Surgery duration linked to VTE risk

Team performing surgery

Credit: Piotr Bodzek

New research suggests that, as the duration of surgery increases, so does the risk of venous thromboembolism (VTE).

Compared with a surgical procedure of average duration, patients who underwent the longest procedures had a 1.27-fold increase in the risk of developing a VTE.

In 3 of the most common procedures—gall bladder removal, appendectomy, and gastric bypass—surgery duration was a significant, independent risk factor for VTE.

Though these results suggest an association between surgical time and VTE, the researchers said they could not confirm a causal relationship.

John Y.S. Kim, MD, of Northwestern University’s Feinberg School of Medicine in Chicago, and his colleagues reported these findings in JAMA Surgery.

The researchers analyzed data from the American College of Surgeons National Surgical Quality Improvement Program to examine the association between surgical duration and the incidence of VTE.

The study included more than 1.4 million patients who had surgery under general anesthesia at 315 US hospitals from 2005 to 2011.

A total of 13,809 patients (0.96%) had a postoperative VTE, with 10,198 (0.71%) developing deep vein thrombosis and 4772 (0.33%) developing a pulmonary embolism.

The rates of each of these events consistently increased with the duration of the surgical procedure.

The researchers divided patients into 5 quintiles representing surgery duration. In the first quintile (representing the relatively shortest procedures), there were 2033 VTEs. This was followed by 2278 in the second quintile, 2478 in the third, 2960 in the fourth, and 4060 in the fifth.

Compared with the third quintile (which served as a reference), the odds ratio (OR) for developing VTE in the first quintile was 0.86 (P<0.01). In the second quintile, the OR was 0.98 (P=0.39). The fourth and fifth quintiles had ORs of 1.10 and 1.27, respectively (P<0.001 for both).

The association between VTE incidence and the longest procedures was significant in 82% of 1000 bootstrap samples. In this analysis, there was a significant association (P<0.001) between surgery duration and VTE for gynecologic, neurologic, otolaryngologic, urologic, and vascular procedures.

In each of the 3 most common procedures, surgery duration was a significant, independent risk factor for VTE. A 1-hour increase in surgical time carried an OR of 1.18 for gall bladder removal, 1.18

for appendectomy, and 1.26 for gastric bypass (P<0.05 for all).

The researchers said these results appear to validate the widely held, but not previously substantiated, belief that longer operations are associated with a higher risk of VTE. This information could help improve VTE risk modeling, enhance thromboprophylaxis guidelines, and better inform surgical decision making.

Team performing surgery

Credit: Piotr Bodzek

New research suggests that, as the duration of surgery increases, so does the risk of venous thromboembolism (VTE).

Compared with a surgical procedure of average duration, patients who underwent the longest procedures had a 1.27-fold increase in the risk of developing a VTE.

In 3 of the most common procedures—gall bladder removal, appendectomy, and gastric bypass—surgery duration was a significant, independent risk factor for VTE.

Though these results suggest an association between surgical time and VTE, the researchers said they could not confirm a causal relationship.

John Y.S. Kim, MD, of Northwestern University’s Feinberg School of Medicine in Chicago, and his colleagues reported these findings in JAMA Surgery.

The researchers analyzed data from the American College of Surgeons National Surgical Quality Improvement Program to examine the association between surgical duration and the incidence of VTE.

The study included more than 1.4 million patients who had surgery under general anesthesia at 315 US hospitals from 2005 to 2011.

A total of 13,809 patients (0.96%) had a postoperative VTE, with 10,198 (0.71%) developing deep vein thrombosis and 4772 (0.33%) developing a pulmonary embolism.

The rates of each of these events consistently increased with the duration of the surgical procedure.

The researchers divided patients into 5 quintiles representing surgery duration. In the first quintile (representing the relatively shortest procedures), there were 2033 VTEs. This was followed by 2278 in the second quintile, 2478 in the third, 2960 in the fourth, and 4060 in the fifth.

Compared with the third quintile (which served as a reference), the odds ratio (OR) for developing VTE in the first quintile was 0.86 (P<0.01). In the second quintile, the OR was 0.98 (P=0.39). The fourth and fifth quintiles had ORs of 1.10 and 1.27, respectively (P<0.001 for both).

The association between VTE incidence and the longest procedures was significant in 82% of 1000 bootstrap samples. In this analysis, there was a significant association (P<0.001) between surgery duration and VTE for gynecologic, neurologic, otolaryngologic, urologic, and vascular procedures.

In each of the 3 most common procedures, surgery duration was a significant, independent risk factor for VTE. A 1-hour increase in surgical time carried an OR of 1.18 for gall bladder removal, 1.18

for appendectomy, and 1.26 for gastric bypass (P<0.05 for all).

The researchers said these results appear to validate the widely held, but not previously substantiated, belief that longer operations are associated with a higher risk of VTE. This information could help improve VTE risk modeling, enhance thromboprophylaxis guidelines, and better inform surgical decision making.

Team performing surgery

Credit: Piotr Bodzek

New research suggests that, as the duration of surgery increases, so does the risk of venous thromboembolism (VTE).

Compared with a surgical procedure of average duration, patients who underwent the longest procedures had a 1.27-fold increase in the risk of developing a VTE.

In 3 of the most common procedures—gall bladder removal, appendectomy, and gastric bypass—surgery duration was a significant, independent risk factor for VTE.

Though these results suggest an association between surgical time and VTE, the researchers said they could not confirm a causal relationship.

John Y.S. Kim, MD, of Northwestern University’s Feinberg School of Medicine in Chicago, and his colleagues reported these findings in JAMA Surgery.

The researchers analyzed data from the American College of Surgeons National Surgical Quality Improvement Program to examine the association between surgical duration and the incidence of VTE.

The study included more than 1.4 million patients who had surgery under general anesthesia at 315 US hospitals from 2005 to 2011.

A total of 13,809 patients (0.96%) had a postoperative VTE, with 10,198 (0.71%) developing deep vein thrombosis and 4772 (0.33%) developing a pulmonary embolism.

The rates of each of these events consistently increased with the duration of the surgical procedure.

The researchers divided patients into 5 quintiles representing surgery duration. In the first quintile (representing the relatively shortest procedures), there were 2033 VTEs. This was followed by 2278 in the second quintile, 2478 in the third, 2960 in the fourth, and 4060 in the fifth.

Compared with the third quintile (which served as a reference), the odds ratio (OR) for developing VTE in the first quintile was 0.86 (P<0.01). In the second quintile, the OR was 0.98 (P=0.39). The fourth and fifth quintiles had ORs of 1.10 and 1.27, respectively (P<0.001 for both).

The association between VTE incidence and the longest procedures was significant in 82% of 1000 bootstrap samples. In this analysis, there was a significant association (P<0.001) between surgery duration and VTE for gynecologic, neurologic, otolaryngologic, urologic, and vascular procedures.

In each of the 3 most common procedures, surgery duration was a significant, independent risk factor for VTE. A 1-hour increase in surgical time carried an OR of 1.18 for gall bladder removal, 1.18

for appendectomy, and 1.26 for gastric bypass (P<0.05 for all).

The researchers said these results appear to validate the widely held, but not previously substantiated, belief that longer operations are associated with a higher risk of VTE. This information could help improve VTE risk modeling, enhance thromboprophylaxis guidelines, and better inform surgical decision making.