Pathophysiological Factors Involved in Anastomotic Stricture Formation after Roux-en-y Gastric Bypass Surgery (RYGB)

Abstract

Purpose: Recent surveys have shown that the prevalence of obesity in the U.S. has risen to 32%. There are 220,000 bariatric surgical procedures performed yearly in the U.S. and Canada; RYGB is the most common surgical treatment for morbid obesity in the U.S. RYGB reduces both medical complications and mortality in obese patients. A gastrojejunal (GJ) anastomotic stricture occurs in up to 27% of patients after RYGB, but the causes of postoperative strictures are poorly understood. This study was designed to evaluate factors that might increase the risk of GJ stricture formation after RYGB. Methods: This is a retrospective cohort study. Patients (n=165) who underwent open or laparoscopic RYGB from 6/2006 to 3/2011 and who were seen in our bariatric GI clinic at a large, urban community hospital were included. Medical records of all patients were reviewed. We recorded age, gender, ethnicity, body mass index (BMI), surgical technique, and possible factors that could contribute to postoperative stricture formation. The primary endpoint was identification of factors associated with GJ stricture formation. We also performed an analysis of the outcomes of endoscopic management of strictures. Statistical analysis was performed using Chi-squared testing and multivariate analysis. Results: There were 147 women and 18 men: 24.2% Caucasian- and 71.5% Black-Americans. Thirty-five patients (25.6%) developed GJ strictures. BMIs were not different between GJ stricture (mean 50 kg/m2) compared to no stricture (51.5 kg/m2). There was no significant difference in stricture formation in patients using NSAIDs, smoking or who had H. pylori or coronary artery disease. Stricture was more common (p=0.03) in older patients, Caucasians (p=0.005), patients with obstructive sleep apnea (OR 2.46, 95% CI 1.1456 to 5.3232, p=0.02), patients with marginal ulcer formation (OR 3.689, 95% CI 1.5075 to 9.0742, p=0.004), and patients taking proton pump inhibitors (OR 3.20, 95% CI 1.4734 - 6.99, p=0.003). All 35 GJ strictures in our study were successfully treated with endoscopic pneumatic dilation with a through-the-scope balloon dilator. An average of two sessions was required for symptomatic improvement, but 1 patient required 9 dilation sessions and then injection of Triamcinolone. Conclusion: Our findings show that age, ethnicity, obstructive sleep apnea, marginal ulcer formation and use of proton pump inhibitors are associated with statistically significant increased risk of GJ anastomotic stricture formation after RYGB surgery. Sleep apnea may increase the risk of ischemia. These findings will be used in the development of a prospective protocol. GJ strictures were successfully treated with balloon dilation, which required an average of two sessions.