P-BN16 Gallbladder agenesis in a gentleman presenting with biliary sepsis: a case report and review of literature

Abstract

Abstract Background Gallbladder agenesis (GBA) is a well-recognised, yet rare embryological malformation, that is thought to stem from a failure of the gallbladder and cystic duct to bud from the common bile duct in the 5th week of gestation. The anomaly has an estimated incidence of 10-65 per 100 000 and is often an incidental finding. A quarter of those affected are symptomatic, often presenting in a similar manner to cholecystitis or choledocholithiasis. There is a lack of awareness and guidance on its investigation and management, making GBA a diagnostic challenge, which often leads to unnecessary high-risk surgical exploration. Methods A 64-year-old man presented with right upper quadrant abdominal pain, fevers, jaundice and persistent vomiting. On examination he was confused, visibly jaundiced and septic with deranged liver function tests. An initial ultrasound scan of the abdomen revealed dilated common bile ducts, with no evidence of choledocholithiasis, however, a gallbladder could not be identified. Magnetic resonance cholangiopancreatography confirmed a ‘post-cholecystectomy’ picture, despite no history of abdominal surgery. This led us to the diagnosis of gallbladder agenesis. Results There are no dedicated guidelines regarding the investigation and management of GBA. Efforts have been made to stratify the diagnostic imaging of GBA. Malde et al suggest that if the gallbladder is not visualised on USS, the next most appropriate investigations in order of accuracy are MRCP, CT and ERCP, respectively. Interestingly, they further suggest that if results of imaging remain inconclusive, they should be repeated again once the acute phase of the illness or symptoms have resolved. Inadvertently, this suggestion was applied in our case, as the patient underwent a repeat MRCP following the resolution of his acute symptoms. In our case, MRCP allowed an effective final diagnosis, avoiding unnecessary investigations and exploratory surgery. It also provided a detailed anatomical picture, excluding the possibility of an ectopic gallbladder. Conclusions The present case accentuates the importance of non-invasive imaging such as MRCP in appropriately diagnosing this phenomenon and avoiding unnecessary operative exploration.