Endoscopic Submucosal Dissection (ESD) Technique

Mechanisms of Improved Dissection Control

The European Society of Gastrointestinal Endoscopy (ESGE) recommends a stepwise approach for ESD in the colon, which reduces the risk of perforation and improves procedure control 1
A full circumferential incision isolating the lesion with a 3-4 mm margin of normal mucosa allows for better dissection control and increases the chances of en bloc resection 2
Additional submucosal injection after initial incision facilitates dissection by better lifting the tissue and increasing the visibility of the dissection plane 2
Dyes such as indigocarmine or methylene blue stain the submucosal fibers but not the muscularis propria, facilitating orientation in the safe submucosal plane 2

The stepwise method allows for precise dissection of the branched vascular network in the middle submucosal layer to reach the avascular layer just above the muscularis propria is not mentioned, however, controlled movements under direct vision, facilitated by the use of a cap, enable precise guidance of the ESD knife through the expanded submucosal layer 3

The stepwise approach reduces the risk of perforation, which is the most common complication of ESD (more frequent than in EMR) 1
The ability to better assess the depth of dissection and avoid damage to the muscularis propria is a key advantage of the stepwise approach 1
In the case of deep resection, the unstained muscularis propria will contrast with the blue-stained submucosa, helping to identify the dissection plane 2

ESD offers higher en bloc resection rates and more accurate pathological and oncological assessment compared to EMR 4
En bloc resection with ESD is safe and effective for rectal lesions, as the rectum is below the peritoneal reflection, making ESD in the rectum relatively less technically demanding and safer than in other colon regions 4
A large prospective study in North America showed that among 188 rectal lesions removed by ESD, 88.8% were removed en bloc, 85.6% achieved R0 resection, and 79.8% were considered curative 4
Hybrid ESD (partial submucosal dissection with subsequent en bloc resection using a snare) is a safer alternative to full ESD in the colon, especially when traction devices are not used 1