Methods of tissue sampling Antibiotics will be administered intravenously 30 minutes before ERCP. ERCP with biliary decompression will be performed with standard techniques. 2 After bile duct cannulation, iopromide (Ultravist, 300mgI/mL, Berlex, Montville, N.J.) will be injected, and the level and length of the biliary stricture will be determined. A guidewire will be passed through the stricture and intrahepatic opacification will be completed. A biliary sphincterotomy will be performed using a standard sphincterotome, to facilitate placement of a stent or of a naso-biliary drain. Pancreatography will possibly be attempted, especially if pancreatic disease is suspected.