Duplicated gallbladder with double cystic duct: hidden in plain sight.

Duplicated gallbladder with double cystic duct is a rare anomaly, with 62 cases reported including this case. We present a 76-year-old man who underwent interval laparoscopic cholecystectomy after previous conservative management of acute cholecystitis. Retrograde dissection of gallbladder was performed due to difficult access. Gallbladder was opened at Hartman's pouch which revealed two bile-flowing structures. Cholangiogram was only successful via one of the ducts with no evidence of leak. Subtotal cholecystectomy was performed after consultation with a Hepatobiliary surgeon. Preoperative computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) were reviewed which revealed duplicated gallbladder. CT cholangiogram was performed post-operatively, confirming two separate cystic ducts. Our case emphasizes that anatomical anomalies can still be unappreciated despite having high-resolution CT and MRCP preoperatively, which poses increased risk of biliary tree injury. Routine intraoperative cholangiogram will help avoid bile duct injuries. Literature advises that both gallbladders should be removed to avoid relapse of gallbladder disease.