What is it, and what is it for?
An ERCP test, or ‘Endoscopic Retrograde Cholangio-Pancreatography’ test, is a specialised camera test of the ducts that drain the liver (‘bile ducts’) and pancreas (‘pancreatic duct’). It involves passing a flexible telescope through the mouth, down the gullet and through the stomach to the first part of the small bowel (‘duodenum’) into which these ducts drain. Images of the ducts can then be obtained using x-ray, and wires, baskets, balloons or stents can be passed through the camera to remove gallstones or alleviate benign or cancerous blockages. Bile drainage can be improved by placing a small cut through the bottom of the bile duct (‘sphincterotomy’). Tissue samples (’biopsies’) or fluid (‘cytology’) can also be taken for analysis. The test takes around 30-45 minutes and is done under heavy sedation or a light general anaesthetic. Patients are kept overnight and discharged the following day.
What are the alternatives?
ERCP is the least invasive way to alleviate blockages in the biliary system or pancreas. The alternative is major surgery which carries considerably more risk. Good images of this part of the anatomy can be obtained using magnetic resonance imaging (‘MRCP’ test) but an ERCP test would still be required to take tissue samples or to alleviate blockages.
Is there anything I need to do before the test?
It is very important that the stomach is clear or food prior to an ERCP. For most people a six hour fast (both food and drink) is all that is required – for a morning procedure you should take nothing by mouth from midnight the night before. For an afternoon procedure you can take an early (7am) light breakfast and then nothing by mouth until after. If you take warfarin or clopidogrel (blood thinners), or are diabetic, the doctor will give you some specific advice when you see him in clinic about what to do with your tablets.
What will I feel during the test?
The test is performed with local anaesthetic spray to the back of the throat in addition to heavy sedation and a painkiller injection, or a light general anaesthetic, given by a needle in the arm. An anaesthetist will be present throughout the procedure to ensure that you are safe and comfortable, and it is unlikely that you will remember anything about the test afterwards.
What happens after the test?
If you have had heavy sedation you may feel drowsy for an hour or two after the test. Although you may feel normal after this the drugs are still in your system for 24 hours and you should not drink alcohol, drive a car, go swimming, sign legal documents etc. within this period. If you have had a light general anaesthetic you will wake up quickly, should not feel drowsy and should be safe to drive the following day. You may feel bloated after the test – this passes fairly quickly. You will be allowed to drink clear fluids when you are fully awake, but it is safest to wait until 4 hours after the test before you take anything to eat.
Are there any risks?
Because ERCP is not just a diagnostic test but is used to perform therapy on the biliary and pancreatic system, it does carry more risk than other forms of endosocpy. However it is still by far the safest method of treating biliary and pancreatic disorders. A common problem is a sore throat, caused by retching during the procedure, which usually wears off within 24-48 hours. The main serious complication following an ERCP test is inflammation of the pancreas (‘pancreatitis’) which may occur in up to 3 or 4 out of every 100 procedures. This would be suspected if there is worsening central abdominal pain following the test. If it occurs it is usually mild and settles with bowel rest within 24-48 hours. In a small proportion it can be severe or even potentially life threatening. As with other forms of endoscopy, damage (‘perforation’) to the back of the throat, gullet, stomach or small bowel can occur, but is rare, occurring no more than one in every several hundred procedures. A perforation might be suspected if there is significant pain following the procedure which is not getting better. If suspected, a chest x-ray or CT scan would be performed, and the patient may be kept in hospital overnight. If confirmed, an operation may be required although a small perforation may seal itself with gut rest and antibiotics. There is a small risk of bleeding following ERCP if a sphincterotomy has been performed (see earlier), but significant bleeding may occur in only one in every several hundred procedures.