LAUSR

A 77-year-old woman was admitted to our hospital with jaundice. Contrast-enhanced computed tomography revealed a tumor in the pancreatic head with distal biliary obstruction (▶Fig. 1). The aorta and inferior mesenteric artery (IMA) were distorted to the right by severe scoliosis, which caused the IMA to run close to the tumor and the papilla of Vater (▶Fig. 2). Endoscopic retrograde cholangiopancreatography (ERCP) was performed for biliary drainage (▶Video 1). On ERCP, a guidewire was unintentionally inserted into the IMA and the aorta (▶Fig. 3). However, we were unable to recognize the insertion of the guidewire into the artery because of the similarity between the course of the aorta and the bile duct (▶Fig. 2, ▶Fig. 3). The passage of the catheter across the papilla along the guidewire was difficult because of the resisting force of the arterial wall, and was finally achieved by pushing the catheter repeatedly. Arterial blood, in which the partial pressure of oxygen was 151mmHg, was collected using syringe suction via the catheter lumen. Pulsatile bleeding from the papilla was observed immediately after the catheter was removed (▶Fig. 4). Hemostasis was successfully achieved by compression for a few minutes using a balloon catheter. Seven days later, the patient underwent biliary drainage with endoscopic ultrasound-guided choledochoduodenostomy. Although arterial cannulation is a very rare complication of ERCP [1, 2], it can be critical because of the massive bleeding. In the present case, for example, if we E-Videos