181. Does Irrigation Solution Influence Surgical Site Infection Rates in Immediate Implant-based Breast Reconstruction?

PURPOSE: There is no universally accepted evidence-based best practice for irrigation at the time of implant-based breast reconstruction, with the optimal irrigation solution widely debated. Hypochlorous acid has been proposed as an alternative to traditional antibiotic or betadine-based formulations due to its robust antimicrobial characteristics with minimal cytotoxic or inflammatory effects on native tissues. This study aims to compare the effect of irrigation formulations on surgical site infection following implant-based breast reconstruction. METHODS: A multicenter retrospective cohort study was conducted on patients who underwent immediate implant-based breast reconstruction after mastectomy from January 2023 through July 2024. Patients who had a primary autologous reconstruction or delayed reconstruction were excluded from the study. The primary outcome assessed was surgical-site infection, which was defined as infections requiring either hospitalization for IV antibiotic management or operative wash-out, and explant. RESULTS: A total of 301 breast reconstructions were performed in 182 patients by 8 plastic surgeons and 9 breast surgeons, with 227 (75.4%) nipple sparing mastectomy procedures and 74 (24.6%) skin sparing mastectomy procedures. The mean age was 49.5 years (range, 22.7 to 83.1 years) and the mean BMI was 27.3 kg/m2 (range, 16.8 to 49.3 kg/m2). In this cohort, 25.2% received neoadjuvant chemotherapy, 33.2% received adjuvant chemotherapy, 3.9% received neoadjuvant radiotherapy, and 16.3% received adjuvant radiotherapy. The most common plane of reconstruction was prepectoral (81.4%), and 98.3% of reconstructions used a biologic matrix for implant support. Irrigation with 0.033% hypochlorous acid was performed in 77 (25.6%) breasts, double antibiotic (Ancef and Gentamycin) solution with betadine (5% povidone-iodine) in 108 (35.9%) breasts, double antibiotic solution alone in 82 (27.3%) breasts, and betadine solution alone in 34 (11.2%) breasts. Hypochlorous acid was associated with significant reduction in surgical site infection compared to double antibiotic solution alone (1.3% vs 8.5%, p<0.0349) and betadine solution alone (1.3% vs 8.8%, p=0.0189) but similar to double antibiotic solution with betadine (1.3% vs 4.6%, p=0.2067). The average follow-up was 6 months (range, 2 to 18 months). CONCLUSION: Irrigation with 0.033% hypochlorous acid may reduce the risk of surgical site infection in implant-based breast reconstruction while limiting the inflammatory reaction commonly seen with traditional antibiotic irrigation. Knowing this, surgeons may choose to utilize hypochlorous acid during implant-based reconstructive procedures, particularly in patients with a history of antibiotic sensitivity. Future research should be aimed at assessing the preventative antimicrobial properties of hypochlorous acid on subclinical infections with corresponding capsular contracture rates.