Characterization of microbial presence at the surface of silicone mammary implants.

The purpose of this project was to examine the incidence of microbial presence on the surface of mammary implants and its correlation with clinical presentation. The significance of microbial presence without signs of overt infection is questioned. Several issues are raised, including whether the presence of micro-organisms may immunize the host, trigger autoimmune reactions, or locally change the course of healing (resulting in capsular contracture). A total of 150 explanted silicone mammary implants from 87 patients were cultured. Cultures of 81 devices were positive (54%); the predominant isolate was Staphylococcus epidermidis (found on 68 implants, or 84%). Bacteria were detected on 76% (62 of 82) of implants surrounded by contracted capsules and on 28% (19 of 68) of those without capsular contracture (p < 0.05). Among 40 patients (46%) who had no general health problems, 11 (28%) had positive cultures of explanted devices (15 of 62 explants, or 24%). In the remaining 47 patients (54%) who complained of myalgia (77%), arthralgia (68%), chronic fatigue (38%), skin rashes (21%), cognitive problems (19%), dry mucosal membranes (19%), episodes of low-grade fever (17%), and hair loss (13%), 38 (81%) had positive cultures (66 of 88 explants, or 75%) (p < 0.05). The hypothesis that capsular contracture or problems that might be related to chronic infection and immunization are associated with subclinical infection is supported by this study.