Normal anatomy and complications after gastric bypass surgery: helical CT findings.

OBJECTIVE

To determine the usefulness and potential pitfalls of helical computed tomography (CT) for depiction of normal anatomy and diagnosis of complications after gastric bypass surgery.

METHODS

From March 1998 to July 2002, 100 abdominal and pelvic CT examinations were performed in 72 patients after gastric bypass surgery for treatment of morbid obesity. Two of four attending abdominal radiologists retrospectively assessed the CT images in consensus for normal postoperative gastrointestinal anatomy and complications such as leaks, staple line dehiscence, bowel obstruction, abscess, hepatic or splenic infarction, and hernia. CT findings were compared with clinical, surgical, and other imaging findings.

RESULTS

The gastric pouch, excluded stomach, proximal efferent loop, oversewn jejunal loop, and distal jejunojejunal anastomosis were identified in 96 (96%) of 100 studies and 69 (96%) of 72 patients, 100 (100%) of 100 studies and 72 (100%) of 72 patients, 99 (99%) of 100 studies and 71 (99%) of 72 patients, 88 (88%) of 100 studies and 61 (85%) of 72 patients, and 67 (67%) of 100 studies and 46 (64%) of 72 patients, respectively. The fundus of the excluded stomach was filled with a combination of air, fluid, and contrast material, which mimicked a loculated fluid collection in 15 (15%) of 100 studies and 13 (18%) of 72 patients. Sixty-two abnormalities, detected in 41 patients, included leak (n = 12), loculated fluid collection unrelated to leak (n = 9), markedly distended excluded stomach (n = 6), small-bowel obstruction (n = 6), gastric staple line dehiscence (n = 6), splenic infarction (n = 5), hematoma (n = 5), left hepatic lobe infarction (n = 3), and hernia related to gastric bypass (n = 10, including three internal hernias, three incisional hernias, and four nonincisional ventral hernias). Seventeen patients required a total of 21 CT-guided interventional procedures.

CONCLUSIONS

Helical CT is useful for identifying normal postoperative anatomy and complications after gastric bypass surgery.