Abstract:Objective To evaluate the safety and effectiveness of endoscopic mucosal resection with circumferential incision (EMR-CI) and endoscopic submucosal dissection (ESD) for the rectal neuroendocrine neoplasm (RNEN).Methods Databases such as PubMed, the Cochrane Library, Embase, Web of Science, SinoMed, China National Knowledge Infrastructure (CNKI), Wanfang Data and Weipu database were searched by computer. The retrieval time limit was Nov. 22, 2022. The Chinese and English literatures on the efficacy of EMR-CI vs ESD in treatment of RNEN patients were collected. According to inclusion and exclusion criteria, the included literatures were screened , extracted data, and evaluated the methodological quality by Newcastle-Ottawa scale (NOS), Meta-analysis was performed using Rev Man 5.3 software.Results Seven clinical control studies were included, including 199 cases in the EMR-CI group and 443 cases in the ESD group. Results of Meta-analysis of validity outcome indicators, there was no significant difference in histological complete resection rate between the EMR-CI group and the ESD group (OR^ = 0.56, 95%CI: 0.30~1.02, P = 0.060); The endosopic complete resection rate of EMR-CI was similar to that of ESD with no significant difference (OR^ = 0.33, 95%CI: 0.09~1.17, P = 0.090); The size of lesions removed by EMR-CI was smaller than that of ESD with significant difference (WMD = -0.86, 95%CI: -1.33~-0.40, P = 0.000); The time EMR-CI required to remove the lesion was significantly shorter than that of ESD (WMD = -12.48, 95%CI: -16.42~-8.54, P = 0.000). The positive rate of horizontal resection margin of EMR-CI was similar to that of ESD, with no significant difference (OR^ = 1.74, 95%CI: 0.64~4.75, P = 0.280); The positive rate of vertical resection margin was significantly higher than that of ESD (OR^ = 2.41, 95%CI: 1.09~5.32, P = 0.030). Due to the low local recurrence rate and distant metastasis rate, Meta-analysis couldn't be compared. Safety outcome index showed that, there were no significant differences in the incidence of total complications, bleeding and perforation among groups.Conclusion In the treatment of RNEN, EMR-CI can achieve the endosopic complete resection, histological complete resection and positive rate of horizontal resection margin similar to ESD without increasing surgical complications and significantly saving surgical time. However, attention should be paid to the differences between EMR-CI and ESD in positive rate of vertical resection margin.