Evaluation of the efficacy of natural orifice specimen extraction surgery versus conventional laparoscopic surgery for colorectal cancers: A systematic review and meta-analysis.

Aim: Natural orifice specimen extraction surgery (NOSES) has gained significant importance in treating cancers. The current study is a meta-analysis that aimed to assess the short-term efficacy and long-term prognostic impact of NOSES and conventional laparoscopic (CL) surgery in the treatment of colorectal cancer (CRC).

Method: Published reports in several medical databases up to February 2024 were searched and information pertinent to outcomes of NOSES and CL in retrospective and randomized studies to treat CRC was collected. Pooled weighted/standardized mean difference (WMD/SMD), odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) were calculated using a fixed-effects model or random-effects model, and meta-analysis was subsequently performed using Stata.

Results: Thirty-one studies with a total of 4637 patients were included in this meta-analysis. When compared with CL, NOSES had significant advantages in several indicators, such as wound infection [OR = 0.22 (95% CI 0.13-0.38); Z = 5.56, p = 0], incisional hernia [OR = 0.24 (95% CI 0.11-0.54); Z = 3.44, p = 0.001], blood loss [WMD = -10.17 (95% CI -14.75 to -5.60); Z = 4.36, p = 0], incision length [WMD = -4.94 (95% CI -5.27 to -4.60); Z = 29.10, p = 0.00], postoperative pain [WMD = -1.43 (95% CI -1.69 to -1.18); Z = 11.02, p = 0.00], use of additional analgesics [OR = 0.57 (95% CI 0.39-0.82); Z = 3.06, p = 0.002], hospital stay [WMD = -1.25 (95% CI -1.58 to -0.93); Z = 7.65, p = 0.00], gastrointestinal recovery [WMD = -13.42 (95% CI -17.77 to -9.07); Z = 6.05, p = 0.00], first flatus [WMD = -0.50 (95% CI -0.68 to -0.32); Z = 5.34, p = 0.00] and cosmetic result [WMD = 2.11 (95% CI 0.92-3.30); Z = 3.47, p = 0.001]. However, NOSES required a significantly longer duration of surgery [WMD = 14.13 (95% CI 6.70-21.56); Z = 3.73, p = 0.00]. There were no significant differences in postoperative anastomotic leakage, intra-abdominal infection, lymph node harvest, proximal and distal margins, 5-year disease-free and 5-year overall survival and pelvic floor function.

Conclusion: NOSES is considered an efficient surgical method of treatment for CRC that allows patients to have long-term favourable oncological outcomes while recovering faster with minimal pain. However, these findings still require confirmation through studies on large population cohorts.