Endoscopic ultrasound directed transgastric ERCP (EDGE)

ERCP stands for endoscopic retrograde cholangiopancreatography. ERCP is done using a thin, flexible camera (called an endoscope) which is inserted into the mouth along the oesophagus (food pipe) and stomach and into the top part of the small bowel (duodenum).

A wire is used to access the bile duct and pancreatic ducts under X-ray guidance. Instruments can be passed through the bile duct using the wire as a guide. Dye which shows up on X-rays can then be injected into the bile ducts to identify any  abnormalities such as gallstones or strictures (narrowings). This allows a range of procedures to be performed if needed, such as taking samples (biopsies), placing drainage tubes (stents) to relieve a blockage or to remove gallstones.

Patients who have had gastric bypass surgery cannot have a traditional ERCP. This is because gastric bypass surgery changes the way food passes through the gut. During gastric bypass surgery a connection is made between the top part of the stomach and a lower part of the small bowel. Most of the stomach and all of the duodenum are bypassed. This means it is not possible to pass an endoscope through the oesophagus and stomach into the duodenum in order to access bile duct and pancreatic ducts.

Endoscopic ultrasound directed transgastric ERCP (also known as EDGE) is another way of doing an ERCP for patients who have had gastric bypass surgery. The procedure is usually done for patients who need treatment for gallstones which are blocking the bile duct, causing pain and infection.

An EDGE procedure is done in three stages. The first two stages can be done at the same time. The procedure is done under general anaesthetic.

Stage 1 – endoscopic ultrasound (EUS)

An endoscope with an ultrasound probe on the end is passed into the top part of the stomach. The endoscope is then used to place a short metal tube (called a stent) between the two parts of the stomach which had been separated during gastric bypass surgery. This endoscope is then removed.

Stage 2 – ERCP

A different sort of endoscope is passed into the top part of the stomach, through the stent into the bypassed part of the stomach and into the duodenum. The bile duct can then be accessed and an ERCP can be done in the same way as a standard ERCP.

If done together, stages 1 and 2 take around one to two hours.

Stage 3 – stent removal

After several weeks the stent is removed. An endoscope with a tiny pair of forceps on the end is passed into the top part of the stomach. The forceps are used to pull out the stent.

It is very likely that the hole which is left will close over on its own. If the hole has not closed off or become very small, another endoscopy procedure can be done to close the hole with clips or stitches.

All treatments and procedures have risks. We will talk to you about the risks of EDGE in more detail in outpatient clinic
before your procedure.

Complications of any stage of EDGE

Unusual complications which can occur during any procedure that uses endoscopy include:

• chest infections
• a hole (perforation) or tear in the wall of the oesophagus, stomach or duodenum
• allergy to sedative medication
• bleeding
• damage to teeth.

Complications of Stage 1 (EUS)

There are also specific risks which can occur during or after
EDGE.

• bleeding. Rarely, if bleeding continues and is severe, a patient may need a blood transfusion or a separate procedure to stop the bleeding.
• wrongly placed stent. It is possible that the stent will fail to make a connection between the two parts of the stomach. If this happened you would need a surgical procedure in operating theatres to repair the stomach and small bowel. Whilst this risk is possible in theory, it is very unlikely to occur.
• weight gain. If you have had gastric bypass surgery for weight loss it is possible that you may put on weight. This is because a connection is made between the parts of the stomach which had been separated during the gastric bypass operation. However the evidence suggests that this does not actually happen. After several weeks the connection is closed during the endoscopy procedure to remove the stent.

Complications of Stage 2 (ERCP)

Complications specific to ERCP include:

• inflammation of the pancreas (pancreatitis). Certain measures may reduce the risk of pancreatitis (e.g. an antiinflammatory suppository), and these may be discussed with you during the consent process. Although pancreatitis is always unpleasant and may require a longer stay in hospital, on rare occasions it can be fatal.
• bleeding, usually if a cut of the sphincter at the lower end of the bile duct has been performed).
• infection within the bile duct (cholangitis). These complications usually settle down by themselves, but may require a longer stay in hospital, and may require urgent treatment (very occasionally this can mean surgery).

The risk of having a complication is generally 5-10%, but certain indications and interventions during ERCP may increase the risk (up to 20%). The chance of dying within thirty days of having an ERCP is about one in two hundred (0.5%). Most deaths result from an underlying medical problem but there is a very small risk of death from a direct complication of an ERCP. We will discuss the specific risks for your procedure with you.

Sometimes it is not possible to complete the procedure. This may be because we cannot access the bile ducts or other structures. Sometimes a gallstone or stricture may make access difficult. If we are planning treatment, it may not always be possible to complete the treatment successfully.

These risks are the same for all procedures which involve ERCP, and not just when it is part of the EDGE procedure.

The main alternative to EDGE is a laparoscopic-supported ERCP. This procedure involves creating a connection between the skin and the part of the stomach which had been bypassed. An ERCP is then done using this connection.

The evidence we have indicates that EDGE is as safe and effective as laparoscopic-supported ERCP. Also EDGE does not involve any cuts (incisions) into the abdomen or any scarring as a result. Patients who have EDGE are also likely to spend less time in hospital after the procedure. However, it does require a second endoscopy procedure to remove the stent.

There is a procedure call percutaneous cholangioscopy which involves placing a drain into the liver through the wall of the abdomen. The drain is left in place for several weeks. After this a special type of endoscope is passed through the drain which can be used to access the bile ducts and perform an ERCP.

You will need to have a blood test before the procedure (usually within the previous two weeks). If this test is done at your local hospital or GP surgery it is important that you obtain a copy of the results and bring this with you. Since X-rays are taken during the procedure, please let us know in advance if there is any possibility you may be pregnant.

We will need to know about all the medications you take, in particular blood thinners, such as clopidogrel, warfarin, or apixaban, which may need to be stopped or reduced up to one week before the procedure.

It may be necessary to check with your cardiologist (or other specialist) to be sure that these can be discontinued prior to your procedure.

Please continue to take any other medication (including laxatives).

If you are a diabetic and take insulin, it is important that you continue taking your insulin but it is suggested that you reduce your dose on the day and night before the procedure. If you are concerned then contact your local diabetes nurse for advice. To keep you safe for the procedure, please check your blood sugars every three to four hours from the time you stop eating.

If you are taking tablets for your diabetes, please do not take them on the day of the procedure until after the procedure has been done.

Please bring your diabetic tablets or insulin to the hospital with you.

You should not eat anything for six hours before the appointment.

You may drink water only for up to four hours prior to the procedure (your usual prescription medicines can be taken with a sip of water).

It is likely you will be admitted to the ward overnight after the procedure so please bring an overnight bag. You may be given injections to thin the blood to prevent bloods clots while you are in hospital.

We want to involve you in all the decisions about your care and treatment. If you decide to go ahead with treatment, by law we must ask for your consent and will ask you to sign a consent form. This confirms that you agree to have the procedure and understand what it involves. The doctor will explain all the risks, benefits and alternatives before they ask you to sign a consent form. If you are unsure about any aspect of your proposed treatment, please do not hesitate to speak with a senior member of staff again.

Many patients have bloating and abdominal discomfort after the procedure. This usually settles after a few hours. Yourthroat may feel numb and sore. Most patients will need to wait four hours before trying to eat.

We will normally observe you for four hours in the Endoscopy Unit after the procedure. After this you will be transferred to the ward.

The evidence we have tells us that this is a safe procedure. However, the following symptoms might suggest a complication:

• severe persistent pain
• light-headedness, or fainting
• shivering or fever
• vomiting of blood
• passing of blood or black tar-like stools
• feeling generally very unwell.

If you have any problems please contact the Hepatobiliary Team Pathway Co-ordinator or Specialist Nurse in the first instance.

If you have a problem outside of office hours which cannot wait until the next day, please contact the hospital switchboard and ask to be put through to the on call Gastroenterology Registrar. In an emergency please visit your nearest Accident and Emergency Department. If possible take your discharge summary with you.

Contact information is provided below.

Hepatobiliary Pathway Co-ordinator (Monday to Friday 09:30-17:30)
Direct line: 020 3447 9229
Switchboard: 0845 155 5000 / 020 3456 7890 ext. 79229

Hepatobiliary Clinical Nurse Specialist (Monday to Friday 09:00-17:00)
Mobile: 07967 760146

Endoscopy Booking Team (Monday to Friday 09:00-17:00)
Direct line: 020 3456 7022
Switchboard: 08451 555 000 / 020 3456 7890 ext. 67022
E-mail: uclh.endoscopy@nhs.net

Endoscopy Recovery (Monday to Saturday 09:00-17:00)
Direct line: 020 3447 3282
Switchboard: 08451 555 000 / 020 3456 7890 ext. 73282

On-call Gastroenterology Registrar (out of hours emergencies only)
Switchboard: 08451 555 000 / 020 3456 7890

Address: Endoscopy Unit, University College Hospital, 2nd Floor Podium, 235 Euston Road, London, NW1 2BU