What happens during ERCP and why they are used
ERCP is short for Endoscopic Retrograde CholangioPancreatogram.
Diagnostic ERCP is when X-ray contrast dye is injected into the bile duct, the pancreatic duct, or both and X-rays are taken to get pictures of these ducts. Because the ERCP is an invasive procedure, it is usually only carried out if there will also be some therapeutic value to the patient.
ERCP allows examination of the tubes that drain the liver and pancreas. It is mainly used to study these areas and then conduct a therapeutic procedure in narrowed or obstructed tubes. It may be used to treat jaundice, episodes of cholangitis or ascending cholangitis, significant increases in your bilirubin, to remove stones, insert stents and clear blockages.
ERCPs should be carried out after expert clinico-radiological assessment to justify the procedure.
Dominant biliary strictures develop in up to 50% of patients with PSC. This is where the common bile duct narrows to less than 1.5mm or less than 1mm in a hepatic duct. Sometimes, dominant strictures can lead to complications such as jaundice, cholangitis and itch or deterioration in liver biochemistry, in which case ERCP may be performed 131. Dominant strictures can be balloon dilated at ERCP (see below).
What happens in an ERCP?
ERCP is usually carried out under sedation: this means you will be relaxed but not completely asleep. You may be able to go home when you have recovered from the procedure but some people remain in hospital overnight to be monitored.
- Patients receive a local anaesthetic that is gargled or sprayed on the back of the throat; this anaesthetic numbs the throat.
- A needle is inserted into a vein in the arm if sedatives are to be given. You will be monitored throughout the procedure.
- During an ERCP, you will lie on your back or side on an X-ray table.
- The doctor inserts an endoscope (thin flexible tube) through the mouth, down the oesophagus, through the stomach, and into the duodenum. Video is transmitted from a small camera attached to the endoscope to a computer screen. Air is pumped through the endoscope to inflate the stomach and duodenum, making them easier for the doctor to examine.
- During the ERCP, biliary stenting or balloon dilatation can take place, which has been shown to improve the liver biochemistry/symptoms 131. Balloon dilatation should be the initial treatment of choice for dominant strictures in patients with PSC, as they are associated with less complications that stent dilatation 132.
When a narrowing of the bile ducts is discovered, a short tube (a stent) can be inserted. This will open the bile duct and allow the bile to drain. The tubes do not last forever and over time can become blocked, at which point the procedure may be repeated.
Strictures (narrowing) within the liver may not be appropriate for stenting because they are not easily accessible.
Balloon dilation is another option if a narrowing of the bile ducts is discovered. A tiny tube with a balloon on the end is inserted into the bile duct. At the narrowing (stricture), the balloon is inflated and deflated several times to expand the duct so the bile can flow through once more. Because the bile ducts can sometimes quickly return to their narrowed state, sometimes a stent is placed at the stricture point.
When the doctor has located the correct position, dye is injected into the bile ducts, allowing them to be seen on X-rays. X-rays are then taken to show the ducts and to look for narrowed areas or blockages.
After the ERCP
Following the procedure, you will be monitored to see when it is appropriate for you to go home, and you must have someone with you for 24 hours. Some patients experience abdominal discomfort or bloating because of the air that was pumped into them. In some cases, patients may suffer attacks of pancreatitis or cholangitis. If there are any complications, you will remain in hospital following the procedure.
Complications following ERCP
Cholangitis flares and pancreatitis can occur following ERCP, so current guidelines recommend antibiotics are given prior to the procedure taking place as a precautionary measure 67 and for 5-7 days after the procedure.
People who have an ERCP are likely to have another one in the future. It is important that you discuss this procedure carefully with your consultant and understand the complications that may arise. Most people suffer little discomfort and complications following this procedure.
The role of ERCP in PSC
Dr Roger Chapman talks to patients at our 2016 Oxford Information Day about ERCPs, covering what strictures are, MRCPs, ERCPs, risks, what ERCPs are used to do including stents and balloon dilatation.