A comparison of open, laparoscopic and robotic TME: trial sequential analysis and network meta-analysis.

Aim Total mesorectal excision (TME) for rectal cancer can be achieved by employing open (OpTME), laparoscopic (LaTME) and robotic (RoTME) approaches but which of these has the best outcome? The aim of present study is to identify the most effective technique for rectal cancer by comparing all outcomes. Methods Randomized controlled trials (RCTs) which compared at least two TME strategies were identified by literature search of electronic databases of articles published to June 2018. Network meta-analysis with trial sequential analysis was performed using a frequentist approach with random-effects meta-analysis. We conducted a systematic search of PubMed, EmBase, the Cochrane Library, CNKI, and Web of Science. Titles and abstracts of the retrieved publications were independently and blindly assessed by two authors. Data collection and analysisResults Twenty-two RCTs with 4882 rectal cancer patients were included in this analysis. The trial sequential analysis demonstrated that the cumulative Z-curve crossed either the traditional boundary or the trial sequential monitoring boundaries, suggesting that OpTME resulted in a more complete TME specimen than LaTME (relative risk 1.05, 95% confidence interval 1.01-1.08). Network meta-analysis showed there was no significant difference in the other comparisons. Based on the P score of completeness of the TME specimen and circumferential resection margin positivity, the best technique was OpTME, followed by RoTME and then LaTME. However, this order was reversed when complications and mortality were considered. RoTME led to better lymph node harvest. Conclusions Although OpTME may give better pathological specimens, minimally invasive techniques may have advantages when considering lymph node harvest, complications and mortality. More RCTs are needed to determine which technique actually gives the best chance of survival.