The Efficacy And Safety Of Transanal Total Mesorectal Excision For Patients With Middle And Low Rectal Cancer

Purpose: Rectal cancer is one of the most common cancers in the world,and surgery is still the main method of treating rectal cancer.However,there are many limitations in the resection of middle and low rectal cancer,and a new type of surgical procedure,namely transanal total mesenteric resection(TaTME),has emerged.However,whether TaTME is superior to laparoscopic total rectal resection(LaTME)in the treatment of middle and low rectal cancer remains controversial.Therefore,this study will use the methods of evidence-based medicine-meta-analysis to compare the efficacy of TaTME and LaTME in patients with middle and low rectal cancer for clinical reference.Methods: We searched the following databases: The Cochrane Library,PubMed,Embase,Web of Science,VIP,WanFang,China National Knowledge Infrastructure(CNKI)and China Biology Medicine(CBM)Database,and collected all the relevant studies which compared the efficacy of TaTME and LaTME in patients with middle and low rectal cancer.Two researchers who were trained in evidence-based medicine institutions independently conducted literature screening,data extraction,and quality evaluation of the included literature.Meta-analysis was conducted by Review Manager 5.3 software.We used odds ratios(OR)and 95% confidence interval(CI)to evaluate dichotomous variables.Continuous variables were analyzed by weighted mean difference(WMD)with a 95% CI.Results: In terms of safety,in matched case controls(MCCs)and randomized controlled trials(RCTs),the results of meta-analysis showed that TaTME has a shorter operative time than LaTME,and the difference is statistically significant [WMD =-33.19,95%CI =-43.78 ~-22.61,P < 0.05;WMD =-25.43,95%CI =-38.95~-11.92,P < 0.05].In the MCCs,the results of meta-analysis demonstrated that,compared with LaTME,TaTME had the advantages of shorter hospital stay,lower conversion and readmission rate,and the differences were all statistically significant [WMD =-1.65,95%CI =-3.10 ~-0.20,P < 0.05;OR = 0.19,95%CI = 0.07~ 0.57,P < 0.05;OR = 0.43,95%CI = 0.21~ 0.84,P < 0.05].But 2 outcome indicators in front were not statistically different in RCTs [WMD =-1.00,95%CI =-14.35 ~12.35,P > 0.05;OR = 0.45,95 % CI = 0.13 ~ 1.56,P > 0.05].In the MCCs study,the meta-analysis showed that TaTME had similar intraoperative complications,lowerpostoperative complications,and blood loss compared with LaTME,but the differences were not statistically significant [OR = 0.94,95%CI = 0.30 ~ 3.01,P > 0.05;OR = 0.79,95%CI =0.52~ 1.21,P > 0.05;WMD =-26.86,95%CI =-56.64~ 2.91,P > 0.05].In terms of efficacy,in MCCs,the result of quantitative synthesis showed that TaTME had a higher risk of positive distal margin and a better distal margin than LaTME,but there was no statistical difference[WMD = 3.37,95%CI =-2.67~ 9.42,P < 0.05;OR = 2.54,95%CI = 0.43 ~ 15.16,P > 0.05].In MCCs,meta-analysis illustrated that TaTME had a better circumferential margin and a lower positive circumferential margin than LaTME,and the difference is statistically significant[WMD = 0.82,95%CI = 0.56~ 1.28,P < 0.05;WMD = 0.43,95%CI = 0.22~ 0.84,P < 0.05].But in RCTs,the results displaied no statistical difference [WMD = 1.67,95%CI =0.04 ~ 3.38,P > 0.05].Conclusions: TaTME had better efficacy than LaTME for the patients with mid or low rectal cancer,effectively reducing the incidence of positive peripheral margin.But in terms of safety,there was no significant difference and its authenticity remains more high-quality researches to verify.