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Updated: Sep 3, 2026

The Pocket-Creation Procedure of Endoscopic Submucosal Dissection for Large Rectal Laterally Spreading Tumors
Published on: February 13, 2026
Learning curve of pocket-creation method-assisted colorectal endoscopic submucosal dissection: a single-operator
1Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea.
Background/Aims:
Colorectal endoscopic submucosal dissection (C-ESD) is a technically demanding procedure with an extended learning curve. We aimed to characterize the learning process after introduction of the pocket-creation method (PCM) and provide practical guidance for endoscopists.
Methods:
We retrospectively analyzed 147 colorectal lesions treated with PCM-assisted C-ESD. Learning curves for dissection speed and procedure time were evaluated using locally weighted regression. Cumulative sum (CUSUM) analysis was used to identify the point of technical stabilization, with a predefined acceptable failure rate of 10%. Outcomes were compared between the pre- and post-stabilization phases, and multivariate logistic regression was used to identify the predictors of technical failure.
Results:
Dissection speed increased and procedure time decreased with experience. CUSUM analysis identified stabilization at 60 cases. Compared with the post-stabilization phase, the pre-stabilization phase showed higher technical failure rates and lower en bloc and R0 resection rates. The learning phase was the only independent predictor of technical failure. Perforation occurred in 5.4% of cases and was managed predominantly endoscopically.
Conclusions:
PCM-assisted C-ESD showed a distinct learning curve, with stabilization achieved after 60 cases. Technical failure is primarily driven by operator experience rather than by lesion complexity.

