Gallbladder Agenesis With Refractory Choledocholithiasis: 232

Introduction: Congenital agenesis of the gallbladder is a rare anomaly which is usually asymptomatic and found incidentally. Case Report: A 63 year-old female presented with jaundice and right upper quadrant abdominal pain with nausea and vomiting. Her liver enzymes were elevated in a mixed cholestatic and hepatocellular pattern. An abdominal ultrasound failed to adequately visualize the gallbladder attributed to the patient's obesity, but a structure adjacent to the duodenum with a small calcification was presumed to be a contracted gallbladder with small stones. There was lack of extrahepatic bile duct dilation. Based on these findings an endoscopic ultrasound (EUS) was done demonstrating a dilated common bile duct to 13 mm along with extensive choledocholithiasis. An ERCP revealed numerous large stones within the common bile duct up to 15 mm in size. Sphincterotomy with balloon sweep was performed, however two large stones 15 mm in size could not be extracted. One week later, ERCP with mechanical lithotripsy (ML) was done with partial stone extraction. A repeat ERCP was performed utilizing electrohydraulic lithotripsy (EHL), resulting in reduction of the common bile duct stones by 30-50%. Another ERCP six weeks later utilizing ML was repeated, but the stones remained impacted in the common bile duct. Due to the patient's refractory choledocholithiasis despite ML and EHL, the decision was made to perform external shock wave lithotripsy (ESWL). ESWL was successfully performed with complete fragmentation of the remaining stones. A final ERCP was done successfully extracting all the stone fragments. The patient was referred for laparascopic cholecystectomy, however during surgery it became apparent that the patient had congenital agenesis of the gallbladder. Conclusion: In agenesis of the gallbladder, 25-50% of patients will develop stones in the common bile duct. The increased frequency of choledocholithiasis in patients with gallbladder agenesis has been hypothesized to be a result of hypertonic muscular retrograde contraction of the sphincter of Oddi. This results in biliary dyskinesia leading to common duct dilatation, biliary stasis, and gallstone formation2. Although agenesis of the gallbladder is a rare finding, patients with agenesis of the gallbladder are at increased risk of developing de novo choledocholithiasis which may be challenging to extract and require unconventional methods.Figure 1