Negative Effect of Prior Lesion Manipulation on Colorectal Endoscopic Submucosal Dissection Outcomes: A Retrospective Cohort Study.

Background: Endoscopic submucosal dissection (ESD) is a minimally invasive technique for en-bloc resection of superficial gastrointestinal lesions. However, the influence of prior manipulations, such as tattooing or endoscopic mucosal resection (EMR), on ESD outcomes is not well understood.

Methods: This retrospective cohort study evaluated 763 patients (mean age 64 years, 52% female) who underwent colorectal ESD at Brigham and Women's Hospital between 2014 and 2024. Outcomes included rates of en-bloc, R0, curative resection, and adverse events. Multivariable regression analysis identified factors associated with unsuccessful outcomes.

Results: The mean lesion diameter was 50 mm, with 54.4% located in the right colon. Prior tattooing occurred in 7% of cases while prior EMR was reported in 17% of lesions. En-bloc resection was achieved in 95% of cases, R0 resection in 89%, and curative resection in 88%. The mean procedure time was 64 min, with adverse events including delayed bleeding (3.3%), muscle injury (0.9%), and perforation (0.8%). Factors linked to unsuccessful en-bloc resection were prior tattooing (OR 0.30, 95% CI 0.09-0.98; P = 0.047), prior EMR (OR 0.31, 95% CI 0.12-0.82; P = 0.017), and submucosal fibrosis (OR 0.20, 95% CI 0.07-0.53; P = 0.001). Submucosal fibrosis also reduced R0 and curative resection rates. No statistically significant associations between procedural adverse events and fibrosis, prior EMR, or tattooing were found.

Conclusions: These findings highlight the importance of avoiding unnecessary pre-procedural manipulations and emphasize the need for urgent planning to optimize ESD outcomes.