The Proximal Gastric Pouch Invariably Contains Acid-Producing Parietal Cells in Roux-en-Y Gastric Bypass

Background: Roux-en-Y gastric bypass (RYGBP) is well tolerated and effective in ameliorating diseases common to morbidly obese patients. A potential drawback, however, is the risk for stomal ulcers, probably due to acid and peptic digestion of the mucosa in the proximal Roux limb. Methods: In 23 RYGBP patients (mean BMI 45 kg/m², age 39 years), the gastro-jejunostomy was performed by circular stapler and the gastric suture ring retrieved for histological examination. 13 consecutive patients received our standard totally transected 4 × 3 cm proximal gastric pouch. The anvil was passed transgastricly and reference biopsies were taken from the gastrotomy in the corpus of the stomach. In the last 10 patients, the pouch size was reduced to 2 × 3 cm by a modified surgical technique. Results: All suture rings from the standard pouches consisted of corpus-fundus mucosa with a large amount of parietal cells, histologically identical to the reference biopsies from the gastrotomy. Also, the 10 suture rings from the modified small pouches contained corpus-fundus mucosa. In 5 of these samples, cardiac mucosa was found, but only in a small segment (6 mm). In addition, 3 patients had esophageal epithelium in the suture ring. Conclusion: The proximal pouch invariably contains acid-producing parietal cells. In order to reduce acid production and, hence, the risk of stomal ulcers, the pouch has to be made as small as possible.