The micropouch gastric bypass: technical considerations in primary and revisionary operations

Roux-en-Y gastric bypass is an effective procedure for the long-term control of morbid obesity. An eventual revisionary operation, however, is necessary for some patients (0.8-29%). Redo procedures are required for pouch enlargement, staple-line dehiscence, or marginal ulceration. In 1994, the micropouch gastric bypass (MBG) was developed to eliminate the need for a repeat operation. Its design was based on two anatomical principles: 1) The fundus is elastic, aperistaltic, and may significantly dilate over time; 2) The proximal magenstrasse contains a high concentration of parietal cells, which potentiates the risk for marginal ulceration or gastroesophageal reflux after vertical pouch restriction. Construction of a micropouch limited to the gastric cardia avoids using the fundus and proximal lesser curvature, but requires a greater mobilization of the stomach and its peritoneal attachments.

Between February 1994 and February 2000, 1,120 patients underwent the MGB as a primary or revisionary operation. The fundus was mobilized completely, including transection of the left phreno-esophageal and gastrophrenic ligaments. The transected pouch was limited to the gastric cardia with 1 cm of fundus incorporated into the gastrojejunostomy stoma (GJS).

There were 10 anastomotic leaks at the GJS (0.9%). All leaks sealed following surgical drainage or parenteral nutrition. One patient required re-operation (0.09%) for a dilated pouch and marginal ulceration. An additional patient (0.09%) developed a gastrogastric fistula secondary to a pharmacobezoar and stomal stenosis.

With an appreciation for the finer anatomy of the proximal stomach and intra-abdominal esophagus, the micropouch can be constructed safely in both primary and redo procedures. The MGB, now in its seventh year, is durable and has, with rare exception, eliminated pouch enlargement, staple-line separation, reflux esophagitis, and marginal ulceration.