Why Irrigate for the Same Contamination Rate: Wound Contamination in Pediatric Spinal Surgery Using Betadine Versus Saline.

Background: The risk of surgical site infection in pediatric posterior spine fusion (PSF) is up to 4.3% in idiopathic populations and 24% in patients with neuromuscular disease. Twenty-three percent of pediatric PSF tissue cultures are positive before closure, with a higher rate in neuromuscular patients. Our primary aim was to evaluate the feasibility of a complete randomized controlled trial to study the efficacy of surgical site irrigation with povidone-iodine (PVP-I) compared with sterile saline (SS) to reduce the bacterial contamination rate before closure in children undergoing PSF. Methods: One hundred seventy-five subjects undergoing PSF were enrolled in a multicenter, single-blind, pilot randomized controlled trial. We recruited patients at low-risk (LR) and high-risk (HR) for infection 3:1, respectively. Before closure, a wound culture was collected. Nonviable tissues were debrided and the wound was soaked with 0.35% PVP-I or SS for 3 minutes. The wound was then irrigated with 2 L of saline and a second sample was collected. Results: One hundred fifty-three subjects completed the protocol. Seventy-seven subjects were allocated to PVP-I (18 HR, 59 LR) and 76 to SS (19 HR, 57 LR). Cultures were positive in 18% (14/77) of PVP-I samples (2 HR, 12 LR) and in 17% (13/76) of SS samples (3 HR, 10 LR) preirrigation and in 16% (12/77) of PVP-I samples (5 HR, 7 LR) and in 18% (14/76) of SS samples (4 HR, 10 LR) postirrigation. Eight percent (3/37) HR subjects (1 PVP-I, 2 SS) experienced infection at 30 days postoperative. No LR subjects experienced infection. Conclusions: Positive cultures were similar across treatment and risk groups. The bacterial contamination of wounds before closure remains high regardless of irrigation type. A complete randomized controlled trial would be challenging to adequately power given the similarity of tissue positivity across groups.