Factors affecting the technical difficulty and clinical outcome of endoscopic submucosal dissection for colorectal tumors

Abstract

Endoscopic submucosal dissection (ESD) for colorectal tumors is technically difficult due to the anatomy of the large intestine, with its narrow lumen, thin walls, and redundancy. Here, we assessed factors associated with incomplete resection and difficult colorectal ESD. Between November 2009 and April 2013, we performed ESD on 151 consecutive colorectal tumors in 147 patients. We evaluated the clinical outcomes of all cases and conducted multiple logistic regression analysis of the following factors related to incomplete resection and difficult procedure: age, gender, location (right colon, left colon or rectum), tumor size (diameter ≥40 or <40 mm), operation time, morphology [granular-type laterally spreading tumor (LST-G), non-granular-type laterally spreading tumor (LST-NG), or protruded type], fibrosis, and paradoxical movement during the procedure. A procedure that required more than 120 min was defined as a difficult colorectal ESD. Average tumor size was 32.1 ± 10.7 mm, and the average procedure length was 71.8 ± 49.5 min. The rate of en bloc resection was 94.7%, while that of en bloc curative resection was 86.8%. Perforation occurred in 1.3% of the ESD procedures. Multivariate logistic regression analysis revealed that only severe fibrosis [odds ratio (OR) 4.51; 95% confidence interval (CI) 1.36-14.91, p = 0.014] contributed to incomplete resection and that a tumor size exceeding 40 mm (OR 5.73 [95% CI 1.66-19.74], p = 0.006), severe fibrosis (OR 23.31 [95% CI 6.59-82.54], p < 0.001), and paradoxical movement (OR 4.26 [95% CI 1.11-16.44], p = 0.035) were independent factors exacerbating the difficulty of colorectal ESD. Severe fibrosis contributed to both incomplete resection and difficult colorectal ESD. Larger tumor size and paradoxical movement during the procedure were independent factors contributing to the difficulty of colorectal ESD. These factors might enable endoscopists to develop strategies for treating colorectal ESD.