Causes of small bowel obstruction after laparoscopic gastric bypass

Small bowel obstruction after laparoscopic Roux-en-Y gastric bypass is not a rare complication, occurring in approximately 3% of patients. The goal of this study was to review the causes and timing of small bowel obstruction as an aid to diagnosis, treatment, and prevention.

The records of consecutive patients who underwent laparoscopic Roux-en-Y gastric bypass at the authors' center from 4/99 to 7/03 were retrospectively reviewed. All the patients had a laparoscopic handsewn gastrojejunostomy and a stapled jejunojejunostomy. The Roux limb was placed retrocolically in the first 405 patients and antecolically in the next 1,310 patients.

Altogether, 1,715 patients underwent a total laparoscopic Roux-en-Y gastric bypass at the authors' bariatric center. In 51 patients, 55 small bowel obstructions occurred (3%) during a median follow-up period of 21 months (range, 1–52 months). Small bowel obstruction developed in 27 (7%) of the retrocolic patients, as compared with 24 (2%) of the antecolic patients (p < 0.001, chi-square). The causes of small bowel obstruction were adhesive bands (n = 14), obstruction at the jejunojejunostomy from kinking or narrowing (n = 13), internal hernia or external compression at the transverse mesocolon (n = 11), internal hernia through the jejunal mesentery (n = 8) incarcerated abdominal wall hernia (n = 4), and other (n = 5). For patients in whom small bowel obstruction developed in the first 3 weeks after their bypass surgery bowel resection was required in 19 of 24 patients, as compared with 6 of 31 patients in whom obstruction develop after 3 weeks (p < 0.001, chi-square).

Early small bowel obstructions tend to result from technical problems with the Roux limb and require revision of the bypass or small bowel resection significantly more often than late obstructions. The latter group of obstructions usually result from adhesions or hernias, which could be handled laparoscopically without bowel resection. The position of the Roux limb (retrocolic vs antecolic) appeared to influence the incidence of small bowel obstruction. In the current series, changing the position of the jejunal bypass limb from retrocolic to antecolic significantly decreased the overall incidence of small bowel obstruction because it eliminated one of the most common sites for obstruction: the mesocolon.