The Safety And Efficacy Of Nerve-sparing Radical Cystectomy:a Meta-analysis

Objective:To systematically and comprehensively evaluate the efficacy and safety of nerve-sparing radical cystectomy(NS-RC)in the treatment of bladder cancer.Methods:The literatures related to NS-RC in Chinese and English databases such as PubMed,Embase,Medline,Web of science,CNKI,Wanfang Database were searched by computer.The retrieval time was from January 2000 to December 2021.Two researchers cross-checked and screened out the kinds of literature that met the requirements of the meta-analysis by browsing the titles,abstracts,or full texts of literature,combined with the inclusion and exclusion criteria.Read through the full text and used the Jadad score and NOS score to evaluate the quality of the final screened literature,and then extracted the required data.Surgery-related indicators included operation time,intraoperative blood loss,severe postoperative complications,tumor recurrence and distant metastasis,cancer-related mortality within 2 years,erectile function at 6 months and 1 year after surgery,maximum urinary flow rate,Neobladder volume,residual urine volume,daytime and nighttime urinary continence within 1 year after surgery.Finally,use Review Manager 5.4.1 software to perform statistical analysis on relevant indicators.Results:A total of 986 relevant literatures were retrieved.After screened,12 literatures were included,consist of 4 prospective studies(1 RCT)and 8 retrospective studies,which quality score is from 5 to 8.The sample combine 822 cases totally,of which 484 cases in nerve-sparing group(NS)and 338 cases in the non-nerve-sparing group(NNS).The results of meta-analysis showed that operation time of NS group is 17.87 minutes shorter than that of NNS group(95%CI:-29.04～-6.69,P=0.002),but the heterogeneity is large,and the result is not robust.In NS group,the normal erection rate at 6 months after surgery is 13.1 times that of NNS group(95%CI:2.34～73.26,P=0.003),and at 1 year after surgery is 11.82 times that of NNS group(95%CI:4.38～31.90,P<0.0001).But I2>50%for both,after removing the heterogeneity in sensitivity analysis,the normal erection rate in the NS group at 6 months and 1 year after surgery is 5.86(95%CI:2.52～13.63,P<0.0001)and 6.45(95%CI:3.56～11.69,P<0.00001)times that of the NNS group respectively.Simultaneously,the NS group is 2.63 times(95%CI:1.46～4.72,P=0.001)and 2.05 times(95%CI:1.34～3.13,P=0.001)higher than the NNS group in terms of daytime urinary control rate and nighttime urinary control rate within 1 year after surgery.Combined with 2 research data show that the postoperative residual urine volume of NS group was 22.79ml less than that of NNS group(95%CI:-28.73～-16.86,P<0.00001).Because of the research data is less,credibility of the result is not high.In addition,there are no statistically significant differences in the intraoperative blood loss(P=0.14),the incidence of serious postoperative complications(P=0.9),the tumor recurrence and distant metastasis rates(P=0.07),the 2-year postoperative cancer-related mortality(P=0.17),the maximum postoperative urinary flow rate(P=0.34),and the neobladder volume(P=0.79)between NS group and NNS.Conclusion:This study analyzes the relevant outcome indicators of the safety and efficacy of NS-RC.The results show that compare with traditional radical cystectomy(RC),NS-RC can significantly improve the postoperative erectile function at 6-month and 1-year.And it can improve daytime and nighttime urinary continence within 1 year after the surgery.In terms of operation time and postoperative residual urine volume,the existing evidence could not make it clear that NS group is superior to NNS group.Meanwhile,there are no significant differences in intraoperative blood loss,postoperative serious complications,tumor recurrence and distant metastasis rates,cancer-related mortality within 2 years,maximum urinary flow rate,neobladder volume,and other related indicators,which illustrate that NS-RC don’t pose serious safety concerns.For patients who pursue the postoperative quality of life,NS-RC would be a better choice.Although this study is limited by factors such as less of RCTs and small sample size,it has reference significance for the development of related research.Overall,high-quality,large-sample,multi-center RCTs are still needed to verify the safety and efficacy of NS-RC.