Underwater EMR

Underwater Mucosectomy (UM) is an advanced endoscopic technique used to remove mucosal lesions in the colon or rectum without the need for submucosal injection. It is a variation of Endoscopic Mucosal Resection (EMR) and is performed under water immersion to facilitate safer and more effective resection.

This is a demonstration of 20 mm flat lesion, LST in the lower rectum Nice 2 Conecct 2A, we used a 15 mm snare with help of the immersion we could catch all the polyp a get a onblock resection.

Key Features of Underwater Mucosectomy:

No Submucosal Injection Required – Unlike traditional EMR,

UM uses water to create a cushion, eliminating the need for fluid injection.

Underwater Environment – The colon is filled with water, which helps lift the mucosa away from the muscle layer, reducing the risk of perforation.

Improved Visualization – Water immersion clears blood and debris, enhancing visibility during the procedure.

Safer for Larger or Flat Lesions – Particularly useful for lesions >10 mm or laterally spreading tumors (LSTs).

Advantages Over Traditional EMR:

Faster – No time spent on submucosal injection.

Lower Cost – Avoids expensive injection solutions.

Reduced Risk of Bleeding/Perforation – Water provides a natural cushion.

Better R0 Resection Rates – Higher chance of complete removal.

Indications:

1/ Colorectal polyps (especially flat or sessile lesions 10–20 mm).

2/ Laterally spreading tumors (LSTs).

3/ Benign or early malignant lesions (T1a).