The use of vancomycin powder in modern spine surgery: Systematic review and meta-analysis of the clinical evidence

Background Surgical-site infections (SSIs) can lead to greater postoperative morbidity, mortality, and health care costs. Despite current prophylactic measures, rates of SSIs have been reported in up to 15% of patients undergoing spine surgery. The adjunctive local application of vancomycin powder in spine surgery is a low-cost strategy to help reduce SSIs. Vancomycin is active against skin pathogens that can potentially contaminate the wound during spinal surgery. The local application of vancomycin in its powder form ensures adequate surgical-site concentrations while minimizing adverse effects caused by undetectable systemic distribution. However, clinical studies have produced conflicting results, and the clinical evidence behind the use of vancomycin powder in modern spinal surgery practices is not clear. Purpose To examine the current clinical evidence on the use of vancomycin powder in spine surgery. Study Design Systematic review and meta-analysis of literature. Methods A comprehensive search of the English literature was conducted with PubMed (MEDLINE). The inclusion criteria consisted of intrawound vancomycin powder use in spine surgery as a prophylactic agent for SSIs. Studies that investigated nonspine surgeries, selected patients on the basis of clinical suspicion, or included patients with infections were excluded. Studies that compared intrawound vancomycin in spine surgery against their standard practice were pooled in the meta-analysis using a random-effects model. Results A total of 671 abstracts were reviewed, and 18 papers met inclusion/exclusion criteria and were included in this review. These included 1 randomized controlled trial, 13 comparative studies, and 4 case series. The level of evidence in hierarchical order was as follows: 1 level II, 13 level III, and 4 level IV. Fourteen of the studies, 1 randomized controlled trial and 13 comparative studies, were eligible for the meta-analysis. The odds of developing a deep infection with intrawound vancomycin powder were 0.23 times the odds of experiencing an infection without intrawound vancomycin (95% confidence interval 0.11-0.50, P = 0.0002, I² = 47%). For combined superficial and deep infections the odds ratio was 0.43 (95% confidence interval 0.22-0.82, P = 0.01, I² = 36%). Conclusions Numerous clinical studies have confirmed the safety of using vancomycin powder in the surgical site. The pooled clinical data supports the use of vancomycin to prevent SSIs in adult spine surgeries. The majority of the supporting literature is class III evidence. Existing studies use different definitions for surgical site infections and different pre-, peri-, and postoperative antibiotic regimens. Further high-quality investigations should use standardized protocols to confirm these findings.