A Systematic Review and Bayesian Network Meta-Analysis: Short-Term and Long-Term Outcomes of Three Surgery Procedures Following Neoadjuvant Chemoradiotherapy for Rectal Cancer.

Our aim was to perform a Bayesian network meta-analysis of short-term and long-term outcomes of open surgery (OS), laparoscopic surgery (LS), and robotic surgery (RS) after neoadjuvant chemoradiotherapy (nCRT) for rectal cancer. We searched randomized controlled trials (RCTs) and non-RCTs published up to October 2018 from PubMed, Embase, Cochrane Library, and Web of Science. We selected studies referencing the comparison between at least two of OS, LS, and RS. Short-term and long-term outcomes of different surgery procedures were evaluated. Mean differences or odds ratios and their 95% credible interval were pooled with Bayesian modeling. In the network meta-analysis, 15 studies were identified through database searching and other sources that included three RCTs and nine non-RCTs enrolling 2360 patients. As for long-term outcomes, we did not find any significant difference among these surgery procedures after nCRT for rectal cancer in this network meta-analysis. As for short-term outcomes, no significant outcomes were obtained except for operative time, blood loss, length of incision, and time to pass first flatus. Our meta-analysis illustrated that RS had the longest operative time. However, LS had a significantly shorter operative time than RS, shorter incision than OS, shorter time to pass first flatus than OS, and less blood loss than OS. RS was regarded as the inferior surgery procedure after nCRT for rectal cancer. Meanwhile, LS might possibly be the most safe and feasible surgery procedure after nCRT for rectal cancer.