Does Pouch Size Matter?

Background: Mechanical restriction, malabsorption, and hormonal changes appear to play a role in weight loss after Roux-en-Y gastric bypass (RYGBP). This investigation chose to investigate one aspect of the restrictive role of gastric bypass: the pouch size. Our hypothesis was that a small pouch size with no fundus after laparoscopic RYGBP (LRYGBP) would lead to greater loss of excess weight and weight loss success.

Methods: Upper gastrointestinal radiological (UGI) studies were retrospectively reviewed by three blinded experts (2 bariatric surgeons and 1 expert radiologist), to determine pouch size and fundus size. The following grading system was utilized: Size I - smaller than average pouch, Size II - average pouch, Size III larger than average pouch, and Size IV - over 3 times the size of an average pouch. Fundus 0 - no fundus appreciated, Fundus I - slight amount of fundus barely noted, Fundus II - fundus noted, Fundus III - large amount of fundus noted, and Fundus IV - majority of the pouch was fundus. Percentage of excess weight loss (%EWL) and successful weight loss (A. >50% EWL, B. within 50% of ideal body weight, C. loss of >25% of preoperative weight) were calculated.

Results: There were 59 patients in this study with 97% follow-up of >1 year. No Size IV or Fundus IV were noted. There were no statistically significant differences between in %EWL or success for either pouch size or fundus size.

Conclusions: While there may be a trend for the mean %EWL to be lower with larger pouches and larger amounts of fundus, no significant differences were found. Larger pouches and the presence of fundus (within reason) still result in a high rate of success after LRYGBP.