Endoscopic Mucosal Resection (EMR)

Endoscopic mucosal resection is the removal, with an endoscope and without an operation, of polyps and early lesions that are confined to the surface layer of the digestive tract.

It differs from an ordinary polypectomy in this: a polyp on a stalk can be cut straight away with a snare, but a flat or broad-based lesion has to be lifted first before a snare can catch it.

Consent form

The clinic’s consent form will be signed.

How is it done?

Saline is injected underneath the lesion. The fluid separates the lesion from the muscle layer beneath and lifts it like a cushion. That both brings the lesion within reach of the snare and reduces the risk of damaging the muscle layer and perforating it as the cut is made.

The lifted lesion is encircled with a wire snare and cut away with an electrical current. What is removed is sent to the pathology laboratory.

If the injected fluid does not lift the lesion — if there is no lifting sign — that suggests the lesion may have gone deeper, and endoscopic removal is generally not appropriate.

When is it preferred?

EMR is generally preferred for lesions under 2 centimetres with a low suspicion of cancer. Lesions larger than that can be removed piece by piece, but piecemeal removal makes assessment by the pathologist harder and carries a higher rate of recurrence.

For larger, flat or higher-risk lesions, endoscopic submucosal dissection (ESD) is preferred because it allows removal in one piece.

How do you prepare?

Six to eight hours without food for the upper digestive tract; full bowel cleansing, as for a colonoscopy, for the large bowel.

Blood-thinning drugs need to be stopped a few days beforehand, unless there is a medical reason against it — they raise the risk of bleeding after the cut.

Afterwards

Eat lightly and softly that day. Abdominal pain, fever or bleeding from the back passage should be reported to the doctor.

What are the risks?

• Bleeding — the commonest complication; it can happen during the procedure or a few days later, and is usually stopped endoscopically
• Perforation — uncommon, and can be closed with a clip
• The lesion not being removed completely, and recurrence

Depending on what the pathologist reports on the piece removed, further treatment or endoscopic follow-up at set intervals may be needed.