180 Optimal Neurosurgical Surgical Site Preparation: A Prospective Single-Center Study

INTRODUCTION: Surgical site infections (SSI) can be devastating, yet optimal preparation techniques have not been clearly determined in neurosurgical patients. Furthermore, the profile and origin of pathogens that ultimately go on to cause SSI remain unclear. METHODS: This is a prospective single-center study including adult patients undergoing elective procedures. Cultures are taken before and after preparation with providone iodine (PVI), chlorhexidine gluconate (CHG), or a combination based on surgeon preference, and again from bone after exposure. Primary outcome is SSI requiring return to the OR. Secondary outcomes are the effects of preparation on surgical site cultures, and the correlation between cultures and ultimate infectious pathogens. RESULTS: The study includes 846 patients undergoing open procedures. 692 cases used CHG, 96 PVI, and 58 both. 11 SSIs required return to the OR with an infection rate of 1.3%. 6 had used CHG (0.9%), 5 PVI (5.2%) during the index surgery. 67 additional patients underwent endoscopic endonasal procedures with PVI prep and no infections. The infection rate for PVI was significantly higher than CHG (p = 0.01), even among matched procedures (p = 0.03). Among the index surgeries with complete surgical site culture data, the causative organism was never present. We found that pathogens present in the first culture but not the second were sometimes present in the third cultures, consistent with the hypothesis that there is a bacterial reservoir in hair follicles inaccessible to skin prep. CONCLUSIONS: CHG reduces the rate of SSI. The pathogens that go on to cause infection are not present on the skin at the time of surgery, and thus that causative organisms are introduced into the wound at a later time. This raises important questions about the optimal care of neurosurgical wounds postoperatively.