Vaginal preparation with povidone iodine or chlorhexidine before hysterectomy: a propensity score matched analysis

BACKGROUND Antiseptic vaginal preparation is recommended before gynecologic surgery; however, there is a lack of data regarding the effectiveness of different agents. OBJECTIVE To compare rates of postoperative infectious complications and hospital utilization with preoperative vaginal preparation using povidone-iodine or chlorhexidine before hysterectomy. STUDY DESIGN This was a retrospective analysis of patients who underwent hysterectomy for gynecologic indications at 70 hospitals in a statewide surgical collaborative between January 2017 and December 2019. The primary outcome was postoperative infectious complications (including urinary tract infection, surgical site infections involving superficial, deep, or organ space tissues, or cellulitis) within 30 days of surgery. To adjust for confounding, propensity score matching, 1:1 without replacement and with a caliper of.005 was performed to create cohorts that had vaginal preparation with either povidone-iodine or chlorhexidine and did not differ in observable characteristics. We compared the rates of infectious morbidity and hospital utilization (emergency department visits, readmission, reoperation) in the matched cohorts. RESULTS In the statewide collaborative, there were 18,184 patients who received povidone-iodine and 3018 who received chlorhexidine. After propensity score matching of 2935 pairs, the povidone-iodine and chlorhexidine groups did not differ in demographics, comorbidities, choice of preoperative antibiotics, benign vs malignant surgical indication, and surgical approach. Povidone-iodine was associated with a lower rate of infectious morbidity (3.0% vs 4.3%; P=.01), urinary tract infection (1.1% vs 1.7%; P=.03) and emergency department visits (7.9% vs 9.7%; P=.01) than with chlorhexidine. There were nonsignificant trends of lower rates of surgical site infection (2.0% vs 2.7%; P=.07) and reoperation (1.6% vs 2.1%; P=.18). CONCLUSION This propensity score matched analysis provides evidence that povidone-iodine is preferable to chlorhexidine for vaginal preparation before hysterectomy because of lower rates of infectious morbidity and fewer emergency department visits. However, the absolute differences in infectious morbidity rates were approximately 1%, and in the event of an iodine allergy, chlorhexidine appears to be a reasonable alternative.