Penetration of duodenal wall by proximal end of biliary straight plastic stent in a patient with ampullary carcinoma.

A 70-year-old woman presented to our hospital with abdominal discomfort. Gastrointestinal endoscopy revealed an ampullary tumor, while a biopsy revealed a pathological diagnosis of adenocarcinoma. No distant metastases were observed and neoadjuvant chemotherapy and surgical resection were planned. Shortly thereafter, she developed obstructive jaundice due to the ampullary carcinoma. The patient underwent endoscopic retrograde cholangiopancreatography, during which a straight plastic stent was placed in the bile duct. The patient was discharged without complications. Neoadjuvant chemotherapy was initiated. Two months later, she was readmitted for surgery while asymptomatic. Endoscopic retrograde cholangiopancreatography was scheduled to replace the stent with a nasobiliary drainage tube for the surgery. Endoscopic imaging revealed that the proximal end of the stent had penetrated the duodenum on the oral side of the ampullary carcinoma. The distal end of the stent was grasped with forceps and the stent was successfully removed. A catheter was inserted into the bile duct orifice and cholangiography was performed, which revealed that the distal bile duct and the duodenum had formed a fistula. A guidewire was placed in the bile duct via the papilla and a nasobiliary drainage tube was placed. After endoscopic retrograde cholangiopancreatography, the patient exhibited smooth progress without issue. Pancreaticoduodenectomy was performed on the fourth day after the nasobiliary drainage tube placement, and the patient's postoperative course was uneventful. The proximal end of a biliary stent penetrating the duodenal wall is an infrequent phenomenon. This case report highlights a rare but noteworthy adverse event associated with straight biliary plastic stent placement.