Pouch Volume and Pouch Migration after Roux-en-Y Gastric Bypass: A Comparison of Gastroscopy and 3D-CT Volumetry – Is there a “Migration Crisis”?

Abstract Background Roux-en-Y gastric bypass (RYGB) is the second most frequently performed bariatric procedure worldwide. While pouch migration is a common phenomenon after sleeve gastrectomy (SG), it has hardly been documented after RYGB so far. Objectives The aim of this study was to correlate the diagnostic performance of gastroscopy of the gastroesophageal junction with 3-dimensional (3D) computed tomography (CT) during postoperative care of patients revised due to weight regain after RYGB, with particular attention to intrathoracic pouch migration (ITM) and pouch volume. Setting University Hospital Setting, Austria Material and Methods Thirty RYGB patients that were revised due to weight regain (median age 37.5 years) before 12/2017 were included in this prospective study. CT findings were correlated with gastroscopy regarding pouch size and ITM. Pouch distension was achieved with both oral contrast and effervescent granules. All patients had CT and gastroscopy on the same day. In addition, patients were evaluated for reflux disease based on clinical history. Results ITM was found in 20/30 (66.7%) patients in CT whereas gastroscopy did not correctly identify any herniation. In 16/28 (57.1%) subjects pouch measurements at gastroscopy and CT showed a difference smaller than 40%. In two patients, pouch distension was not sufficient for CT volumetry. The intraclass correlation coefficient (ICC) proved to be 0.594. Symptomatic reflux was present in 10/30 (33.3%) patients, five of whom had ITM. Conclusion ITM is an underreported finding after revised RYGB and missed in gastroscopy. In terms of pouch volume, 3D-CT volumetry demonstrated only moderate agreement with gastroscopy.