Impact of formal training in endoscopic submucosaldissection for early gastrointestinal cancer： A systematicreview and a meta-analysis

AIM To summarize the clinical impact of a formaltraining for the effectiveness and safety of endoscopicsubmucosal dissection for gastrointestinal cancer.METHODS： We searched databases including PubMed,EMBASE and the Cochrane Library and Science citationIndex updated to August 2014 to include eligible articles.In the Meta-analysis, the main outcome measurementswere en bloc resection rate, local recurrence rate （R0）and the incidence of procedure-related complications（perforation, bleeding）.RESULTS： En bloc resection was high for both,dissecting stomach tumors with an overall percentageof 93.2% （95%CI： 90.5-95.8） and dissecting colorectaltumors with an overall percentage of 89.4% （95%CI：85.1-93.7）. Although the number of studies reportingR0 resection （the dissected specimen was revealedfree of tumor in both vertical and lateral margins）was small, the overall estimates for R0 resection were81.4% （95%CI： 72-90.8） for stomach and 85.9%（95%CI： 77.5-95.5） for colorectal tumors, respectively.The analysis showed that the percentage of immediateperforation and bleeding were very low; 4.96 （95%CI：3.6-6.3） and 1.4% （95%CI： 0.8-1.9） for colorectaltumors and 3.1% （95%CI： 2.0-4.1） and 4.8% （95%CI：2.8-6.7） for stomach tumors, respectively.CONCLUSION： In order to obtain the same rate ofsuccess of the analyzed studies it is a necessity tocreate training centers in the western countries duringthe ＂several years＂ of gastroenterology residence firstonly to teach EGC diagnose and second only to trainendoscopic submucosal dissection.