Microbial Contamination-Mediated Inflammation Is a Major Contributor of Breast Implant Complications: Prospective...

Introduction: Breast reconstruction and breast augmentation via silicone breast implants are among the most commonly performed implant surgeries worldwide. However, these surgeries entail notable risks for postoperative implant complications, including implant rupture or capsular contracture. This study investigates the significance of microbial contamination regarding the development of peri-implant inflammation and its impact on implant-related complications. Methods: A total of 125 breast implant revisions in 97 patients with a history of breast cancer or prior cosmetic breast augmentation were analyzed at the Clinical Department of Plastic, Aesthetic, and Reconstructive Surgery, University Clinic of St. Poelten, between February 2021 and August 2023. Microbial contamination and subclinical inflammation were assessed using histological and microbiological analysis of implant surfaces and capsules. The implants were grouped by their initial indication for surgery, along with presence of contamination, inflammation, and complications, and then compared using a Chi² test, Fisher's exact test and two-sided t-tests. Results: Microbial contamination was found in 27 implants (21.6%), and 58 implants (48.74%) showed histological evidence of inflammation. Peri-implant inflammation was significantly more often observed in contaminated implants (p = 0.049). Implants displaying histological signs of peri-implant inflammation showed significantly higher rates of complications, particularly implant rupture (p < 0.001 each). In a subgroup analysis, cosmetic patients presented a significantly higher rate of peri-implant inflammation compared to breast cancer patients (p < 0.001). Cosmetic patients also showed significantly longer implant inlay times compared to breast cancer patients (14.32 vs. 3.76 years, p < 0.001), suggesting that prolonged implant inlay duration may contribute to the occurrence of peri-implant inflammation. Conclusion: Subclinical microbial contamination appears to accelerate the inflammatory reactions to silicone implants that subsequently increase the risk for complications and thus surgical removal. Additionally, prolonged implant inlay time seems to be a major independent contributor to chronic, low-grade inflammation, even in the absence of microbial contamination.