Validation of pouch size measurement following the Swedish adjustable gastric banding using endoscopy, MRI and barium swallow

Background: Pouch volume appears to be of major importance for subsequent weight loss following any gastric restriction type of surgery for morbid obesity. In order to be able to evaluate pouch volume following Swedish Adjustable Gastric Banding (SAGE), an endoscopic pouch volume classification system was designed in which pouch volume is classified in five categories. The aim of this study was to validate the endoscopic classification system using MRI and barium swallow as reference methods for pouch volume measurement. Methods: Twenty patients (13 women and seven men) were operated for obesity with SAGE. They were investigated a mean of 3 years (6 weeks-5.5 years) after surgery and had at that time lost a mean of 60 (12-112)kg. During the same afternoon they sequentially underwent endoscopy, MRI and barium swallow with an empty stomach. Results: The mean pouch volume measured with MRI was 70 mi (0-180 mi) and with barium swallow was 72 mi (0-195 mi). In 17/20 patients the volume as measured by MRI and barium swallow was in the same volume category as with endoscopy. The correlation measured according to Pearson was significant between endoscopy on one hand and MRI/barium swallow both independently and together (p < 0.001). Conclusion: Based on these results we are confident in using our endoscopic classification system for postoperative follow-up of pouch volume.