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. LEVEL OF EVIDENCE Level II-pilot randomized controlled trial.