Intrawound vancomycin powder for prevention of surgical site infections after open instrumented posterior spinal fusion (VANCO Trial)-methodology of a randomized, controlled, multicenter study.

Background: Surgical site infections (SSIs) after instrumented spine fusion surgery may occur in up to 12% of cases and lead to increased morbidity, mortality, and healthcare costs. Numerous retrospective studies suggest the use of intrawound vancomycin powder in spine surgery to be protective against SSIs. The use of intrawound vancomycin powder is controversial, and there is a paucity of well-designed prospective trials evaluating its safety and efficacy in spine surgery. The objective of the VANCO Trial is to evaluate the safety and efficacy of intrawound vancomycin powder in open instrumented spine fusion surgery to prevent SSIs.

Methods: The VANCO Trial is a multicenter, 1:1 randomized superiority trial with a total of 7 recruiting spine institutions in Switzerland. Adult patients scheduled for an open spinal fusion procedure will be screened for eligibility. Randomization of participants will take place intraoperatively before wound closure. Patients randomized into the treatment arm will receive 1-2 g of vancomycin powder (depending on length of skin incision: ≤ 20 cm vs. > 20 cm), which will be administered above the closed muscle fascia (suprafascially-subcutaneously) before wound closure. The main outcome and measure is the rate of superficial and deep SSIs within 90 days following surgery.

Discussion: The VANCO Trial is one of the first clinical trials to evaluate the safety and efficacy of intrawound vancomycin powder in a selected spine surgery population. Routine administration of intrawound vancomycin powder in selected spine surgery patients could fundamentally advance international standards for reducing SSIs.

Trial registration: ClinicalTrials.gov NCT04017468.