Learning Curve Associated With Colorectal Endoscopic Submucosal Dissection for Endoscopists Experienced in Gastric Endoscopic Submucosal Dissection

Abstract

Colorectal endoscopic submucosal dissection requires a high level of skill and experience in therapeutic endoscopy because of the high risk of complications such as perforation and bleeding. Greater understanding of the procedural learning curve is required to standardize training and to achieve wider acceptance of this procedure. The aims of this study were to evaluate the clinical outcomes of colorectal endoscopic submucosal dissection and to clarify its learning curve for endoscopists. We retrospectively reviewed the clinical outcomes for consecutive patients with colorectal neoplasms who underwent endoscopic submucosal dissection by 2 trainees under the guidance of experienced specialists. The study was performed at the National Cancer Center Hospital, Tokyo, Japan. Colorectal endoscopic submucosal dissections were performed for 101 consecutive patients with 102 colorectal neoplasms between April 2008 and December 2010. Procedure time, en bloc resection rate, completion rate, and complications were retrospectively compared between 4 training periods in which each trainee performed 10 endoscopic submucosal dissections per period and a final training period in which the trainees performed 10 to 12 endoscopic submucosal dissections to analyze the skill improvement with time. The procedure time and en bloc resection rate were not significantly different among the training periods. However, the completion rates in the fourth (100%) and fifth (95.5%) training periods (≥ 31 cases/trainee) were significantly higher (P < .001) than those in the first (45%), second (70%), and third (80%) training periods (1-30 cases/trainee). Two cases of perforation occurred during the study. Limitations include the single-center design. Training programs and instruments vary with institution, which could affect the learning curve. Trainee endoscopists are able to perform colorectal endoscopic submucosal dissection without serious complications under the guidance of experienced specialists. They can perform it safely and independently after preparatory training and experience with ≥ 30 cases.