ERCP, also known as Endoscopic Retrograde Cholangio Pancreatography, is a procedure to examine the anatomy of the ducts draining the liver and pancreas. This includes the bile ducts, gallbladder, and pancreatic ducts. ERCP is useful in determining whether or not there are gallstones in the bile ducts, cancer involving the bile ducts or pancreas, as well as a number of other conditions. The ERCP endoscope also allows removal of gallstones from the bile ducts, dilating strictures, or placing stents across blocked ducts to hold them open, all without surgery. Stenting a duct may give immediate relief of a malignant obstruction as seen in pancreatic cancer for example.
Pictured left are Sequential shots of the ampulla bulging with an impacted stone, opening of the ampulla with a sphincterotome, and removal of first two, than multiple bile duct stones with a balloon.
Pictured right is a stent protruding from the bile duct into the duodenum.
How is it Done?
ERCP is a combined endoscopic and radiologic procedure. It is performed in an X-ray suite with the patient positioned lying prone(on the abdomen) on the x-ray table. No special preparation is required other than an overnight fast. Sedation is administered to remove any discomfort and provide complete relaxation. A duodenoscope is inserted through the mouth into the upper part of the small intestine to locate the area where the bile ducts and pancreatic ducts drain their contents into the intestine. This spot is known as the ampulla of Vater. An enlarged ampulla is pictured in the preceding paragraph. A catheter or small tube is then fed through the scope and threaded up through the ampulla into the bile ducts and the pancreatic ducts. X-ray contrast is then injected though the catheter filling the ducts. At this point, the x-ray machine is turned on and the ducts filled with contrast show up clearly on the x-ray screen, as in the images below, which depict the normal bile and pancreatic ducts.
The larger tube is the scope. Once the anatomy is clearly delineated further intervention may be indicated. A stone is removed by placing a catheter with a wire into the duct and applying an electrical charge to heat the wire and make a small incision through the ampulla. This technique, known as a sphincterotomy, allows a balloon or basket to be inserted up into the duct where a stone may be grasped, crushed, or simply pulled out through the enlarged opening. Other devices such as plastic or metal stents may be placed to provide drainage through a blocked opening, usually caused by a malignant stricture. The four radiographs below demonstrate, a stone in the bile duct, multiple stones in the bile duct, a balloon inflated in the bile duct, and a malignant stricture of the pancreatic duct.
How will I Feel?
During the ERCP, you will be given sedatives to relax and a painkiller to minimize any discomfort. Occasionally, an anesthesiologist may assist, but usually the nurse closely monitors blood pressure, oxygen level, heart rate, and comfort level. Medicine is administered as needed throughout the examination. After the exam, the medicine will quickly wear off and you will feel slightly bloated or distended from air that was used to inflate the intestine during the procedure. You may have a slight sore throat or mild abdominal discomfort. If an intervention such as a sphincterotomy is performed, you will be asked to remain in the hospital for several hours and in some cases overnight. This observation period is for your safety. Rarely, these interventions may lead to bleeding or perforation of the bowel. Slightly more frequently is the complication of pancreatitis. This condition results in inflammation of the pancreas and may require a few days hospitalization to settle down. The observation period following the ERCP allows your doctor to assess when it is safe to discharge you. Once you are home you should take it easy the day of the procedure because of the sedatives. NO Driving for 24 hours after the sedatives are administered. Following this, you should be back to normal activity.
What are the Alternatives?
The liver, bile ducts and pancreas may be imaged with a variety of techniques. Ultrasound is the easiest and least expensive, but often does not give an accurate indication of what is going on in the ducts. CT scan depicts the liver and pancreas quite well but may not be able to pick up subtle changes in the ducts of both glands. MRI has been useful in picturing the ducts of the pancreas and biliary tree when done at experienced centers. Usually, several of these exams are performed prior to making a decision to go ahead with ERCP. ERCP is then performed to confirm what is suspected or to perform an intervention such as removal of bile duct stones. ERCP is considerably less invasive than surgery for removal of stones, and is now often combined with laparoscopic gallbladder surgery to allow patients a more rapid recovery than the extensive surgery of prior years.
What are the Risks?
As noted above, there are some potential complications from this procedure. Pancreatitis, inflammation of the pancreas, may occur due to manipulation of the ducts with the catheter. Bleeding and perforation of the bowel or bile duct may occur associated with sphincterotomy, positioning the scope, or other manipulation of the biliary and pancreatic ducts. Complications indirectly tied to the procedure are soreness or infection at the IV site, or adverse reaction to the sedatives. This is considered a relatively safe procedure that can usually be performed as an out patient but awareness of these potential complications is essential.