S3555 Perforated Emphysematous Cholecystitis as a Complication of a Pancreaticoduodenal Artery Pseudoaneurysm

Introduction: A pseudoaneurysm is a false aneurysm that develops from an arterial breach resulting in a hematoma contained within the outermost layer of the arterial wall or surrounding perivascular soft tissue. Common etiologies of pseudoaneurysms include pancreatitis, trauma, vasculitis, and iatrogenic injury. While complications typically arise from rupture and hemorrhage, in rare instances, mass effect from a pseudoaneurysm can result in complications such as gastric outlet, duodenal, or biliary obstruction. Case Description/Methods: A 72-year-old man with a history of a pulmonary embolism on rivaroxaban presented to the hospital for abdominal pain. His vitals were stable, and his exam was notable for jaundice and epigastric tenderness. Labs demonstrated significantly elevated total bilirubin with associated transaminitis. Computed tomography revealed a pancreaticoduodenal artery (PDA) pseudoaneurysm with mass effect on the biliary tree, severe common bile duct dilatation, and marked gallbladder distension. He successfully underwent interventional radiology-guided coil embolization of the pseudoaneurysm and endoscopic retrograde cholangiopancreatography (ERCP) with placement of a plastic stent in the common bile duct. The patient then had rapid improvement of his total bilirubin and abdominal pain. Four days following his ERCP, the patient developed septic shock with rebound tenderness. A repeat computed tomography showed appropriate positioning of the embolization coils and the biliary stent; however, perforated emphysematous cholecystitis was now observed. The patient subsequently underwent emergent open cholecystectomy, and following the surgery, he gradually improved with antibiotics before eventually being discharged from the hospital. Discussion: A PDA pseudoaneurysm is a rare but serious etiology of biliary obstruction that has been known to lead to significant complications such as pancreatitis or cholangitis. In such cases, management typically involves endovascular or surgical intervention of the pseudoaneurysm and ERCP with stenting for biliary decompression. To the best of our knowledge, emphysematous or perforated cholecystitis has not been reported in the context of biliary obstruction secondary to a visceral pseudoaneurysm. This case highlights that even if adequate biliary decompression and endovascular intervention is achieved, patients may still be at risk for additional severe complications. Optimal management is unclear, but early cholecystectomy may be beneficial for patients who are at high risk for complicated cholecystitis to prevent adverse outcomes and improve survival.