Imaging of the biliary sump syndrome

Side-to-side choledochoduodenostomy is a safe and effective surgical technique to improve biliary drainage in selected patients. The segment of common bile duct between the anastomosis and the ampulla of Vater may act as a stagnant reservoir or sump. When debris, stones, or infected bile accumulates in the sump, usually because of malfunction of the ampulla of Vater, recurrent abdominal pain or symptoms of cholangitis, pancreatitis, or biliary obstruction may develop. This uncommon (0.14-1.30%) complication is known as the sump syndrome. On imaging studies, diagnostic findings are debris or stone(s) in the common bile duct. Suggestive findings are dilated bile or pancreatic ducts, and changes due to pancreatitis, cholangitis, or liver abscess. Patients with this syndrome frequently have multiple imaging studies before the condition is recognized. The purpose of this essay is to illustrate the imaging findings of this syndrome.