Endoscopic Submucosal Dissection vs Endoscopic Mucosal Resection for Rectal Carcinoid Tumor. A Meta-Analysis and Meta Regression with Single Arm Analysis.

Introduction Endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) are two common procedures used for resection of rectal carcinoid tumors. As there is currently no consensus regarding the optimal endoscopic resection techniques, a meta-analysis was conducted to compare efficacy and safety of ESD and EMR for the treatment of rectal carcinoid tumors. Methods Medline and Embase were sieved up to October 2020. Outcomes examined included en bloc resection, complete resection, bleeding, margin involvement, resection time, requirement for additional surgery, perforation, and recurrence rate. Risk ratios and weighted mean differences were used for Dersimonian and Laird random-effects in pairwise meta-analysis. Single-arm meta-analysis of proportions and random-effects meta-regression analysis were also conducted. Results 22 studies involving 1,360 rectal carcinoid tumors were included. 655 rectal carcinoids underwent ESD whereas 705 rectal carcinoids underwent EMR. ESD had comparable resection quality to EMR for tumours smaller than 10mm. However, analysis of tumours smaller than 20mm showed significantly higher rates of complete resection, vertical margin, and bleeding in ESD than EMR. The mean operation time for ESD was also longer and required less additional surgery relative to that of EMR. Conclusion This study indicates that ESD is more effective in providing curative treatment for rectal carcinoid tumors larger than 10mm as ESD can achieve higher complete resection rate with lower vertical margin involvement than EMR. In contrast, both ESD and EMR are suitable treatment options for rectal carcinoid tumors smaller than 10mm since both techniques provide similar efficacy.