Endoscopic Submucosal Dissection (ESD)

Endoscopic Submucosal Dissection (ESD) is a highly specialised, minimally invasive endoscopic technique designed to remove early cancers or precancerous growths in the gastrointestinal (GI) tract in a single, intact piece (en bloc). Unlike the simpler technique of Endoscopic Mucosal Resection (EMR), ESD allows for deeper, more complete removal of lesions, including those that extend into the submucosal layer, without the need for traditional open or laparoscopic surgery. The procedure uses a flexible endoscope fitted with specialised micro-knives, injection tools, and high-definition imaging, enabling the gastroenterologist to precisely dissect beneath the lesion and extract it with clear margins.

ESD is indicated when:

• A lesion (polyp, tumour) has been identified in the esophagus, stomach, small intestine, colon, or rectum that is suspected to be early-stage, confined to mucosa/submucosa, and has not invaded deeper muscle or spread to lymph nodes.
• Lesions are too large or flat to be safely removed by standard EMR, yet surgery is not the preferred initial option.
• Organ-preserving treatment is desired (e.g., preserving the stomach, colon, and esophagus) rather than removing part of the organ via surgery.

By detecting and treating such lesions early through ESD, the risk of progression to advanced cancer can be significantly reduced while keeping the patient’s digestive tract intact.

• Preparation: Patients will be asked to fast (for upper GI lesions) or perform bowel preparation for lower GI lesions. Sedation (often general anaesthesia or deep monitored sedation) is used.
• Marking & Injection: The lesion is identified with an endoscope. A fluid (often saline/hyaluronic acid) is injected underneath the lesion to lift it from the muscle layer, creating a safe cushion.
• Incision & Dissection: A circumferential incision is made around the lesion, then the submucosal layer is carefully dissected using specialised knives. The goal is to remove the entire lesion in one piece (en bloc) with intact margins.
• Haemostasis & Retrieval: Any bleeding vessels are coagulated, and the removed specimen is retrieved for pathology. The site is checked for completeness of resection and any perforation risk.
• Recovery: After the procedure, patients are observed. Many return home the same day or after a short hospital stay, depending on lesion site and complexity.

• Complete removal (curative intent): Because the lesion is removed intact, pathologists can assess margins and depth precisely, which helps determine if further treatment is needed.
• Organ‐preserving: Unlike open surgery, ESD keeps the organ (e.g., stomach, colon) intact, preserving its function and quality of life.
• Minimal external trauma: No major incisions, fewer postoperative complications, faster recovery, and shorter hospital stay compared to surgery.
• Lower recurrence risk: With correct execution, en bloc removal reduces the chance of lesion recurrence compared to piecemeal removal.

Although ESD is safe when performed by experienced endoscopists in an appropriate setting, there are potential risks:

• Bleeding: Occurring during or after the procedure; usually managed endoscopically.
• Perforation: Since dissection is close to the bowel muscle layer, there is a small risk of creating a hole in the wall, which may require further endoscopic closure or surgery.
• Stricture formation: Especially in esophageal applications, removal of large portions may lead to narrowing requiring dilation.
• Operator-dependent outcome: The success and safety of ESD depend heavily on the skill of the endoscopist and the equipment used.