Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
The procedure is performed by using a long, flexible, viewing instrument (a duodenoscope) about the diameter of a pen. The duodenoscope can be directed and moved around the many bends of the stomach and duodenum. The modern duodenoscope uses a thin fiber-optic bundle to transmit light to the tip of the endoscope, and a thin wire with a chip also at the tip of the endoscope to transmit digital video images to a TV screen. The duodenoscope is inserted through the mouth, through the back of the throat, down the food pipe (esophagus), through the stomach and into the duodenum. Once the papilla of Vater is identified, a small plastic catheter (cannula) is passed through an open channel of the endoscope into the opening of the papilla, and into the bile ducts and/or the pancreatic duct. Contrast material (dye) is then injected and
X-rays are taken of the bile ducts and the pancreatic duct. An open channel in the endoscope also allows other instruments to be passed through it in order to perform biopsies, to insert plastic or metal tubing to relieve obstruction of the bile ducts
or pancreatic duct caused by cancer or scarring, and to perform incisions by using electrocautery
The liver is a large solid organ located beneath the right diaphragm. The liver produces bile, which is stored in the gallbladder (a small sac located beneath the liver). After meals, the gallbladder contracts and empties the bile through the cystic duct, into the bile ducts, through the papilla of Vater, and into the intestine to help with digestion. The pancreas is located behind the stomach. It produces a digestive juice that drains through the pancreatic duct--which usually joins the bile duct within the papilla,--and then enters the intestine.
An important procedure related to ERCP is endoscopic ultrasonography which uses a similar endoscope that, in addition to the camera, has an ultrasound probe on its tip to examine the bile ducts, gallbladder, pancreatic duct, and pancreas ultrasonographically. Ultrasonographically-directed needle biopsies of the pancreas can be taken through a channel in the endoscope.
A second, newer procedure related to ERCP is the use of miniature endoscopes that are passed through the operating channel of a duodenoscope and can be inserted directly into the bile and pancreatic ducts. The inside of the ducts can be visualized, and directed biopsies can be taken. Other therapeutic interventions also are possible.
Picture of the upper GI system, gallbladder, liver, and pancreas