Chlorhexidine gluconate vs povidone-iodine vaginal antisepsis for urogynecologic surgery: a randomized controlled noninferiority trial

BACKGROUND: Although povidone-iodine (iodine) is the only Food and Drug Administratione approved vaginal antiseptic solution, there is a lack of comparative data evaluating alternatives. Chlorhexidine gluconate is readily accessible, recommended by multiple societies as an alternative for patients with iodine allergy, and preliminary data indicate that it may provide superior antisepsis. OBJECTIVE: This study aimed to compare the effectiveness of chlorhexidine and iodine as presurgical vaginal antiseptic solutions in preventing the most common surgery-associated infection after gynecologic surgery, urinary tract infections. STUDY DESIGN: We conducted a randomized controlled noninferiority trial among women undergoing urogynecologic surgery. The primary outcome measure was symptomatic urinary tract infection within 2 weeks after surgery. The secondary outcomes included culture-proven urinary tract infection at 2 and 6 weeks after surgery, symptomatic urinary tract infections at 6 weeks after surgery, any surgical site infection at 2 weeks after surgery, and patient-reported vaginal irritation after surgery. We required 58 participants per arm to demonstrate noninferiority of chlorhexidine vs iodine (margin of relative risk of <1.5 for the upper limit of 95% confidence interval) between groups for the primary outcome. RESULTS: A total of 119 participants (61 in the chlorhexidine group and 58 in the iodine group) completed the primary outcome and were included in the analyses. There was no difference in the groups' demographic characteristics, medical history, operations performed, or perioperative factors. Chlorhexidine was not inferior to iodine concerning the primary outcome, symptomatic urinary tract infection at 2 weeks after surgery (10% vs 17%; relative risk, 0.6; 95% confidence interval [-N, 1.3]). Furthermore, chlorhexidine was not inferior to iodine for the secondary urinary tract infection outcomes (culture-proven urinary tract infection at 2 and 6 weeks after surgery and symptomatic urinary tract infection at 6 weeks after surgery). Groups were similar in terms of surgical site infection (overall 3/119 [2.5%]) and presence of any vaginal irritation (4/54 [7.4%], for both groups). CONCLUSION: Chlorhexidine was not inferior to iodine for vaginal antisepsis before urogynecologic surgery concerning urinary tract infection. Given the similar postoperative urinary tract infection rates demonstrated in this study and the lack of difference in vaginal irritation, chlorhexidine seemed to be a safe and reasonable option for vaginal antisepsis before surgical procedures. Additional studies are needed to further examine surgical site infection.