Comparison of surgical quality and long-term outcome between hybrid trans-anal total meso-rectal excision and laparoscopic total meso-rectal excision: a systematic review and meta-analysis

BACKGROUNDLaparoscopy-assisted trans-anal TME (ta-TME), or hybrid ta-TME, inherited the advantages of both trans-anal surgery and trans-abdominal surgery, and is gaining increasing acceptance from colorectal surgeons worldwide. This research aims to make a comprehensive comparison between hybrid ta-TME surgery and traditional laparoscopic TME (la-TME) surgery regarding surgical quality and long-term survival. METHODSCochrane Library, EMbase, Web of Science and PubMed were searched for studies comparing hybrid ta-TME with traditional la-TME. Indicators for surgical quality and long-term prognosis were extracted and pooled. Heterogeneity was assessed with I2 index and was significant when p < 0.1 and I2 > 50%. Publication bias was estimated by Eggers test, where p<0.1 was considered statistically significant. RESULTS13 studies with 992 patients were included in meta-analysis, of which 467 were in hybrid ta-TME cohorts, and 525 were in traditional la-TME cohorts. Compared with traditional la-TME, hybrid ta-TME has lower rate of positive circumferential margin (RR=0.454, 95%CI 0.240~0.862, p=0.016) and lower conversion rate (RR=0.336, 95%CI 0.134~0.844, p=0.020). On rate of positive distal resection margin, completeness/near-completeness of meso-rectum, overall complications, anal leakage, ileus, urinary dysfunction, 2-year DFS and 2-year OS, there were no significant difference between the two techniques. CONCLUSIONSHybrid ta-TME is significantly superior to traditional la-TME in ensuring CRM safety and lowering intra-operative conversion rate, and is meanwhile not inferior on other major outcome indicators concerning surgical quality and long-term survival. To further understand this new surgical technique, we need high-quality RCTs, as well as previous researchers updates with results of prolonged follow-up.