S20 Common Bile Duct Dilation After Roux-en-Y Gastric Bypass Surgery

Abstract

Introduction: As the obesity epidemic continues, surgical interventions to address this issue have become more prevalent. One of the most widely used methods for bariatric surgery is Roux-en-Y gastric bypass (RYGB). A unique problem that has been identified in the post-bariatric surgery population is biliary duct dilation without specific pancreatobiliary pathology. This study aims to evaluate the change in common bile duct (CBD) diameter following RGYB. Methods: This was a single center retrospective study that evaluated patients who had undergone RYGB between 1/1/2010 and 12/31/2020. Adults (>18 years of age) who had CT imaging for non-pancreatobiliary reasons before and after their RYGB were included. Patients with known pancreatobiliary pathology were excluded from analysis. An abdominal radiologist measured the diameters of the CBD in all images at the porta hepatis. Linear regression modeling and t-tests in SPSS were used to analyze data. Results: 46 patients met the inclusion criteria. The average age and BMI at time of RYGB was 48.4 years and 46.4. The average age and BMI at time of post-operative CBD measurement was 49 years and 38.1. The mean CBD diameter of all included patients pre-RYGB was 5.93 mm (SD 1.5) and the mean diameter post-RYGB was 7.0 mm (SD 3.3). Mean diameter change between pre and post RYGB was 1.31 mm (SD 2.8, P < 0.05). Controlling for prior cholecystectomy as well as narcotic use at the time of post-operative imaging, the change in CBD diameter was 1.15 mm (SD 0.6, P value 0.06). Prior cholecystectomy and narcotic usage did not affect in person change of CBD diameter (P 0.9, P 0.6). Conclusion: There are many known causes of non-pathological biliary duct dilation, including age, history of cholecystectomy and narcotic use. Our data shows that biliary dilation can occur after bariatric surgery. This finding is important because endoscopic biliary evaluation with EUS and ERCP in RYGB anatomy is challenging and associated with high failure rates. Other biliary interventions like laparoscopic assisted, percutaneous and trans-gastric procedures are associated with higher risk of complications. Given these issues, it is crucial for patients to have a strong indication for biliary intervention. As physicians treat an increasing number of patients with RYGB anatomy, they must consider that incidentally found biliary dilation might not necessarily indicate the presence of biliary pathology in order to prevent avoidable imaging and interventions.