ESD of a lesion in the anterior and lesser curvature of the antrum

What endoscopic submucosal dissection is

ESD allows a lesion of the digestive tract to be removed in a single piece, through the endoscope and without any external incision. Fluid is injected beneath the lesion to lift it away from the muscle layer, the margins are marked, and the submucosa is then dissected under direct vision.

Why en bloc resection matters

This is the essential difference from mucosal resection (EMR), which removes tissue in fragments. Only en bloc removal allows the pathologist to assess the resection margins and the depth of invasion with confidence. That determines whether the removal was oncologically adequate, and it lowers the risk of local recurrence.

Intestinal metaplasia and dysplasia

Chronic gastritis leads to atrophy and intestinal metaplasia. Once dysplasia is added, the lesion sits within the sequence that ends in gastric cancer.

The role of chromoendoscopy

Before resection, chromoendoscopy with magnification defines the true margins of the lesion, which frequently extend beyond what is visible in white light. Without this step, resection risks leaving residual tissue behind.

After the resection

The specimen is sent for histology, and it is that report rather than the endoscopic appearance that determines the next step. Surveillance intervals are set by guideline and individualised per case; they are set out in detail on the page for colonoscopy.