Comment on: “Comparison of intracorporeal and extracorporeal anastomosis and resection in right colectomy: a systematic review and meta-analysis”

Abstract

We recently read the meta-analysis by Zheng et al. titled "Comparison of intracorporeal and extracorporeal anastomosis and resection in right colectomy: a systematic review and meta-analysis" published in the September issue of Langenbeck's Archives of Surgery [1]. The authors are commended for a well-written paper involving 30 studies with 4317 participants. However, we would like to communicate some of the methodological concerns regarding this paper.Firstly, the authors utilized the Newcastle-Ottawa scale for quality assessment of all the included studies in this meta-analysis. The Newcastle-Ottawa scale was developed to appraise the quality of observational studies; therefore, it is inappropriate to use it for randomized control trials (RCTs) [2]. We suggest the authors to separately assess the quality of randomized control trials using the Cochrane Collaboration's Risk of Bias (ROB) Tool [3]. Secondly, as described in the Cochrane Handbook for Systematic Reviews, RCTs and observational studies cannot be combined unless the results are related to the harmful/adverse effects of the intervention [4]. Therefore, it is a methodological error to combine RCTs with observational studies in this meta-analysis. A better approach is to make a subgroup analysis of RCTs and observational studies for all the outcomes. Thirdly, high heterogeneity was observed in results of several study outcomes (surgical duration I 2 = 83%, intraoperative blood loss I 2 = 81%, number of harvested lymph nodes I 2 = 71%, incision length I 2 = 95%, hospitalization duration I 2 = 87%, time to first fluid I 2 = 98%, and time to first defecation I 2 = 98%), thus affecting the reliability of conclusions reached. Sadly, the authors did not discuss the * Muhammad Ali Tariq