Active_comparator: US-guided percutaneous biliary drainage

The initial percutaneous transhepatic puncture of the bile duct is performed by ultrasound guidance with a Chiba-needle (0.7 mm). After injection of a radiopaque contrast media into the bile duct system, the malignant extrahepatic bile duct stenosis can be visualized by fluoroscopic guidance (digital remote-controlled fluoroscopy device). Then a 0.018 inch guide wire is introduced and proceeded beyond the tumor stenosis into the duodenum. Next, the Chiba needle is exchanged by a 5 F catheter and the 0.018 inch guide wire is exchanged by a 0.035 inch guide wire. After dilatation of the hepatic access route with bougies up to 12 F, a self-expandable metal stent is introduced. The placement of the metal stent is controlled by endoscopic luminal guidance (gastroscope or duodenoscope).

Experimental: EUS-guided biliary drainage

The initial transluminal puncture of the bile duct is performed by endoscopic ultrasound guidance (longitudinal echoendoscope) with an 19 G access needle. After injection of a radiopaque contrast media into the bile duct system, the malignant extrahepatic bile duct stenosis can be visualized by fluoroscopic guidance. Then, a 0.035 inch guide wire is introduced into the bile duct. After dilatation of the transluminal access route with a balloon catheter, a self-expandable metal stent is introduced as an antegrade biliary drainage, a transhepatic biliary drainage or a choledochal biliary drainage. The placement of the metal stent is controlled by fluoroscopic and endoscopic luminal guidance.