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

BACKGROUND: 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. METHODS: 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). RESULTS: 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. CONCLUSION: 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.

Micropouch gastric bypass: indications for gastrostomy tube placement in the bypassed stomach.

BACKGROUND: Since 1994 we have performed the "micropouch" gastric bypass (MGB) procedure for morbid obesity. In our MGB operation, the transected gastric reservoir is limited to the cardia of the stomach. The Roux and biliopancreatic limbs measure 200 and 150 cm, respectively; radiographic or endoscopic access to the bypassed stomach is therefore excluded. METHODS: A retrospective analysis of 1,120 MGB operations revealed that 33 patients (2.9%) developed a potentially life-threatening postoperative complication requiring emergency re-operation or prolonged hospitalization. Complications included anastomotic leaks, fascial dehiscence, gastro-enteric obstructions, peptic ulcers, and pancreatitis. Each complication was analyzed to determine if gastrostomy tube (G-tube) placement at the time of gastric bypass could have affected complication outcome or obviated the need for repeat laparotomy. RESULTS: In 19 patients (1.6% of total cohort), G-tube placement would have significantly affected complication outcome. In four instances, it would have prevented emergency re-operation. CONCLUSIONS: Routine gastrostomy tube placement at the time of gastric bypass is not necessary in all patients. For patients who are at high risk for a gastro-enteric obstruction or an anastomotic leak, G-tube placement is recommended and is often therapeutic.

Marginal ulcer after gastric bypass: a prospective 3-year study of 173 patients.

BACKGROUND: Marginal ulceration (MU) after Roux-en-Y gastric bypass (RYGB) is a well-recognized complication. Its incidence varies between 1% and 16%. Factors associated with the development of MU include pouch size, pouch orientation, staple line integrity, and mucosal ischemia. Nonsteroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori may also contribute to MU, but their mechanism of action in the RYGB patient has not been studied. METHODS: In 1994 a prospective 3-year study was designed to document the incidence of MU after near-total gastric bypass (NTGB). In this procedure the transected pouch was limited to the cardia, and the gastrojejunostomy was made along the greater curvature. A total of 173 patients entered the study. All patients who experienced postoperative nausea, vomiting, or abdominal pain underwent endoscopic examination of the pouch, stoma, and proximal Roux-en-Y limb. Gastrograffin studies were used within the first 2 weeks of operation. RESULTS: One year after operation, MU was not identified in any patient. At 3 years follow-up, MU was documented in one patient (0.6%) with a dilated gastric reservoir (60 cc). CONCLUSION: This study reviews the etiology, diagnosis, and treatment of MU in the RYGB patient and offers specific recommendations to reduce its occurrence. It also confirms a preliminary impression that NTGB is an effective operation in preventing MU formation.

Establishment of a human pancreatic tumor xenograft model: potential application for preclinical evaluation of novel therapeutic agents.

Adenocarcinoma of the pancreas is currently the fifth leading cause of death in the United States. It remains generally incurable by available treatment modalities. We report here on the characterization of a permanent pancreatic cell line (KCI-MOH1), established as a xenograft in severe combined immune deficient (SCID) mice, from a 74 year-old African American male patient diagnosed with pancreatic cancer. Sections from paraffin-embedded tumors excised from SCID mice revealed typical adenocarcinoma of the pancreas. Karyotypic analysis of cultured cells derived from tumors grown in SCID mice revealed a male karyotype with multiple clonal aberrations: 42, XY, add (3)(p11.2), der(7) t(7;12) (p22;q12), -10, -12, add (14)(p11), -18, add (20)(q13)-22/84, idemx2. Immunostaining of KCI-MOH1 tissues shows strong expression of p53 and p21 proteins. The xenograft model was established by transplanting the KCI-MOH1 cells subcutaneously (s.c.) in SCID mice. When the s.c. tumor was transplanted in vivo to other SCID mice, the success rate was 100%, with a doubling time of 8.5 days. The SCID mouse xenograft model was used to test the efficacy of selected standard chemotherapeutic drugs (taxol, gemcitabine, 5-fluorouracil, and Ara-C) and novel biological agents (Bryostatin 1 and Auristatin-PE). Results show that gemcitabine, Ara-C, and Bryostatin 1 were active against KCI-MOH1. The xenograft described herein can be used as an animal model to facilitate the development of novel therapeutic agents against human pancreatic cancers.