Analysis of Predictive Factors for R0 Resection, Bleeding and Recurrence of Colorectal Adenomas after Endoscopic Mucosal Resection

Abstract

Background:
Larger colonic polyps require advanced resection techniques such as endoscopic mucosal resection (EMR) for safe and effective removal. There is a steady accumulation of scientific evidence with regard the technical aspects and long-term outcomes of colonic EMR compared with surgery.

Objective:
This study aimed to identify and analyze different factors predictive of clinical outcomes for patients undergoing EMR of colorectal lesions.

Methods:
This is a retrospective cohort study on all patients who underwent colorectal EMR from January 2015 to December 2018. The diagnostic yield of Japan NBI Expert Team (JNET) classification and clinical outcomes, namely, R0 resection, complications and recurrence of lesions, were studied.

Results:
Two hundred eighty-two patients were studied. The R0 resection rate was 96.3% (n=231) for lesions resected en bloc; 15.2% (n=43) presented with a complication, most commonly presenting as intra-procedural bleeding (n=36, 12.8%); and 10.7% (n=11) had recurrence post-EMR on surveillance colonoscopy. Main predictors of recurrence include a non-granular morphology of a resected polyp (cOR 2.621 [95% CI 1.0-6.84]) and piecemeal resection (cOR 2.306 [95% CI 1.06-5.04]). A larger lesion size of >20 mm was associated with both positive resection margin and post-EMR complications. The JNET classification exhibited good sensitivity for Type 1 (71.8%) and Type 2A (91.9%) and good specificity for Type 1 (96.9%) and Type 2B (95.5%). Accuracy was high for JNET Types 1 (91.02%), 2A (80.24%), and 2B (89.22%).

Conclusions:
EMR is an important advancement in the field of therapeutic endoscopy with good clinical outcomes. The JNET classification has a high diagnostic accuracy rate; hence is a good endoscopic tool for characterization of lesions.