CLINICAL ASSOCIATE PROFESSOR, SYDNEY UNIVERSITY
GASTROENTEROLOGIST AND THERAPEUTIC ENDOSCOPIST
CHAIRMAN OF ENDOSCOPY, GASTROENTEROLOGY
SOCIETY OF AUSTRALIA
What is ERCP?
Endoscopic retrograde cholangiopancreatography, or ERCP, is a specialised technique used to study the ducts of the gallbladder, pancreas and liver. Ducts are drainage routes; the drainage channels from the liver are called bile or biliary ducts. If your doctor has recommended an ERCP, this information sheet will give you a basic understanding of the procedure - how it's performed, how it can help, and what side effects you might experience. Please ask you doctor about anything you don't understand.
During ERCP, your doctor will pass an endoscope through your mouth, oesophagus and stomach into the duodenum (first part of the small intestine). An endoscope is a thin, flexible tube that lets your doctor see inside your bowels. After your doctor sees the opening to ducts from the liver and pancreas, your doctor will pass a narrow plastic tube called a catheter through the endoscope and into the ducts. Your doctor will inject a contrast material (dye) into the pancreatic or biliary ducts and will take X-rays. Most patients require some therapy during ERCP such as stone removal or plastic stents (tube) insertions to unblock narrowings.
What preparation is required?
You should fast for at least six hours (and preferably overnight) before the procedure to make sure you have an empty stomach, which is necessary for the best examination. Your doctor will give you precise instructions about how to prepare.
You should talk to your doctor about medications you take regularly and any allergies you have to medications, or intravenous contrast material. Although an allergy doesn't prevent you from having ERCP, it's important to discuss it with your doctor prior to the procedure. Also, be sure to tell your doctor if you have any major diseases.
What can I expect during ERCP?
Your doctor might apply a local anaesthetic to your throat before giving you a sedative to make you more comfortable. Some patients also receive antibiotics before the procedure. You will lie on your abdomen on an X-ray table. Your doctor will pass the endoscope through your mouth, oesophagus, stomach and into the duodenum. The instrument does not interfere with breathing, but you might feel a bloating sensation because of the air introduced through the instrument.
What are possible complications of ERCP?
ERCP is a well-tolerated procedure when performed by doctors who are specially trained and experienced in the technique. Complications or side-effects requiring hospitalization occur about 1 in 20 patients. Risks vary, depending on why the test is performed, what is found during the procedure, what therapeutic intervention is undertaken, and whether a patient has major medical problems. They are usually minor and resolve within 2-3 days. Complications can include pain, infections (these can rarely be severe and life threaghtening), pancreatitis (an inflammation or infection of the pancreas) and bleeding. It is rare to have more severe complications such as perforation however if any symptoms develop please inform the doctor to manage the problem immediately. Sometimes the procedure cannot be completed for technical reasons and may need an additional procedure.
In recent years new resistant bugs can grow in these endoscopes and infections can be introduced into patients and these infectious can be very severe. Australian cleaning standards are high and cross infection is rare.
What can I expect after ERCP?
If you have ERCP, you will be observed for complications until most of the effects of the medications have worn off. You might experience bloating or pass gas because of the air introduced during the examination. All patients should remain on a liquid diet until the day after the procedure and can resume normal diet if they are well.
Someone must accompany you home from the procedure because of the sedatives used during the examination. Even if you feel alert after the procedure, the sedatives can affect your judgment and reflexes for the rest of the day.
What is a therapeutic ERCP?
Most ERCPs are actually done for treatment and not just taking pictures. When an ERCP is done to allow treatment, it is called therapeutic ERCP. The types of treatment are outlined below.
What treatments can be done through an ERCP scope?
Sphincterotomy is cutting the muscle that surrounds the opening of the ducts, or the papilla. This cut is made to enlarge the opening. Usually, a sphincterotomy does not cause discomfort, you do not have nerve endings there. The actual cut is quite small, usually less than a 1/2 inch. This small cut, or sphincterotomy, allows various treatments in the ducts.
The most common treatment through an ERCP scope is removal of bile duct stones. These stones may have formed in the gallbladder and traveled into the bile duct or may form in the duct itself years after your gallbladder has been removed. After a sphincterotomy is performed to enlarge the opening of the bile duct, stones can be pulled from the duct into the bowel. A variety of balloons and baskets attached to specialized catheters can be passed through the ERCP scope into the ducts allowing stone removal. Very large stones may require crushing in the duct with a specialized basket so the fragments can be pulled out through the sphincterotomy.
Stents are placed into the bile or pancreatic ducts to bypass strictures, or narrowed parts of the duct. These narrowed areas of the bile or pancreatic duct are due to scar tissue or tumors that cause blockage of normal duct drainage. There are two types of stents that are commonly used. The first is made of plastic and looks like a small straw. The second type of stent is made of metal wires that looks like the cross wires of a fence. The metal stent is flexible and springs open to a larger diameter than plastic stents. Both plastic and metal stents tend to clog up after several months and you may require another ERCP to place a new stent. Your doctor will choose the best type of stent for your problem.
There are ERCP catheters fitted with dilating balloons that can be placed across a narrowed area or stricture. The balloon is then inflated to stretch out the narrowing. After balloon dilation, a temporary stent may be placed for a few months to help maintain the dilation.
One procedure that is commonly performed through the ERCP scope is to take samples of tissue from the papilla or from the bile or pancreatic ducts. There are several different sampling techniques although the most common is to brush the area with subsequent examination of the cells obtained. Tissue samples can help decide if a stricture, or narrowing, is due to a cancer. If the sample is positive for cancer it is very accurate. Unfortunately, a tissue sampling that does not show cancer may not be accurate.
There are several types of ERCP cases which are very difficult. These include patients with previous surgery altering their anatomy so access to the bile duct is only possible using different instruments. These situations are rare but require a prolonged procedure with additional risks. There are also cases where a miniature camera is inserted through the endoscope into the bile or pancreas duct to increase our ability to view and treat problems inside the ducts.
Two plastic stents inserted into the bile duct
The opening of the bile duct is very small and is seen below between the black arrows.