S3506 When the Brain Meets the Bile: A Rare Case of Ventriculo-Gallbladder Shunt Fistulization

Introduction: A cholecystocutaneous fistula—an uncommon pathological communication between the gallbladder and skin—most frequently results from untreated calculous cholecystitis. We present a unique case of cholecystocutaneous fistula complicating a ventriculo-gallbladder (VGB) shunt. Case Description/Methods: A 60-year-old man with a history of congenital hydrocephalus status post ventriculoperitoneal (VP) shunt—later revised to a VGB shunt—presented to the emergency department with nausea, vomiting, abdominal pain, fever, and right upper quadrant (right upper quadrant) bilious discharge, raising concern for a cholecystocutaneous fistula and shunt obstruction. A multidisciplinary team, including Neurosurgery, General Surgery, Neurology, Infectious Disease, and Interventional GI, was consulted. Due to a frozen abdomen, the patient was deemed ineligible for abdominal surgery. Cerebrospinal fluid (CSF) cultures identified Staphylococcus mitis, prompting antibiotic therapy with vancomycin, ceftriaxone, and metronidazole. On 5/12/2025, shunt externalization with ventricular drains was performed. Despite persistent bilious output from a right upper quadrant ostomy, magnetic resonance cholangiopancreatography (MRCP) showed no biliary leak. Contrast-enhanced computed tomography demonstrated retracted ventriculo-cystic shunt tubing herniating through the gallbladder fundus. The retained ventriculo-cystic shunt tubing was surgically removed, and the patient underwent a right parietal endoscopic third ventriculostomy on 5/20/2025. Biliary stenting was considered beneficial after shunt removal, and the patient underwent endoscopic retrograde cholangiopancreatography (ERCP) on 5/22/2025 with sphincterotomy and placement of 1 biliary stent in the common bile duct. The patient was subsequently transferred from the neurosurgical intensive care unit to the medical-surgical floor, with resolution of bilious ostomy output. Outpatient follow-up was arranged for ongoing management. Discussion: While ventriculo-enteric fistulas have been documented as a complication of VGB shunts, cholecystocutaneous fistulas remain unreported in the literature. Although rare today, patients presenting with right upper quadrant bilious discharge warrant thorough evaluation. Initial management involves drainage and antibiotic therapy, with definitive treatment consisting of open cholecystectomy and excision of the fistulous tract. However, in patients who are too debilitated for surgery, we propose that removing the distal VGB shunt apparatus alongside biliary stenting may reduce biliary flow through the fistula, promoting spontaneous closure.