Spontaneous choledochoduodenal fistula after metallic biliary stent placement in a patient with ampulla of vater carcinoma

Biliary stent-related enteric perforations are very rare complications that are caused by the sharp end of a metallic stent, stent migration, or tumor invasion. Moreover, the choledochoduodenal fistula resulting from metallic biliary stent-induced perforation is extremely rare. Here, we report a case in which a spontaneous choledochoduodenal fistula occurred after biliary metallic stent placement in a patient with an Ampulla of Vater carcinoma but was successfully managed by supportive treatments, including nasobiliary drainage. This case might have occurred as the result of a rupture of the bile duct following pressure necrosis and inflammation caused by impacted calculi and food materials over the tumor ingrowth in the uncovered biliary stent.