Endoscopic submucosal dissection for large superficial colorectal tumors using the “clip-flap method”

Endoscopic submucosal dissection (ESD) is technically difficult because of poor visualization and instability in the cutting area. Although mucosal flap formation improves visualization of the cutting area, it is difficult to achieve, especially in colorectal ESD. To facilitate mucosal flap formation, we developed the "clip-flap method" by substituting an endoclip for the mucosal flap until it is formed.The clip-flap method was applied to 114 of 119 large superficial colorectal tumors being treated by ESD. Therapeutic efficacy and safety were assessed.Mean tumor diameter, resected specimen diameter, and procedure time were 32.5 mm, 38.9 mm, and 82.0 minutes, respectively. The en bloc resection rate was 97.5 %. Intraoperative perforation occurred in one patient who was treated conservatively. A single endoclip was used for 92 lesions and improved visualization of the cutting area. A cross pattern of endoclips was used for 22 lesions and further stabilized the visual field, especially near the lateral side.The clip-flap method is a simple, safe, and effective option for ESD of large superficial colorectal tumors.