Transanal Endoscopic Microsurgery Versus Standard Transanal Excision for the Removal of Rectal Neoplasms: A Systematic Review and Meta-analysis

BACKGROUND: Transanal endoscopic microsurgery is the intraluminal excision of rectal lesions with the use of instrumentation to maintain a stable pneumorectum, enabling a magnified view of the target lesion. Despite suggested benefits over traditional transanal excision, there is no consensus on which technique is superior. OBJECTIVE: The aim of the current study is to use meta-analytical techniques to compare transanal endoscopic microsurgery with transanal excision. DATA SOURCES: A comprehensive literature search of PubMed, Embase, and The Cochrane Library was performed. STUDY SELECTION: All studies comparing transanal endoscopic microsurgery with transanal excision were included. INTERVENTIONS: Transanal endoscopic microsurgery was compared with transanal excision by using random-effects methods to combine data. Data are presented as ORs with 95% CIs. MAIN OUTCOME MEASURES: The main outcomes measured were postoperative complication rate, negative microscopic margin rate, specimen fragmentation rate, and lesion recurrence. RESULTS: Six comparative series comparing outcomes following 927 local excisions were identified. There was no difference between techniques in postoperative complication rate (OR, 1.018; 95% CI, 0.658-1.575; p = 0.937). Transanal endoscopic microsurgery had a higher rate of negative microscopic margins in comparison with transanal excision (OR, 5.281; 95% CI, 3.201-8.712; p < 0.001). Transanal endoscopic microsurgery had a reduced rate of specimen fragmentation (OR, 0.096; 95% CI, 0.044-0.209; p < 0.001) and lesion recurrence (OR, 0.248; 95% CI, 0.154-0.401; p < 0.001) compared with transanal excision. There was no across-study heterogeneity for any end point. LIMITATIONS: Most studies were retrospectively designed, and there were variations in patient populations and duration of follow-up. CONCLUSIONS: Available data are limited because of a lack of randomized controlled trials. However, based on current evidence, transanal endoscopic microsurgery is oncologically superior to transanal excision for the excision of rectal neoplasms.