S2880 Transpapillary Cystic Duct: A Rare Novel Genetic Variant

Abstract

Introduction: Patients with cholecystitis often present with abdominal pain, nausea and vomiting. The treatment for cholecystitis often is a cholecystectomy. Pathogenesis of cholecystitis entails blockage of the cystic duct resulting in inflammation up-stream from the site of obstruction. Stones are often the cause of this obstruction, and can often enter the bile duct, causing bile duct obstruction. Cystic duct often merges with the common hepatic duct in the extrahepatic but non-pancreatic portion. Imaging such as Ultrasound and MRI in such cases would reveal a filling defect within the bile duct. We present a case where the cystic duct opened directly at the ampulla. Case Description/Methods: A 68 year-old female presented with abdominal pain, nausea and vomiting. Laboratory testing revealed normal AST, ALT and Alkaline phosphatase. Bilirubin was elevated. Ultrasound imaging revealed findings of cholecystitis. A magnetic resonance cholangiopancreatography was performed (Figure a) that revealed a normal common bile duct (CBD), and a dilated cystic duct with a filling defect consistent with a stone. Interestingly, it revealed cystic duct insertion close to the ampulla. During laparoscopic cholecystectomy, an intraoperative cholangiogram (Figure b) with contrast injection into the cystic duct revealed multiple filling defects in the cystic duct with contrast draining into the small bowel through the papilla. ERCP with cholangioscopy confirmed the cystic duct opening into the ampulla. Treatment entailed ERCP with cholangioscopy and lithotripsy. Discussion: Recognizing anatomical variants and considering these in the differential can help in understanding unusual clinical presentations of biliary pathologies.Figure 1.: a: MRCP images showing stones (green arrow) in cystic duct with cystic duct opening at the ampulla; b: Intraoperative cholangiogram confirming cystic duct stones with cystic duct opening at the ampulla.