Factors Affecting Complete Resection And Technical Diiffculty In Endoscopic Submucosal Dissection For Colorectal Tumors

Background:Though the development of the endoscopy promote the applicationof ESD in clinic, colorectal ESD is more technically difficult than gastricESD due to the anatomy of the large intestine, with its narrow lumen, thinwalls, and redundancy. Also, a number of factors, including the presenceof fibrosis and large-sized lesions, location in the colon, and endoscopistshaving relatively little experience can cause the difficulty of ESD, andcause an increase in the number of incomplete resections.Research purposes:To summarize the clinicopathlogical characteristics of patients whoaccepted the colorectal ESD treatment. To probe factors leading toincrease of the technical difficulty and decrease of the complete resectionin endoscopic submucosal dissection for colorectal tumors for aiming toprovide the reference and guide the dicision for clinical work. Materials and Methods:This retrospective study included95consecutive colorectal tumorswhose pathological diagnosis was adenoma and carcinoma treated byESD in88patients at the Department of Endoscopy of the FirstHospital of Jilin University from January2013to December2014. Weevaluated the clinical outcomes of all cases and conducted multiplelogistic regression analysis of the following factors related to incompleteresection and difficult procedure: age（＜75or≥75）, gender, location(right colon, left colon or rectum), tumor size (diameter＜40or≥40mm),pahtological diagnosis(low-grade adenoma or high-grade adenoma andcarcinoma), operation time, morphology [granular-type laterallyspreading tumor (LST-G), non-granular-type laterally spreading tumor(LST-NG), or protruded type] and fibrosis(no fibrosis, mild fibrosis orsevere fibrosis) Resection was devided as complete resection(when thetumor was removed en bloc with lateral and basal margins tumor-free)and incomplete resection. A procedure that required more than120minwas defined as a difficult colorectal ESD.Results:Average tumor size was28.7±14.1（range,8-80）mm, and the averageprocedure length was80.72±63.90min. The rate of complete resectionwas92.6%（88/95）, and the rate of incomplete resection was7.4%(7/95),Multivariate logistic regression analysis revealed that fibrosis (P=0.012， OR=52.473) contributed to incomplete resection and that the tumor size(P＜0.05), fibrosis (P＜0.05) and the shape of lesions (P＜0.05) wereindependent factors exacerbating the difficulty of colorectal ESD.Conclusion:Severe fibrosis was the independent factors to incomplete resection.The severer fibrosis can induce higher rate to the incomplete resection.Fibrosis, the size of tumors and the shape of tumors were independentfactors exacerbating the difficulty of colorectal ESD. The severer fibrosisand bigger size can exacerbate difficulty of colorectal ESD. LST-G tumorand LST-NG tumor are more likely to exacerbate the difficulty ofcolorectal ESD than protruded type.