Internal Herniation Incidence After RYGB and the Predictive Ability of a CT Scan as a Diagnostic Tool

Purpose The clinical diagnosis of an internal herniation (IH) after a Roux-en-Y Gastric Bypass (RYGB) remains difficult; therefore, performing a CT scan is usually part of the diagnostic process. The goal of this study was to assess the incidence of IH in patients with open and closed MD (mesenteric defect) and to study if the ability to diagnose an IH with a CT scan is different between these groups. Materials and Methods IH was defined as a visible intestine through the mesenteric defect underneath the jejunojejunostomy and/or in the Petersen's space. CT scan outcomes were compared with the clinical diagnosis of an IH. Until 31 June 2013, standard care was to leave mesenteric defects (MDs) open; after this date, they were always closed. Results The incidence of IH in the primarily non-closed group was 3.9%, and in the primarily closed group, this was 1.3% (p = 0.001). In group A (non-closed MD and CT), the sensitivity of the CT scan was 80%, and specificity was 0%. In group C (closed MD and CT), the sensitivity was 64.7%, and specificity was 89.5%. In group B (non-closed, no CT), an IH was visible in 58.7% of the cases and not in 41.3%. In group D (only a re-laparoscopy), an IH was visible in 34.3% of the cases and not in 65.7%. Conclusions Using the CT scan in suspected IH is not useful in if the MDs were not closed. If the MDs were closed, then a CT scan is predictive for the diagnosis IH.

Automated summary

The incidence of IH was higher in the non-closed MD group compared to the closed MD group. The sensitivity and specificity of CT scan in diagnosing IH varied between the non-closed and closed MD groups. Using CT scan for suspected IH is not useful if the mesenteric defects were not closed, while it is predictive for diagnosing IH if the defects were closed.