Internal Hernia After Laparoscopic Gastric Bypass Without Preventive Closure of Mesenteric Defects: a Single Institution's Experience

Background Internal herniation (IH) is a well-known complication after laparoscopic gastric bypass (LGB). Diagnosing and managing IH can be challenging. This retrospective cohort study aimed to achieve a greater understanding of symptomatology, diagnostic tools, complications, risk of IH recurrence, and symptom relief in IH patients. Methods We included patients who underwent LGB surgery at our institution between 2011 and 2015. Mesenteric defects were not preventively closed during LGB. We focused on LGB patients who underwent surgical intervention(s) for suspected IH during a 7-year study period. We studied patient characteristics, (predictive) symptoms and signs, abdominal imaging, operative findings, post-operative course, and risk of (recurrent) IH. Results A total of 1588 patients were included. In total, 243 patients underwent IH-related diagnostic laparoscopy. Radiating pain to the back (OR 2.45,p = .03), post-prandial pain (OR 3.23,p = .00), and leukocytosis (OR 15.53,p = .01) were identified as predictors of IH. The estimated risk of IH-related diagnostic laparoscopy was 16% at 3 years post-LGB, and the risk of confirmed IH was 12%. The estimated risk of diagnostic laparoscopy for suspected recurrent IH was 10% at 5 years post-LGB. In patients who underwent secondary mesenteric defects closure, post-operative symptom relief was reported in 84%. Conclusion This study demonstrates a considerable risk of developing IH after LGB without preventive closure of the mesenteric defects. We emphasize the value of diagnostic laparoscopy to achieve symptom relief in patients with suspicion of IH. Preoperative diagnosis of IH can be improved by being watchful of specific symptoms and signs which can predict the intra-operative presence of IH.