P-BN30 Retroperitoneal biloma: a case report of spontaneous retroperitoneal bike leak and collection

Abstract

Abstract Background Retroperitoneal biloma is a rare complication of gallstone disease. Only a handful of cases have been reported in the literature with various mechanisms postulated. Here, we report a case of spontaneous retroperitoneal biloma arising from gallbladder perforation. Methods An 87-year-old female patient presented with right upper quadrant pain in the context of known gallstone disease. Inflammatory markers and liver function tests were deranged. Cross sectional imaging found acute cholecystitis and a gallbadder neck perforation with an impacted 2cm proximal common bile duct (CBD) stone. A cholecystostomy was placed and she improved clinically. However, inflammatory markers remained high, and a subsequent computed tomography (CT) found a large collection in the retroperitoneum. Results The retroperitoneal collection measured 14cm x 7cm, and there had been evidence on prior CT scans of retroperitoneal inflammation. It was urgently drained under ultrasound guidance and found to contain bilious content. Subsequent endoscopic retrograde cholangiopancreatography (ERCP) was unable to retrieve the CBD stone, but left stents either side of the stone. The patient clinically and biochemically improved. She was discharged and had an elective ERCP, which successfully retrieved the stone, with a plan for urgent elective laparoscopic cholecystectomy. Conclusions Here, we report an interesting case of retroperitoneal biloma successfully managed with ultrasound-guided drainage. Perforation of the distal CBD can result in retroperitoneal bile leak, but the proximal CBD stone in this case would have likely prevented passage of bile. A more likely cause is adhesion of the gallbladder neck to the posterior parietal peritoneum due to chronic inflammation, with subsequent perforation and release of bile into the retroperitoneum. This has previously been described in the literature. Regardless of mechanism, knowledge of the potential for this rare complication is important for anticipating and appropriately managing complications of gallbladder perforation.