Safety and oncological outcomes of natural orifice specimen extraction surgery compared with conventional laparoscopic surgery for right hemicolectomy: a systematic review and meta-analysis

Natural orifice specimen extraction surgery (NOSES) is a new technique and uses natural orifice as the delivery route for specimen extraction to avoid supererogatory incision, and the safety and oncological outcomes of NOSES for right hemicolectomy are still inconclusive, so a meta-analysis was performed to compare these to conventional laparoscopic surgery (CLS). Related literature comparing NOSES with CLS for right hemicolectomy, whether randomized controlled trials (RCTs) or retrospective studies, were systematically searched. A random-effect model or fixed-effect model was used based on the I 2 value. A total of six studies (all retrospective trials) involving 609 participants were included. Compared with CLS, NOSES was more preponderant than CLS in terms of surgical morbidity [odds ratio (OR) = 0.31; P = 0.0002], length of hospital stay [weighted mean difference (WMD) = − 1.52; P = 0.006], time to first flatus (WMD = − 0.82; P = 0.0008) and liquid intake (WMD = − 1.40; P