Evidence-based recommendations for spine surgery

Effect of intrasite vancomycin powder on development of epidural fibrosis

Placement of vancomycin powder into the surgical wound prior to closure has been shown to reduce postoperative infections in spine surgery. This study examines the effect of vancomycin powder on formation of epidural fibrosis (EF). Twenty-two rats underwent a two-level lumbar laminectomy. A control group, a low-dose and a high dose vancomycin powder (applied prior to closure) group was formed. Rats were sacrificed at 30 days and a blinded fellowshiptrained pathologist evaluated the laminectomy segments for EF. 50% of the samples in the high-dose vancomycin group were EF grade 3, compared to 20% of the low-dose and 16.7% of control samples. The average fibrosis grade for the high dose, low dose and control groups were 2.4, 1.4 and 1.8, respectively. There were more grade 3 EF specimens in the high dose vancomycin group. While the average EF grade was also higher in this group, there was not a statistical difference compared with the other groups.

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, I(2) = 47%). For combined superficial and deep infections the odds ratio was 0.43 (95% confidence interval 0.22-0.82, P = 0.01, I(2) = 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.