Internal Hernia After Laparoscopic Gastric Bypass: Effect of Closure of the Petersen Defect - Single-Center Study.

Background And Aims: Bowel obstruction due to internal hernia (IH) is a well-known late complication of a laparoscopic roux-en-y gastric bypass (LRYGBP). The objective of this study is to evaluate if closure of the mesenteric defect and Petersen's space will decrease the rate of internal hernias compared to only closure of the mesenteric defect.

Methods: A single-center retrospective descriptive study was performed. All patients with LRYGBP from 2011 till April 2017 were included. An antecolic technique was used with closure of the mesenteric defect with a non-absorbable running suture between 2011 and October 2013 (group A), and from November 2013, we added closure of the Petersen defect (group B).

Results: From a total of 3124 patients, 116 patients (3.71%) had an exploratory laparoscopy due to suspicion of bowel obstruction, but in only 67 (2.14%) patients, an IH was found. Preoperative CT predicted the diagnosis in only 73%. In group A, including 1586 patients, 53 (3.34%) were diagnosed with an internal hernia: 39 at Petersen's space and 14 at the mesenteric defect. The mean time interval was 24.2 months and the mean BMI 25.7 kg/m. After routine closure of the Petersen defect in 1538 patients in group B, an internal hernia during laparoscopy was found in 14 (0.91%) patients after a mean period of 13.5 months: 11 at Petersen's space and 3 at the mesenteric defect. In two subgroups (C and D) with an equal follow-up time (24-42 m), the incidence of 1.15% (8/699) was halved in the closure group of both defects compared to the incidence of 2.58% (23/893) in the group with only closure of the mesenteric defect.

Conclusions: After descriptive analysis, these results can provide strong recommendation of closure of the mesenteric defect and Petersen's space, as we notice a tendency to lower incidence of internal hernias.