Radiological Findings in Symptomatic Internal Hernias After Laparoscopic Gastric Bypass

Background: Internal hernias (IHs) can complicate laparoscopic Roux-en-Y gastric bypass (LRYGB). A number of radiological investigations can be used in the diagnosis. These include plain X-rays, upper gastrointestinal (UGI) series, ultrasound, and computed tomography (CT) scanning. We present radiological findings in our series of 58 symptomatic internal hernias based on our 6-year experience (2000-2006) of 2,572 LRYGB patients.

Methods: A retrospective chart review was performed of all patients undergoing LRYGB who developed symptomatic internal hernia requiring operative intervention between January 1, 2000 and September 15, 2006. Types of radiological tests performed and their results were recorded.

Results: Fifty-eight symptomatic internal hernias were recorded, of which 56/58 (97%) underwent radiological investigation; 2/58 went directly to surgery. Of the 56 patients who underwent diagnostic imaging, 41 plain abdominal X-rays, 37 CT scans, 26 UGI series, and eight ultrasound scans were performed. Sixty-five percent of UGI series and 92% of CT scans had positive features diagnostic of internal hernia. Performing both CT and UGI series successfully diagnosed IH in 100% of cases. Subgroup analysis did not reveal any association between positive result of imaging test and type of internal hernia.

Conclusion: CT scanning is the single most effective radiological investigation for diagnosing internal hernias post-LRYGB. In non-diagnostic cases, the addition of an upper GI series increases the diagnostic rate to 100%.