Intrawound vancomycin to prevent infections after spine surgery: a systematic review and meta-analysis.

Post-operative spine surgical site infections are associated with substantial morbidity, mortality, and economic burden. Intrawound vancomycin may prevent infections after spine surgery, but recent studies have reported conflicting results. The objectives of this systematic review and meta-analysis were to determine: (1) In patients undergoing spine surgery, does the application of intrawound vancomycin lead to reduced rates of post-operative surgical site infections? (2) Are there differences in the estimates of effect between observational studies and randomized trials? (3) What adverse events are reported in the literature? All published comparative studies of intrawound vancomycin in spine surgery were included. Two reviewers independently screened eligible articles and assessed study quality. Observational studies and randomized trials were pooled separately using a random-effects model. Eight observational studies and one randomized controlled trial met the inclusion criteria. Across observational studies, the odds of infection with intrawound vancomycin was 0.19 times the odds of infection without intrawound vancomycin (95 % CI 0.08-0.47, p = 0.0003, I (2) = 52 %). The single randomized controlled trial produced a conflicting result (OR 0.96, 95 % CI 0.34-2.66, p = 0.93). There were no adverse events attributable to intrawound vancomycin. The quality of the evidence was low or very low. There is a lack of high-quality evidence to inform the use of intrawound vancomycin in spine surgery. Surgeons should be cautious before widely adopting this intervention and should be vigilant in monitoring for adverse effects. Further investigation with additional randomized controlled trials is justified.