoscopy* Foley lap lift*
*See page 70 for details

Close port sites at the fascial level

The risk of bowel herniation through a trocar site is higher in obese patients than the general population because of the greater intraabdominal pressures. Increases in atelectasis from diminished functional residual capacity also predispose the obese patient to postoperative pulmonary complications and can lead to recurrent Valsalva (cough) and subsequent bowel herniation.

Given these risks, it is imperative that all port sites 10 mm or larger be closed at the fascial level. Unfortunately, the distance from the anterior abdominal wall to the fascia underlying these sites makes direct visualization and closure almost impossible.

Fortunately, several fascial closure devices are available and are reasonably inexpensive and easy to use. When using them, be sure to maintain the other port sites, as closure requires direct visualization and a second instrument.

Postoperative strategies

Successful postoperative care builds on preoperative and intraoperative tactics.

Perform aggressive pulmonary toilet

With intraoperative decreases in functional residual capacity, postoperative atelectasis is likely to be profound, with a potential for ventilation/perfusion mismatch and hypoxemia.

Aggressive pulmonary toilet including regular incentive spirometry and deep breathing and coughing exercises is important to reinflate dependent lung regions. Pulse oximetry with sufficient supplementary oxygen also is important to maintain adequate saturation.

Encourage early ambulation

This requires adequate but not oversedating analgesia, early catheter removal, and a motivated nursing staff.

Early ambulation is associated with fewer episodes of deep venous thrombosis, pulmonary complications, and ileus, and also eases pain management.

Continue thrombosis prophylaxis with sequential compression devices, subcutaneous heparin, or both, until the patient is spending most of her time out of bed.

Dr. Robinson reports no relevant financial relationships.

Dr. Isaacson serves on the speakers bureau for Karl Storz Endoscopy.

Gynecologic laparoscopy in the obese? What was once the purview of the very talented or the foolhardy may now be the preferred surgical approach.

Obese women who undergo laparoscopy recover faster, with less pain, fewer wound infections, and shorter hospital stays than with laparotomy. Though it is true that obesity increases operative time and the risk for conversion to laparotomy, little evidence supports the theory that a body mass index (BMI) of 30 kg/m² or higher should exclude laparoscopy.

Preoperative management

Unique elements of the physical

It is important to identify central obesity, which is more difficult to accommodate than distribution around the hips. Unfortunately, the roughly 40 million obese Americans tend to have central fat distribution.^1,2

In central obesity, the subcutaneous tissue is thick, often requiring extra long ports to attain peritoneal access.

The relationship of the umbilicus to the underlying aortic bifurcation also shifts more caudally. This relationship should be noted and planned for before going to the operating room (FIGURE).

Abdominal obesity in particular confers additional risks during all types of surgery: higher rates of atelectasis, thromboembolism, cardiovascular dysfunction, and wound infection.

Closely inspect the skin and panniculus after a routine examination. Obesity predisposes patients to dark, moist, anoxic spaces beneath folds of skin that need to be identified and inspected for evidence of fungal or bacterial infection. To optimize postoperative wound healing, treat any preexisting infections before surgery.

Cigarette smoking further burdens pulmonary mechanics and oxygenation during surgery, so it is important to encourage smokers to kick the habit at least 8 weeks before elective surgery.³

In general, use the history and physical examination to focus on the recognized risk factors of obesity, with specific emphasis on hypertension, coronary artery disease, arrhythmia, pulmonary obstructive disease, peripheral vascular disease, diabetes, gastric reflux, and arthritis.⁴

Special tests and laboratory studies

EKG and chest x-ray. In morbidly obese patients (BMI >40), preoperative evaluation includes an electrocardiogram (EKG) and chest x-ray to identify any cardiomegaly, arrhythmias, and occult ischemia or conduction blockage.

Arterial blood gas sampling. Given the higher risk of postoperative thrombotic events in obese patients, it can be helpful to assess preoperative oxygenation and ventilation/perfusion status via arterial blood gas sampling. The obese may have elevated baseline Aa gradients, which, if not noted prior to surgery, can confuse later management of suspected pulmonary emboli.

During testing, assess venous access and counsel the patient if central venous line placement may be possible at surgery. Though central line placement is not routinely recommended, it may be warranted in patients with particularly difficult peripheral venous access.

Skip pulmonary function testing because the results rarely change surgical management. We consider its routine use to be wasteful.

Laboratory evaluation should include betahuman chorionic gonadotropin (in premenopausal patients), complete blood count, electrolytes, glucose, renal function, and type and screen.

Spell out risks at informed consent

The preoperative appointment is your chance to answer questions the patient may have and clearly delineate the risks and benefits of surgery. During this discussion, spell out the increased risks of conversion to laparotomy, prolonged anesthesia, postoperative thrombosis, wound infection, and pulmonary complications, and make sure all are listed on the written consent form.

Operative management

Prophylactic measures

Complete bowel preparation is recommended the evening prior to surgery, since intraabdominal visualization can be difficult and conversion to laparotomy may be necessary. Bowel prep decompresses the lumen, improving visualization and the outcome of any bowel injury.

Preoperative histamine receptor blockade is recommended for optimal results, since higher body mass can lead to increases in low pH gastric volume and difficulties with intubation.⁵ A typical regimen is 50 mg intravenous (IV) ranitidine 20 minutes prior to surgery.

Beta blockade. All patients with hypertension or a history of coronary artery disease should receive preoperative beta blockade, assuming there are no contraindications such as reactive airway disease or cardiac conduction block. Atenolol 10 mg IV 20 minutes prior to surgery is a standard initial dose. All patients already taking beta blockers should simply continue their home regimen through the day of surgery with small sips of water.

 

Antibiotics. The high rate of postoperative wound infection in obese patients makes preoperative antibiotic treatment logical. Although we were unable to find any studies demonstrating the benefit of routine antibiotic prophylaxis in obese patients undergoing laparoscopy, data do show a benefit when laparotomy is performed.

If no allergies or contraindications exist, give 1 to 2 g of a first-or second-generation cephalosporin intravenously 20 to 30 minutes prior to anesthesia induction.

Sequential compression devices. Since both obesity and gynecologic surgery are risk factors for deep venous thrombosis, use large sequential compression devices on the lower extremities, beginning before induction of anesthesia.

Position the patient for optimal access

Only 1 recent publication explores this issue in obese laparoscopy patients. Lamvu et al⁵ advocate the armstucked (“military”), low lithotomy position, with liberal padding on the legs and arms and a gel pad under the lower back. They also recommend stationary shoulder blocks to help maintain positioning in the Trendelenburg (head down) position, and they use clamps, gauze, weights, and tape to maintain the panniculus in its caudad position.

Novel technique realigns umbilical axis. We, too, use padding liberally on all pressure points, but do not weight the panniculus. In fact, we prefer its cephalad migration in the Trendelenburg position. Pelosi and Pelosi⁶ describe a useful technique to realign the umbilical axis cephalad before placing the first trocar (FIGURE). Once the Trendelenburg position is attained (after initial trocar placement), this cephalad position eases ancillary port placement.

Tucking 1 arm facilitates surgery, anesthesia access. Tucking both arms is ideal but not always feasible. It is especially problematic when adipose tissue surrounding the biceps makes the military position impossible. Further, anesthesiologists may be unwilling to abandon access to the peripheral intravenous site, since placement and emergency replacement can be difficult.

Central venous access is always an option but is not without risk and should be avoided, if possible. A creative alternative: Tuck the nonaccessed arm at the patient’s side and place the other arm over the chest. Maintain this position by tucking a sheet over the chest. This gives the anesthesia team access to 1 arm while facilitating ideal surgeon positioning.

Do not use shoulder blocks when the patient’s arms are extended, as this increases the risk of brachial plexus injury should the patient slide.

Success hinges on port placement, pneumoperitoneum

The success or failure of most laparoscopic surgeries is determined in the initial minutes during placement of the operative ports. This is especially true in obese patients. No single variable is more important to successful laparoscopy in obese patients than the establishment of pneumoperitoneum.

 

Entry variables of 3 body types. Obesity increases the distance between skin and fascia, and can increase the distance between fascia and peritoneum. The difficulty of placing the Veress needle or trocar into the peritoneal cavity increases with this distance. Preperitoneal insufflation of gas exacerbates the problem. In addition, dissection to the level of the fascia for an open (Hasson) approach sometimes requires incision extension and increases the risk of postoperative wound infection.

Obesity also changes the relationship of the umbilicus to the aortic bifurcation. Utilizing computed tomography, Hurd et al⁷ demonstrated that the umbilicus migrates caudally in relation to the aortic bifurcation as the BMI increases. In nonobese patients (BMI 30) patients, the umbilicus had a median location 2.4 and 2.9 cm caudal to the aortic bifurcation, respectively. However, in both groups, the umbilicus was directly over the aortic bifurcation in 30% of patients.

The same group of researchers, again using computed tomography, demonstrated that the distance between the umbilicus and peritoneum at a 45° angle from the umbilicus into the pelvis, in both nonobese and overweight patients, was only 2 cm. In obese patients, this distance increased to a median of 12 cm. Hurd et al⁸ also noted that the distance between the umbilicus and the underlying vessels was only 6 cm at a 90° angle in nonobese patients, but averaged 13 cm in obese patients.

To optimize intraperitoneal Veress needle and trocar placement while minimizing risk to the underlying vasculature, Hurd and colleagues recommend a 45° angle from the umbilicus toward the pelvis in nonobese patients and a 90° approach in obese patients. In overweight patients, the approach should range between 45° and 90° (TABLE 1).

TABLE 1

Instrument placement in laparoscopy: Anatomic distances and suggested angles

	DISTANCE FROM THE UMBILICUS (CM)
GROUP	TO BIFURCATION	TO PERITONEUM	TO VESSELS AT 90°	RECOMMENDED PLACEMENT ANGLE
Nonobese (BMI	0.4 ± 1.6	2 ± 2	6 ± 3	45°
Overweight (BMI 25–30)	2.4 ± 1.9	2 ± 1	10 ± 2	45–90°
Obese (BMI >30)	2.9 ± 2.5	12 (median)	13 ± 4	90°
Data are presented as mean ± standard deviation, median, or degrees from horizontal
Source: Hurd WW, et al 7

Gaining intraperitoneal access: Which approach is best?

A number of studies and case series have explored the fundamental difficulty of gaining intraperitoneal access. Pasic et al⁹ retrospectively analyzed outcomes in separate cohorts of obese and nonobese patients, focusing on 4 entry approaches:

• transumbilical open,
  
• transumbilical Veress needle placement,
  
• subcostal Veress needle placement in the midclavicular line of the left upper quadrant, and
  
• transuterine Veress needle placement.
  

The only group that demonstrated a significantly higher failure rate for obese patients was the open approach. Ultimately, the authors recommended using the Veress needle in the left upper quadrant or via the uterus for obese patients.

In contrast, the Pelosi case series of 67 consecutive obese patients⁶ reported no failures with a transumbilical open approach after realignment of the umbilical access. This entailed assessing the position of the umbilicus in relation to a line drawn between the 2 anterior superior iliac spines. The umbilicus then was repositioned 8 cm above this line in its “anatomical” position prior to initiating open dissection (FIGURE).

After the open trocar was inserted through the fascia and peritoneum and the patient was placed in the Trendelenburg position, the panniculus maintained its orientation. Pelosi and Pelosi concluded that this realignment of the umbilical axis decreases the depth of open dissection and avoids inadvertent placement of a trocar through both sides of the panniculus.

A prospective, randomized study¹⁰ comparing transumbilical and transuterine Veress needle placement in obese patients found the latter approach useful, but recorded a single case of postoperative chlamydial pelvic inflammatory disease. Thus, preoperative testing for sexually transmitted disease is recommended for this approach.

Avoid dogmatic reliance on a single approach

These studies demonstrate a fundamental surgical truism: Sound physiologic and anatomic knowledge, combined with versatility and a grasp of multiple approaches to any problem, are ultimately more successful than unyielding reliance on a single approach. Aim for prudent use of open or closed laparoscopy in a variety of locations, taking into account the patient’s surgical history, distribution of fat, and umbilical displacement.

After achieving pneumoperitoneum

Place a salinefilled spinal needle into the peritoneal cavity on suction to establish abdominal wall thickness. In this way, trocars of appropriate length can be selected.

Some authorities advocate insufflation to a high intraperitoneal pressure (25 to 30mm Hg) prior to placing the initial umbilical trocar if a closed technique is being used.¹¹ This further elevates the abdominal wall and decreases the risk of preperitoneal trocar placement. After successful trocar placement, immediately reduce intraabdominal pressure to 15 mm Hg to avoid pulmonary compromise, excessive catecholamine release, and subcutaneous emphysema.

 

Techniques to enhance visualization

Excess adipose tissue occupies the pericolic, omental, mesenteric, and retroperitoneal spaces in obese patients, obscuring visualization of intraperitoneal and retroperitoneal structures.

Preoperative mechanical bowel preparation can deflate the bowel and enhance visualization (TABLE 2). At times, an extra ancillary trocar for placement of a bowel retractor also can improve visualization.

In the morbidly obese, insufflation pressure of 15 mm Hg will sometimes produce poor visualization. Obese patients generally tolerate this pressure reasonably well, but increasing it to improve visualization can make adequate oxygenation impossible.

Gasless laparoscopy—in which a mechanical retractor is attached from the table to the patient’s anterior abdominal wall—may help improve pulmonary mechanical parameters. Unfortunately, this technique often produces poorer visualization than insufflation at normal pressure.

A new technique that combines approaches may help avoid the need to convert to laparotomy.¹² In this “Foley lap lift,” a 14-French Foley catheter is passed through the anterior abdominal wall, and the balloon is inflated. The catheter then is elevated and clamped to a retractor holder attached to the angled foot of the bed. This upward traction with continuous gas flow at normal pressure improves visualization without pulmonary compromise.

TABLE 2

Techniques to enhance visualization

Preoperative mechanical bowel preparation Ancillary trocar for placement of bowel retractor Gasless laparoscopy* Foley lap lift*
*See page 70 for details

Close port sites at the fascial level

The risk of bowel herniation through a trocar site is higher in obese patients than the general population because of the greater intraabdominal pressures. Increases in atelectasis from diminished functional residual capacity also predispose the obese patient to postoperative pulmonary complications and can lead to recurrent Valsalva (cough) and subsequent bowel herniation.

Given these risks, it is imperative that all port sites 10 mm or larger be closed at the fascial level. Unfortunately, the distance from the anterior abdominal wall to the fascia underlying these sites makes direct visualization and closure almost impossible.

Fortunately, several fascial closure devices are available and are reasonably inexpensive and easy to use. When using them, be sure to maintain the other port sites, as closure requires direct visualization and a second instrument.

Postoperative strategies

Successful postoperative care builds on preoperative and intraoperative tactics.

Perform aggressive pulmonary toilet

With intraoperative decreases in functional residual capacity, postoperative atelectasis is likely to be profound, with a potential for ventilation/perfusion mismatch and hypoxemia.

Aggressive pulmonary toilet including regular incentive spirometry and deep breathing and coughing exercises is important to reinflate dependent lung regions. Pulse oximetry with sufficient supplementary oxygen also is important to maintain adequate saturation.

Encourage early ambulation

This requires adequate but not oversedating analgesia, early catheter removal, and a motivated nursing staff.

Early ambulation is associated with fewer episodes of deep venous thrombosis, pulmonary complications, and ileus, and also eases pain management.

Continue thrombosis prophylaxis with sequential compression devices, subcutaneous heparin, or both, until the patient is spending most of her time out of bed.

Dr. Robinson reports no relevant financial relationships.

Dr. Isaacson serves on the speakers bureau for Karl Storz Endoscopy.

Gynecologic laparoscopy in the obese? What was once the purview of the very talented or the foolhardy may now be the preferred surgical approach.

Obese women who undergo laparoscopy recover faster, with less pain, fewer wound infections, and shorter hospital stays than with laparotomy. Though it is true that obesity increases operative time and the risk for conversion to laparotomy, little evidence supports the theory that a body mass index (BMI) of 30 kg/m² or higher should exclude laparoscopy.

Preoperative management

Unique elements of the physical

It is important to identify central obesity, which is more difficult to accommodate than distribution around the hips. Unfortunately, the roughly 40 million obese Americans tend to have central fat distribution.^1,2

In central obesity, the subcutaneous tissue is thick, often requiring extra long ports to attain peritoneal access.

The relationship of the umbilicus to the underlying aortic bifurcation also shifts more caudally. This relationship should be noted and planned for before going to the operating room (FIGURE).

Abdominal obesity in particular confers additional risks during all types of surgery: higher rates of atelectasis, thromboembolism, cardiovascular dysfunction, and wound infection.

Closely inspect the skin and panniculus after a routine examination. Obesity predisposes patients to dark, moist, anoxic spaces beneath folds of skin that need to be identified and inspected for evidence of fungal or bacterial infection. To optimize postoperative wound healing, treat any preexisting infections before surgery.

Cigarette smoking further burdens pulmonary mechanics and oxygenation during surgery, so it is important to encourage smokers to kick the habit at least 8 weeks before elective surgery.³

In general, use the history and physical examination to focus on the recognized risk factors of obesity, with specific emphasis on hypertension, coronary artery disease, arrhythmia, pulmonary obstructive disease, peripheral vascular disease, diabetes, gastric reflux, and arthritis.⁴

Special tests and laboratory studies

EKG and chest x-ray. In morbidly obese patients (BMI >40), preoperative evaluation includes an electrocardiogram (EKG) and chest x-ray to identify any cardiomegaly, arrhythmias, and occult ischemia or conduction blockage.

Arterial blood gas sampling. Given the higher risk of postoperative thrombotic events in obese patients, it can be helpful to assess preoperative oxygenation and ventilation/perfusion status via arterial blood gas sampling. The obese may have elevated baseline Aa gradients, which, if not noted prior to surgery, can confuse later management of suspected pulmonary emboli.

During testing, assess venous access and counsel the patient if central venous line placement may be possible at surgery. Though central line placement is not routinely recommended, it may be warranted in patients with particularly difficult peripheral venous access.

Skip pulmonary function testing because the results rarely change surgical management. We consider its routine use to be wasteful.

Laboratory evaluation should include betahuman chorionic gonadotropin (in premenopausal patients), complete blood count, electrolytes, glucose, renal function, and type and screen.

Spell out risks at informed consent

The preoperative appointment is your chance to answer questions the patient may have and clearly delineate the risks and benefits of surgery. During this discussion, spell out the increased risks of conversion to laparotomy, prolonged anesthesia, postoperative thrombosis, wound infection, and pulmonary complications, and make sure all are listed on the written consent form.

Operative management

Prophylactic measures

Complete bowel preparation is recommended the evening prior to surgery, since intraabdominal visualization can be difficult and conversion to laparotomy may be necessary. Bowel prep decompresses the lumen, improving visualization and the outcome of any bowel injury.

Preoperative histamine receptor blockade is recommended for optimal results, since higher body mass can lead to increases in low pH gastric volume and difficulties with intubation.⁵ A typical regimen is 50 mg intravenous (IV) ranitidine 20 minutes prior to surgery.

Beta blockade. All patients with hypertension or a history of coronary artery disease should receive preoperative beta blockade, assuming there are no contraindications such as reactive airway disease or cardiac conduction block. Atenolol 10 mg IV 20 minutes prior to surgery is a standard initial dose. All patients already taking beta blockers should simply continue their home regimen through the day of surgery with small sips of water.

 

Antibiotics. The high rate of postoperative wound infection in obese patients makes preoperative antibiotic treatment logical. Although we were unable to find any studies demonstrating the benefit of routine antibiotic prophylaxis in obese patients undergoing laparoscopy, data do show a benefit when laparotomy is performed.

If no allergies or contraindications exist, give 1 to 2 g of a first-or second-generation cephalosporin intravenously 20 to 30 minutes prior to anesthesia induction.

Sequential compression devices. Since both obesity and gynecologic surgery are risk factors for deep venous thrombosis, use large sequential compression devices on the lower extremities, beginning before induction of anesthesia.

Position the patient for optimal access

Only 1 recent publication explores this issue in obese laparoscopy patients. Lamvu et al⁵ advocate the armstucked (“military”), low lithotomy position, with liberal padding on the legs and arms and a gel pad under the lower back. They also recommend stationary shoulder blocks to help maintain positioning in the Trendelenburg (head down) position, and they use clamps, gauze, weights, and tape to maintain the panniculus in its caudad position.

Novel technique realigns umbilical axis. We, too, use padding liberally on all pressure points, but do not weight the panniculus. In fact, we prefer its cephalad migration in the Trendelenburg position. Pelosi and Pelosi⁶ describe a useful technique to realign the umbilical axis cephalad before placing the first trocar (FIGURE). Once the Trendelenburg position is attained (after initial trocar placement), this cephalad position eases ancillary port placement.

Tucking 1 arm facilitates surgery, anesthesia access. Tucking both arms is ideal but not always feasible. It is especially problematic when adipose tissue surrounding the biceps makes the military position impossible. Further, anesthesiologists may be unwilling to abandon access to the peripheral intravenous site, since placement and emergency replacement can be difficult.

Central venous access is always an option but is not without risk and should be avoided, if possible. A creative alternative: Tuck the nonaccessed arm at the patient’s side and place the other arm over the chest. Maintain this position by tucking a sheet over the chest. This gives the anesthesia team access to 1 arm while facilitating ideal surgeon positioning.

Do not use shoulder blocks when the patient’s arms are extended, as this increases the risk of brachial plexus injury should the patient slide.

Success hinges on port placement, pneumoperitoneum

The success or failure of most laparoscopic surgeries is determined in the initial minutes during placement of the operative ports. This is especially true in obese patients. No single variable is more important to successful laparoscopy in obese patients than the establishment of pneumoperitoneum.

 

Entry variables of 3 body types. Obesity increases the distance between skin and fascia, and can increase the distance between fascia and peritoneum. The difficulty of placing the Veress needle or trocar into the peritoneal cavity increases with this distance. Preperitoneal insufflation of gas exacerbates the problem. In addition, dissection to the level of the fascia for an open (Hasson) approach sometimes requires incision extension and increases the risk of postoperative wound infection.

Obesity also changes the relationship of the umbilicus to the aortic bifurcation. Utilizing computed tomography, Hurd et al⁷ demonstrated that the umbilicus migrates caudally in relation to the aortic bifurcation as the BMI increases. In nonobese patients (BMI 30) patients, the umbilicus had a median location 2.4 and 2.9 cm caudal to the aortic bifurcation, respectively. However, in both groups, the umbilicus was directly over the aortic bifurcation in 30% of patients.

The same group of researchers, again using computed tomography, demonstrated that the distance between the umbilicus and peritoneum at a 45° angle from the umbilicus into the pelvis, in both nonobese and overweight patients, was only 2 cm. In obese patients, this distance increased to a median of 12 cm. Hurd et al⁸ also noted that the distance between the umbilicus and the underlying vessels was only 6 cm at a 90° angle in nonobese patients, but averaged 13 cm in obese patients.

To optimize intraperitoneal Veress needle and trocar placement while minimizing risk to the underlying vasculature, Hurd and colleagues recommend a 45° angle from the umbilicus toward the pelvis in nonobese patients and a 90° approach in obese patients. In overweight patients, the approach should range between 45° and 90° (TABLE 1).

TABLE 1

Instrument placement in laparoscopy: Anatomic distances and suggested angles

	DISTANCE FROM THE UMBILICUS (CM)
GROUP	TO BIFURCATION	TO PERITONEUM	TO VESSELS AT 90°	RECOMMENDED PLACEMENT ANGLE
Nonobese (BMI	0.4 ± 1.6	2 ± 2	6 ± 3	45°
Overweight (BMI 25–30)	2.4 ± 1.9	2 ± 1	10 ± 2	45–90°
Obese (BMI >30)	2.9 ± 2.5	12 (median)	13 ± 4	90°
Data are presented as mean ± standard deviation, median, or degrees from horizontal
Source: Hurd WW, et al 7

Gaining intraperitoneal access: Which approach is best?

A number of studies and case series have explored the fundamental difficulty of gaining intraperitoneal access. Pasic et al⁹ retrospectively analyzed outcomes in separate cohorts of obese and nonobese patients, focusing on 4 entry approaches:

• transumbilical open,
  
• transumbilical Veress needle placement,
  
• subcostal Veress needle placement in the midclavicular line of the left upper quadrant, and
  
• transuterine Veress needle placement.
  

The only group that demonstrated a significantly higher failure rate for obese patients was the open approach. Ultimately, the authors recommended using the Veress needle in the left upper quadrant or via the uterus for obese patients.

In contrast, the Pelosi case series of 67 consecutive obese patients⁶ reported no failures with a transumbilical open approach after realignment of the umbilical access. This entailed assessing the position of the umbilicus in relation to a line drawn between the 2 anterior superior iliac spines. The umbilicus then was repositioned 8 cm above this line in its “anatomical” position prior to initiating open dissection (FIGURE).

After the open trocar was inserted through the fascia and peritoneum and the patient was placed in the Trendelenburg position, the panniculus maintained its orientation. Pelosi and Pelosi concluded that this realignment of the umbilical axis decreases the depth of open dissection and avoids inadvertent placement of a trocar through both sides of the panniculus.

A prospective, randomized study¹⁰ comparing transumbilical and transuterine Veress needle placement in obese patients found the latter approach useful, but recorded a single case of postoperative chlamydial pelvic inflammatory disease. Thus, preoperative testing for sexually transmitted disease is recommended for this approach.

Avoid dogmatic reliance on a single approach

These studies demonstrate a fundamental surgical truism: Sound physiologic and anatomic knowledge, combined with versatility and a grasp of multiple approaches to any problem, are ultimately more successful than unyielding reliance on a single approach. Aim for prudent use of open or closed laparoscopy in a variety of locations, taking into account the patient’s surgical history, distribution of fat, and umbilical displacement.

After achieving pneumoperitoneum

Place a salinefilled spinal needle into the peritoneal cavity on suction to establish abdominal wall thickness. In this way, trocars of appropriate length can be selected.

Some authorities advocate insufflation to a high intraperitoneal pressure (25 to 30mm Hg) prior to placing the initial umbilical trocar if a closed technique is being used.¹¹ This further elevates the abdominal wall and decreases the risk of preperitoneal trocar placement. After successful trocar placement, immediately reduce intraabdominal pressure to 15 mm Hg to avoid pulmonary compromise, excessive catecholamine release, and subcutaneous emphysema.

 

Techniques to enhance visualization

Excess adipose tissue occupies the pericolic, omental, mesenteric, and retroperitoneal spaces in obese patients, obscuring visualization of intraperitoneal and retroperitoneal structures.

Preoperative mechanical bowel preparation can deflate the bowel and enhance visualization (TABLE 2). At times, an extra ancillary trocar for placement of a bowel retractor also can improve visualization.

In the morbidly obese, insufflation pressure of 15 mm Hg will sometimes produce poor visualization. Obese patients generally tolerate this pressure reasonably well, but increasing it to improve visualization can make adequate oxygenation impossible.

Gasless laparoscopy—in which a mechanical retractor is attached from the table to the patient’s anterior abdominal wall—may help improve pulmonary mechanical parameters. Unfortunately, this technique often produces poorer visualization than insufflation at normal pressure.

A new technique that combines approaches may help avoid the need to convert to laparotomy.¹² In this “Foley lap lift,” a 14-French Foley catheter is passed through the anterior abdominal wall, and the balloon is inflated. The catheter then is elevated and clamped to a retractor holder attached to the angled foot of the bed. This upward traction with continuous gas flow at normal pressure improves visualization without pulmonary compromise.

TABLE 2

Techniques to enhance visualization

Preoperative mechanical bowel preparation Ancillary trocar for placement of bowel retractor Gasless laparoscopy* Foley lap lift*
*See page 70 for details

Close port sites at the fascial level

The risk of bowel herniation through a trocar site is higher in obese patients than the general population because of the greater intraabdominal pressures. Increases in atelectasis from diminished functional residual capacity also predispose the obese patient to postoperative pulmonary complications and can lead to recurrent Valsalva (cough) and subsequent bowel herniation.

Given these risks, it is imperative that all port sites 10 mm or larger be closed at the fascial level. Unfortunately, the distance from the anterior abdominal wall to the fascia underlying these sites makes direct visualization and closure almost impossible.

Fortunately, several fascial closure devices are available and are reasonably inexpensive and easy to use. When using them, be sure to maintain the other port sites, as closure requires direct visualization and a second instrument.

Postoperative strategies

Successful postoperative care builds on preoperative and intraoperative tactics.

Perform aggressive pulmonary toilet

With intraoperative decreases in functional residual capacity, postoperative atelectasis is likely to be profound, with a potential for ventilation/perfusion mismatch and hypoxemia.

Aggressive pulmonary toilet including regular incentive spirometry and deep breathing and coughing exercises is important to reinflate dependent lung regions. Pulse oximetry with sufficient supplementary oxygen also is important to maintain adequate saturation.

Encourage early ambulation

This requires adequate but not oversedating analgesia, early catheter removal, and a motivated nursing staff.

Early ambulation is associated with fewer episodes of deep venous thrombosis, pulmonary complications, and ileus, and also eases pain management.

Continue thrombosis prophylaxis with sequential compression devices, subcutaneous heparin, or both, until the patient is spending most of her time out of bed.

Dr. Robinson reports no relevant financial relationships.

Dr. Isaacson serves on the speakers bureau for Karl Storz Endoscopy.