Imaging of Small Bowel Obstruction following Gastric Bypass Surgery for Morbid Obesity: A retrospective review.

Objectives: This study is a single institution retrospective evaluation of imaging findings of small bowel obstruction (SBO) after retrocolic antegastric Roux-en-Y gastric bypass surgery for morbid obesity.

Methods: The radiological database of 490 patients who underwent gastric bypass surgery for morbid obesity from January 2001-2005 at the Royal Victoria Hospital McGill University Health Center was searched for SBO complications related to the procedure. There were 22 cases of small bowel obstruction related to the procedure. Ten patients had abdominal and pelvic computed tomography (CT) scans, 12 patients had upper gastrointestinal (UGI) and small bowel follow through (SBFT).

Results: Among 22 cases of SBO, 14 cases were due to anastomotic stenosis or adhesion, 7 due to internal hernia and one to jejuno-jejunal intussusception. Among the 14 patients with SBO related to adhesion and anastomotic narrowing, 11 patients were managed medically and 3 cases managed surgically. CT scans correctly diagnosed 4 out of 5 cases including the 3 patients managed surgically and UGI and SBFT examinations diagnosed the remaining 9 cases that were managed medically. Among the 7 patients with internal hernias, CT scans correctly diagnosed 2 out of 4 cases, while UGI and SBFT examinations correctly diagnosed 1 out of 3. The jejuno-jejunal intussusception was correctly diagnosed by CT scan.

Conclusion: The most frequent cause of SBO is anastomotic narrowing or adhesion. CT scan remains the most appropriate imaging modality in diagnosing acute presentation of SBO caused by internal hernia or adhesion/anastomotic narrowing. UGI and SBFT appear more appropriate for diagnosing the subacute insidious presentation of adhesive partial SBO.