Laparoscopic sleeve gastrectomy is safe and effective overall, but staple line reinforcement appears to increase the rate of postsurgical leaks – which were associated with readmissions and, in some cases, reoperations.

A large review of quality improvement data found that staple line reinforcement – an extremely common technique – was associated with a 60% increased risk of leak, compared with closures without staple line reinforcement, Elizabeth R. Berger, MD, and her colleagues reported in the October issue of the Annals of Surgery (2016;264:464-73).

“This study also demonstrates that leaks were significantly more morbid than bleeding with higher readmission and reoperation rates in patients with a leak vs. a bleed,” wrote Dr. Berger of Loyola University, Chicago, and her coauthors. “Therefore, a surgeon should consider the benefits, risks, and costs of each surgical technique in performing a laparoscopic sleeve gastrectomy and selectively utilize those that, in their hands, minimize morbidity while maximizing clinical effectiveness.”

The team examined outcomes in 189,477 laparoscopic sleeve gastrectomies performed by 1,634 surgeons at 720 centers from 2012 to 2014. All of the data were extracted from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program, created in 2012 by the American College of Surgeons and the American Society for Metabolic and Bariatric Surgery.

They examined the impact of staple line reinforcement, oversewing the staple line, bougie size, and distance of the staple line from the pylorus on 30-day outcomes, and their effect on weight loss and weight-related comorbidities at 1 year. Outcomes included morbidity, leak rates, and bleeding, which were examined at both the patient and surgeon levels.

Most patients (126,904; 67%) patients had some type of staple line reinforcement (SLR); the rest had only oversewn staple lines (OSL) or no reinforcement. Leaks occurred in 1,703 patients and bleeds in 1,436 patients. Leaks were more serious than bleeds: Patients with a leak were almost 28% more likely to readmitted and 11% more likely to need a reoperation than were patients who had only a bleed.

At the patient level, those with SLR with or without OSL were 20%-46% more likely to experience a leak than were those who had neither. Bleeding rates were about 70% lower in the SLR groups.

Most surgeons in the analysis (80%) used some type of SLR; almost 20% routinely used only OSL, and 30% routinely used only SLR. At the surgeon level, SLR was associated with a 60% increased risk of a postoperative leak, compared with no reinforcement. There was no association between SLR and bleeding risk, however.

Oversewing had an effect on 1-year weight loss. Patients with oversewn staple lines lost an additional 1.3 points on the body mass index (BMI) scale, compared with patients with no type of reinforcement.

“The reason for increased leaks from SLR is relatively unclear,” the authors wrote. “The two layers of material that are placed within the staple line could increase ischemia or decrease the relative staple heights. At the notches, where one staple firing ends and the next one begins, there is sandwiching of the two layers of staples and a combined four layers of SLR. This bulk may predispose to leaks.”

Larger bougie sizes (BS) seemed more beneficial than did smaller ones, in both the surgeon- and patient-level analyses. A BS of at least 38 French was associated with a 28% decreased risk of a leak (odds ratio 0.72) at the patient level and a 10% decreased risk at the surgeon level (OR 0.90). There were no associations with bleeding.

“Our findings support literature that describes narrower BSs leads to increased ischemia secondary to increased intraluminal pressure, causing more leaks,” the authors wrote.

A BS of at least 40 French had a significant impact on weight loss. At 1 year, patients with the larger BS had lost 2.45 points more on the BMI scale than did those with smaller sizes.

This finding is in accord with other studies, including one that found the best weight-loss outcomes associated with a BS of more than 60 French. “Perhaps the sleeve works because of more rapid emptying, which is favored by a relatively larger BS, rather than because of restriction,” they said.

The distance to the pylorus (DP) from the staple line initiation point was divided into four sections: less than 4 cm; 4-5 cm; 5-6 cm; and 6 cm or more.

On a patient level, there was no association between DP and leak rates. There was, however, an association with bleeding. A DP of 4-4.99 cm had the highest rate, 90%, while a DP of 5-5.99 cm had the lowest (71%). DP was also associated with weight loss on this level, with a distance of more than 6 cm being associated with the biggest BMI decrease (3.7 points).

“Our data show significantly increased excess weight loss in a stepwise fashion as the DP increases,” the authors said. “Our data suggest that as DP increased, there was an increased excess weight loss, possibly explained by preserving the ‘antral mill.’ Stapling further from the pylorus perhaps keeps the antrum’s functional component intact and allows food to enter the distal gut more quickly, leading to earlier satiety and increased weight loss.”

Only 114 surgeons (8%) used a DP of less than 4 cm. There were no significant associations with any 30-day outcomes and DP after adjustment.

The authors had no financial disclosures.

Staple line reinforcement linked to increased leak risk in bariatric surgery