Efficacy of Intrawound Treatments to Prevent Surgical Site Infection after Spine Surgery: A Systematic Review and Network Meta-analysis.

BACKGROUND Intrawound treatments have been reported to have favorable efficacy for preventing surgical site infection (SSI); however, the best strategy remains unknown. OBJECTIVE The aim of this systematic review and network meta-analysis was to evaluate the efficacy of intrawound treatments to prevent SSI after spine surgery. STUDY DESIGN A systematic review and network meta-analysis. METHODS We searched the Cochrane Library, EMbase, PubMed, Chinese Science and Technology Periodical Database (VIP), China National Knowledge Infrastructure (CNKI), and Wanfang Data from the date of inception to March 2, 2020. The randomized controlled trials (RCTs) and cohort studies were identified and extracted by 2 reviewers independently. We performed a traditional pairwise meta-analysis to evaluate overall efficacy of intrawound treatments. Meanwhile, a network meta-analysis was performed to compare and rank the treatment efficacy using frequentist approach. RESULTS Thirty-three publications (6 RCTs and 27 retrospective cohort studies) were included, involving 22,763 patients. For pairwise meta-analysis, the combined results showed that the intrawound treatment had a significantly lower SSI rate than the control group (CG) (odds ratio [OR] = 0.41; 95% confidence interval [CI], 0.31-0.55). For network meta-analysis, the treatment of vancomycin (VA) (OR = 0.53; 95% CI, 0.39-0.71), povidone-iodine (PI) (OR = 0.10; 95% CI, 0.04 - 0.23), and vancomycin + povidone-iodine (VA+PI) (OR = 0.25; 95% CI, 0.11-0.58) were found to be significantly more efficacious than CG on reduction of SSI rate. PI ranked first on reducing SSI, followed by PI+HP, VA+PI, gentamicin (GM), VA, and hydrogen peroxide (HP); CG ranked last. LIMITATIONS Firstly, only 6 RCTs are included in this systematic review. Retrospective cohort studies tend to exaggerate the real results, although most of them are high-quality according to the Newcastle-Ottawa Quality Assessment Scale (NOQAS). More high-quality RCTs need to be included to obtain convincing conclusions. Secondly, the population of this study involves both adult and pediatric cohorts, patients with tumor, congenital disease, or degenerative disease. There is no subgroup analysis for ages and type of diseases, which might have influence on the overall pooled analysis. Thirdly, we define the application of saline solution and no intrawound treatment as the control group, which might ignore their heterogeneity. Fourthly, follow-up periods are variable and the sample size of HP is small. Finally, additional research is needed to compare the complications of different treatments and the benefits of various dosages. CONCLUSION We found that VA and PI show promising results on reducing SSI. PI is recommended as the most efficacious intrawound treatment to prevent SSI after spine surgery.