Article: Endoscopic retrograde cholangiopancreatography

Introduction

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. It is essentially an X-ray image of the bile ducts and pancreatic duct(s). It was invented by Dr. Richard Kozarek, a gastroenterologist with Virginia Mason Clinic in Seattle.

Indications

ERCP may be performed for diagnostic or therapeutic reasons.

Diagnostic

• Obstructive jaundice - This may be due to several causes
• Chronic pancreatitis
• Gallstones with dilated bile ducts on ultrasonography
• Pancreatic/Bile duct tumors
• Suspected injury to bile ducts either as a result of trauma or iatrogenic

Therapeutic

• Any of the above when the following may become necessary
  • Sphincterotomy
  • Removal of stones
  • Insertion of stent

Procedure

The patient is often 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 leakage of bile into the peritoneum (the abdominal cavity).

A wire and balloon may be passed into the bile duct, then inflated in order to expand the opening of the bile duct to allow passage of gallstones. When needed, the opening of the ampulla can be enlarged with an electrified wire (sphincterotome) and access into the bile duct obtained so that gallstones may be removed or other therapy performed.

Other procedures associated with ERCP include the trawling of the common bile duct with a basket or balloon to remove gallstones and the insertion of a plastic stent to assist the drainage of bile. Also, the pancreatic duct can be cannulated and stents be inserted. The pancreatic duct requires visualisation in cases of pancreatitis.