ERCP (Endoscopic Retrograde Cholangio-Pancreatography)
What ERCP is all about?
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, 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 is flexible and can be directed and moved around the many bends of the stomach and intestine.
Two types of duodenoscopes are currently available:
- A fiber-optic duodenoscope uses a thin fiber-optic bundle to transmit images to the lens at the viewing end of the instrument.
- A videoscope uses a thin wire with a chip at the tip of the instrument to transmit images to a TV screen. The duodenoscope is inserted through the mouth, to the back of the throat, down the food pipe, through the stomach and into the first portion of the small intestine (duodenum). Once the papilla of Vater is identified, a small plastic catheter (cannula) is passed through an open channel of the duodenoscope into the papilla of Vater, 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. The open channel also allows other instruments to be passed through it in order to perform biopsies, to insert plastic or metal tubing to relieve obstruction of bile ducts caused by cancer or scarring, and to perform incision 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 also produces digestive juice which drains through the pancreatic duct into the papilla of Vater, and into the intestine.
What kind of preparation is required?
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 liquid should be taken. In case the examination is performed at noon time, a cup of tea, juice, milk, or coffee can be taken 4 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, the patient needs to have a companion drive him/her home after the procedure.
What are the reasons for 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:
- Confirming the diagnosis of cancer of the pancreas or the bile duct, so that surgery or other treatment can be tailored
- Gallstones in the bile duct
- Unexplained loss of appetite and weight loss
- Persistent or recurrent upper abdominal pain which cannot be diagnosed by other tests
- Blockage of the bile duct by stones, cancer, stricture or compression from adjacent organs
- Jaundice (yellow coloring of the skin) due to obstruction of the bile duct, also causing darkening of the urine and light colored stool.
What can be expected during and after the procedure?
The patient will be given medication 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 medication for sedation. This also applies to those patients who have a history of allergy to Xylocaine, cannot tolerate the bitter taste of the local anesthetic, or 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 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.
When the patient is in semi-conscious state, he/she can still follow instructions to change the position on the x-rays 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 and the anatomy or abnormalities in that area.
After the procedure, the patients should be observed in the recovery area until most of the effects from the medication have worn off. This usually takes one to two hours. The patient may feel bloated or slightly nauseated from the medication 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 his/her 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 to the patient or companion regarding the findings after the procedure, it is still necessary to call the physician the next day to ensure that the patient understands the results of the examination.
What are the side effects and risks of the procedure?
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. 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 and can occur even in very experienced physicians. This pancreatitis “injection “ usually is treated in the hospital for one to two days. Another possible complication is infection. Other serious risks including perforation of the bowel, drug reactions, bleeding, depressed breathing, irregular heart beat or heart attack are extremely rare. In case of complication, patient needs to be hospitalized and surgery is rarely required.