Optimizing breast pocket irrigation: an in vitro study and clinical implications

Subclinical infections have been implicated in the etiology of capsular contracture. Intraoperatively, breast pocket irrigation with povidone-iodine or other antibiotic solutions has been popularized; however, detrimental effects on wound healing for these agents have been reported and their efficacy against common organisms found around breast implants has not been studied. The purpose of this study was to compare the in vitro efficacy of serial dilutions of povidone-iodine and two double antibiotic solutions DAB-1 (gentamicin/polymyxin B) and DAB-2 (gentamicin/cefazolin), against organisms most commonly found around breast implants. In phase I trials, serial dilutions of povidone-iodine and DAB were combined 1:1 with cultures of five common organisms found around implants. In phase II, povidone-iodine was serially diluted in DAB-1 rather than saline. In phase III, povidone-iodine was serially diluted with DAB-2. Efficacy for all phases was determined by plating the mixture onto agar plates and incubating at 37 degrees C for 48 hours. Povidone-iodine was 100 percent effective at a dilution of 12.5% against Staphylococcus epidermidis and 25% against Staphylococcus aureus but relatively ineffective against Escherichia coli and Pseudomonas, DAB-1 was found to be ineffective against S. epidermidis but effective against S. aureus, Propionibacterium acnes, E. coli, and Pseudomonas. In phase II trials, a concentration of 12.5% povidone-iodine in DAB was effective at killing all experimental bacteria. In phase III trials, 10% povidone-iodine in DAB-2 was effective at killing all bacteria tested. In conclusion, to maximize bacterial control of common breast implant organisms and to minimize the detrimental effects on wound healing, 10% povidone-iodine in gentamycin/cefazolin may be used with excellent results and its use clinically may reduce the incidence of capsular contracture.