Endoscopic Submucosal Dissection (ESD)

Endoscopic submucosal dissection is the removal, with an endoscope and without an operation, of early cancers and pre-cancerous lesions of the digestive system.

Its purpose is to take out in one piece and with clear margins a tumour that is still confined to the superficial layers of the wall — the mucosa and the submucosa. The organ itself stays; no stomach or bowel is removed.

How ESD differs from EMR

In EMR, fluid is injected under the lesion and the lesion is then caught in a wire snare and cut. That is quick and effective for small lesions, but a large lesion will not fit in the snare and has to be taken piece by piece.

In ESD the edge of the lesion is marked, fluid is injected underneath, and the lesion is cut free step by step from below the lining with special endoscopic knives. It is a longer and harder procedure, but it allows removal in one piece whatever the size of the lesion.

Why that matters: only on a single specimen can the pathologist say reliably whether the cut margins are clear. Removal in one piece also lowers the rate of recurrence.

When is it preferred?

• Early cancers of the gullet, the stomach and the large bowel
• Lesions larger than 2 centimetres, flat or broad-based
• Barrett’s oesophagus in which dysplasia has developed
• Lesions that could not be taken in one piece by EMR

ESD is not appropriate where the lesion has gone into the deeper layers or where spread to the lymph nodes is suspected; those patients need surgery.

How do you prepare?

Because it takes a long time and the patient has to stay still, it is generally done under general anaesthesia or deep sedation. Nothing is eaten beforehand, and a blood count and clotting tests are asked for.

Blood-thinning drugs need to be stopped a few days in advance, unless there is a medical reason against it.

Consent form

The clinic’s consent form will be signed.

Afterwards

A stay of one or several days in hospital generally follows ESD. Nothing is given by mouth on the first day; then liquids are started and normal eating is resumed by degrees. Drugs that suppress stomach acid are taken for a time.

What are the risks?

• Bleeding — during or after the procedure; mostly stopped endoscopically
• Perforation — more frequent than with EMR; usually closed with a clip in the same session
• Narrowing as a wide resection heals

The pathologist’s examination of what was removed is what decides matters: if the margins are clear and the tumour superficial, the treatment counts as complete; if not, surgery or further treatment comes into question.