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 (R₀) 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 I² 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; I² = 0.00%] and R₀ resection rates [OR 1.16 (95% CI 0.36–3.76); P = 0.80; I² = 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; I² = 0.00%] and rates of recurrence [OR 0.46 (95% CI 0.07–3.14); P = 0.43; I² = 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.