Endoscopic retrograde cholangiopancreatography (ERCP) is a technique that combines the use of endoscopy and fluoroscopy to diagnose and treat certain problems of the biliary or pancreatic ductal systems. Through the endoscope, the physician can see the inside of the stomach and duodenum, and inject radiographic contrast into the ducts in the biliary tree and pancreas so they can be seen on X-rays. ERCP is used primarily to diagnose and treat conditions of the bile ducts and main pancreatic duct, including gallstones, inflammatory strictures (scars), leaks (from trauma and surgery), and cancer. ERCP can be performed for diagnostic and therapeutic reasons, although the development of safer and relatively non-invasive investigations such as magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound has meant that ERCP is now rarely performed without therapeutic intent.
The patient is sedated or anaesthetized. Then a flexible camera (endoscope) is inserted through the mouth, down the esophagus, into the stomach, through the pylorus into the duodenum where the ampulla of Vater (the opening of the common bile duct and pancreatic duct) exists. The sphincter of Oddi is a muscular valve that controls the opening of the ampulla. The region can be directly visualized with the endoscopic camera while various procedures are performed. A plastic catheter or cannula is inserted through the ampulla, and radiocontrast is injected into the bile ducts and/or pancreatic duct. Fluoroscopy is used to look for blockages, or other lesions such as stones.
When needed, the opening of the ampulla can be enlarged (sphincterotomy) with an electrified wire (sphincterotome) and access into the bile duct obtained so that gallstones may be removed or other therapy performed.