Intrawound application of vancomycin for prophylaxis in instrumented thoracolumbar fusions: efficacy, drug levels, and patient outcomes

Abstract

Study design: A retrospective cohort study from a single institution of a consecutive series of spine surgery patients.

Objective: To evaluate the safety and efficacy of adjunctive local application of vancomycin for infection prophylaxis in posterior instrumented thoracic and lumbar spine wounds compared to IV cephalexin alone.

Summary of background data: Cephalosporin resistant strains of staphylococcus (MRSA and coagulase negative staph) have diminished the efficacy of intravenous antibiotic prophylaxis for instrumented spine fusion. Intravenous vancomycin prophylaxis has not been shown to decrease wound infection rates compared to IV cephalosporins. Adjunctive application of vancomycin powder in wounds for instrumented spinal fusion surgery may decrease infection rates.

Methods: Since 2000, 1732 consecutive thoracic and lumbar posterior instrumented spinal fusions have been performed with routine 24 hours of perioperative intravenous antibiotic prophylaxis with cephalexin. Since 2006, 911 of these instrumented thoracic and lumbar cases had 2 g of vancomycin powder applied to the wound before closure in addition to intravenous antibiotics. A retrospective review for infection rates and complications was performed. Oswestry and SF-36 outcomes instruments were completed before surgery, immediately after surgery, and at latest follow-up. The average follow-up is 2.5 years, range 1 to 7 years.

Results: Eight hundred twenty-one posterior instrumented thoracic and lumbar fusions were preformed using intravenous cephalexin prophylaxis with a total of 21 deep wound infections (2.6%). Coag negative staph was the most commonly isolated organism. Nine hundred eleven posterior instrumented thoracic and lumbar fusions have been performed with IV cephalexin plus adjunctive local vancomycin powder with two deep wound infections (0.2%). The reduction in wound infections was statistically significant (P < 0.0001). There were no adverse clinical outcomes or wound complications related to the local application of vancomycin.

Conclusion: Adjunctive local application of vancomycin powder decreases the postsurgical wound infection rate with statistical significance in posterior instrumented thoracolumbar spine fusions.