Endoscopic submucosal dissection (ESD) versus transanal endoscopic microsurgery (TEM) for treatment of rectal tumors: a comparative systematic review and meta-analysis

Background While multiple studies have evaluated endoscopic submucosal dissection (ESD) and transanal endoscopic microsurgery (TEM) to remove large rectal tumors, there remains a paucity of data to evaluate their comparative efficacy and safety. The primary aim of this study was to perform a structured systematic review and meta-analysis to compare efficacy and safety of ESD versus TEM for the treatment of rectal tumors. Methods Individualized search strategies were developed from inception through November 2018 in accordance with PRISMA guidelines. Measured outcomes included pooled enbloc resection rates, margin-negative (R-0) resection rates, procedure-associated adverse events, and rates of recurrence. This was a cumulative meta-analysis performed by calculating pooled proportions. Heterogeneity was assessed with Cochran Q test and I-2 statistics, and publication bias by funnel plot using Egger and Begg tests. Results Three studies (n = 158 patients; 55.22% male) were included in this meta-analysis. Patients with ESD compared to TEM had similar age (P = 0.090), rectal tumor size (P = 0.108), and diagnosis rate of adenoma to cancer (P = 0.53). ESD lesions were more proximal as compared to TEM (8.41 +/- 3.49 vs. 5.11 +/- 1.43 cm from the anal verge; P < 0.001). Procedure time and hospital stay were shorter for ESD compared to TEM [(79.78 +/- 24.45 vs. 116.61 +/- 19.35 min; P < 0.001) and (3.99 +/- 0.32 vs. 5.83 +/- 0.94 days; P < 0.001), respectively]. No significant differences between enbloc resection rates [OR 0.98 (95% CI 0.22-4.33); P = 0.98; I-2 = 0.00%] and R-0 resection rates [OR 1.16 (95% CI 0.36-3.76); P = 0.80; I-2 = 0.00%] were noted between ESD and TEM. ESD and TEM reported similar rates of adverse events [OR 1.15 (95% CI 0.47-2.77); P = 0.80; I-2 = 0.00%] and rates of recurrence [OR 0.46 (95% CI 0.07-3.14); P = 0.43; I-2 = 0.00%]. Conclusion ESD and TEM possess similar rates of resection, adverse events, and recurrence for patients with large rectal tumors; however, ESD is associated with significantly shorter procedure times and duration of hospitalization. Future studies are needed to evaluate healthcare utilization for these two strategies.