Meta-analysis of natural orifice specimen extraction versus conventional laparoscopy for colorectal cancer.

objectiveTo compare natural orifice specimen extraction surgery (NOSES) and conventional laparoscopic (LAP) surgery in treating colorectal cancer.

methodsThe present authors conducted a systematic search in the PubMed, EMBASE, and Cochrane databases for randomized controlled trials (RCTs), prospective nonrandomized studies, and retrospective studies up to May 2019. We used postoperative complications as the main endpoints, and used hospital stay, time to first flatus, operative time, postoperative pain, cosmetic result, wound infections, and oncological outcomes as the secondary endpoints. Subgroup analyses were conducted according to the different specimen extraction sites (transanal and transvaginal). A sensitivity analysis was carried out to evaluate the reliability of the outcomes. RevMan5.3 software was used for statistical analysis.

resultTwelve studies (one RCT, ten retrospective studies, and one prospective nonrandomized study) involving a total of 1437 patients (NOSES group 665 patients and LAP surgery group 772 patients) were included. Meta-analysis showed that compared with LAP surgery, NOSES resulted in a shorter hospital stay (WMD = -0.79 days; 95% CI -1.17 to -0.42; P < 0.001; P = 0.02), a shorter time to first flatus (WMD = -0.58 days; 95% CI -0.75 to -0.40; P < 0.001), less postoperative pain (WMD = -1.51; 95% CI -1.99 to -1.04; P < 0.001), a better cosmetic result (WMD = 1.37; 95% CI 0.59 to 2.14; P < 0.001), and fewer wound infections (OR = 0.13; 95% CI 0.05 to 0.35; P < 0.001) and postoperative complications (OR = 0.48; 95% CI 0.36 to 0.65; P < 0.001). Oncological outcomes did not differ between the two groups, while the operative time (WMD = 13.95 min; 95% CI 4.55 to 23.35; P = 0.004) was longer in the NOSES group.

conclusionThe present systematic meta-analysis is an attempt to assess the impact of NOSES, namely, its oncological outcomes and surgical safety in colorectal cancer patients. Pooled comparisons revealed that NOSES was superior to LAP surgery in terms of postoperative morbidity, postoperative pain, hospital stay, the time to first flatus, cosmetic results, and wound infections; however, NOSES was associated with a longer operative time. Considering the abovementioned limitations and the very low level of evidence of the comparisons, further RCTs are required to verify the results of our study.