• ERCP is a diagnostic procedure designed to examine diseases of the liver, bile ducts and pancreas.
• ERCP is usually best performed under general anesthesia. It may be done using IV sedation.
• There is a low incidence of complications.
• ERCP can provide important information that cannot be obtained by other diagnostic examinations, for example, abdominal ultrasound, CT scan, or MRI.
• Frequently, therapeutic measures can be performed at the time of ERCP to remove stones in the bile ducts or to relieve obstruction of the bile ducts.

Endoscopic retrograde cholangio-pancreatography (ERCP) is a diagnostic test to examine:

•  the duodenum (the first portion of the small intestine),
• the papilla of Vater (a small nipple-like structure with openings leading to the bile ducts and the pancreatic duct),
• the bile ducts, and
• the gallbladder and the pancreatic duct.

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. Another open channel in the endoscope also allows other instruments to be passed through it in order to perform biopsies, to insert plastic or metal stents or tubing to relieve obstruction of the bile ducts or pancreatic duct caused by cancer or scarring, and to perform incisions by using electrocautery (electric heat).

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 (Spyglass) 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 (Spybite) can be taken. Other therapeutic interventions also are possible.

Picture of the upper GI system, gallbladder, liver, and pancreas

For the best possible examination, the stomach must be empty. The patient should not eat anything after midnight on the evening preceding the exam. In case the procedure is performed early in the morning, no liquids should be taken. In case the examination is performed at noon time, a cup of tea, juice, milk, or coffee can be taken eight hours earlier. Heart and blood pressure medications should always be taken with a small amount of water in the early morning. Since the procedure will require intravenous sedation or general anesthesia, the patient needs to have a companion drive them home after the procedure.

If done with IV sedation, the patient will be given medications through a vein to cause relaxation and sleepiness. The patient will be given some local anesthetic to decrease the gag reflex. Some physicians do not use local anesthetic and prefer to give the patients more intravenous medications for sedation. This also applies to those patients who have a history of allergy to Xylocaine or cannot tolerate the bitter taste of the local anesthetic and the numbness sensation in the throat. While the patient is lying on the left side on the X-ray table, the intravenous medication is given, and then the instrument is inserted gently through the mouth into the duodenum. The instrument advances through the food pipe and not the air pipe. It does not interfere with the breathing and gagging is usually prevented or decreased by the medication. If using general anesthesia, then the above procedure does not apply.

When the patient is in  a semi-conscious state, they can still follow instructions such as changing the body position on the X-ray table. Once the instrument has been advanced into the stomach, there is minimal discomfort except for the foreign body sensation in the throat. The procedure can last anywhere from fifteen minutes to one hour, depending on the skill of the physician, what needs to be accomplished, and the anatomy or abnormalities in that area. ERCP also may be performed under light, general anesthesia.

After the procedure, patients should be observed in the recovery area until most of the effects from the medications have worn off. This usually takes one to two hours. The patient may feel bloated or slightly nauseated from the medications or the procedure. Very rarely a patient experiences vomiting, and may belch or pass some gas through the rectum. Upon discharge, the patient should be driven home by a companion and is advised to stay home for the rest of the day. The patient can resume usual activity the next day. Even though the physician may explain he findings to the patient or companion after the procedure, it is still necessary to follow up with the physician after the procedure to ensure that the patient understands the results of the examination.

The liver, bile ducts, gallbladder, pancreas and the papilla of Vater can be involved in numerous diseases, causing myriad of symptoms. ERCP is used in diagnosing and treating the following conditions:

• Blockage of the bile duct by gallstones, cancer, strictures (scarring) or compression from adjacent organs or tumors
• Jaundice (yellow coloring of the skin) due to obstruction of the bile duct, also causing darkening of the urine and light colored stool.
• Persistent or recurrent upper abdominal pain which cannot be diagnosed by other tests such as MRCP/MRI, CT
• Confirming the diagnosis of cancer of the pancreas or the bile duct, so that surgery or other treatment can be tailored to the disease
• When there is suspicion that the Sphincter of Oddi within the Papilla of Vater, that controls the flow of bile and pancreatic juice, is not working normally (Sphincter of Oddi dysfunction)

ERCP is a highly specialized procedure which requires a lot of experience and skill. The procedure is quite safe and is associated with a very low risk when it is performed by experienced physicians. The success rate in performing this procedure varies from 70% to 95% depending on the experience of the physician. Complications can occur in approximately one to five percent depending on the skill of the physician and the underlying disorder. The most common complication is pancreatitis which is due to irritation of the pancreas from the dye used to take pictures and can occur even with very experienced physicians. This "injection" pancreatitis usually is treated in the hospital for one to two days. Another possible complication is infection. Other serious risks including perforation of the intestine, drug reactions, bleeding, depressed breathing. Irregular heart beat or heart attack are extremely rare and is mainly due to the sedation. In case of complications, patients usually need to be hospitalized, but surgery rarely is required.

In summary, ERCP is a straight-forward but skill-requiring outpatient examination that is performed with the patient sedated under IV sedation or general anesthesia. The procedure provides important information upon which specific treatment can be tailored. In certain cases, therapy can be performed at the same time through the duodenoscope, so that traditional open surgery can be avoided. ERCP, combined with endoscopic ultrasonography, is currently the diagnostic and therapeutic procedure of choice in most patients for identifying and removing gallstones in the bile ducts.