Risk Factors for Technical Difficulty of Endoscopic Submucosal Dissection in Colorectal Tumors: A Case Series and Meta-Analysis

Abstract Background and Aims: Endoscopic submucosal dissection has become widely accepted as an efficient and well-established option for colorectal neoplastic lesions (CRNs). However, there are still some barriers for endoscopists that hinder the successful ESD. The current study was to evaluate risk factors for the failure of en-bloc resection in the colorectal endoscopic submucosal dissection (ESD).Methods: A retrospective chart review was performed from patients who underwent ESD for colorectal neoplasms (CRNs) between January 2015 and April 2017. The demographics and colonoscopic reports were analyzed. A meta-analysis was conducted for the risk factors for the failure of en-bloc or R0 resection. Results: 253 ESD cases were completed in en-bloc resection. Ulcerative colitis, previous abdominal surgeries, lesions on the Bauhin’s valve/ dentate line, non-lifting sign and submucosal fibrosis were associated with the failure of en-bloc resection (P<0.05). Meta-analysis showed that laterally spreading tumors, tumor larger than 40mm, Bauhin’s valve/dentate line, flexure, non-lifting sign, and submucosal fibrosis were the factors for the failure of en bloc or R0 resection. The rates of perforation were obviously higher in N-EBR groups compared to EBR groups. No significant results can be observed on the local recurrence based on these studies. Conclusions: Preoperative factors such as laterally spreading tumors, tumor larger than 40mm, Bauhin’s valve/dentate line, flexure and intraoperative factors such as non-lifting sign, submucosal fibrosis should be put more focus to reach better outcomes in CRNs patients.