[Meta-analysis of extralevator abdominoperineal excision for rectal cancer]

To evaluate the efficacy of extralevator abdominoperineal excision (ELAPE) of rectal cancer.

PubMed, Cochrane Library and Embase database were searched for clinical studies comparing the ELAPE and abdominoperineal excision (APE) for rectal cancer between 2007 and 2016. Two reviewers independently screened the articles and extracted the data. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the observational studies and the score more than 5 points was the inclusion criteria. Cochrane Handbook for Systematic Reviews of Interventions v5.1.0 was used to evaluate the quality of the randomized controlled trials (RCT). Intra-operative perforation rate, circumferential resection margin (CRM) involvement, local recurrence rate, perineal wound complications were brought into meta-analysis by Review Manager 5.3 software.

A total of 556 articles were retrieved and 12 articles were enrolled finally, including 11 observational studies and 1 RCT study. All the 12 articles were high quality (scores of all observational studies were more than 11 points, RCT study accorded with 6 criteria of the quality evaluation). A total of 3 788 patients were enrolled, including 2 141 cases of ELAPE and 1 647 cases of APE. Meta-analysis revealed that intra-operative perforation rate of ELAPE was lower than APE (RR=0.52, 95%CI:0.34-0.79, P=0.002). There were no significant differences between two groups in CRM involvement (RR=0.72, 95%CI:0.49-1.07, P=0.10), local recurrence rate (OR=0.55, 95%CI:0.24-1.29, P=0.17) and perineal wound complications (RR=0.94, 95%CI:0.58-1.53, P=0.800).

Compared with APE, ELAPE reduces the intra-operative perforation rate, and does not increase the perineal wound complications, but it has no advantages in decreasing the CRM involvement and local recurrence rate.