Comparison of Effects of Acellular Dermal Matrix and Latissimus Dorsi Muscle Flap on Radiation-induced Peri-implant Capsular Contracture in a Rabbit Model

Backgrounds: Capsular contracture of breast implants is a major complication of breast surgery. Clinically, covering a breast implant with acellular dermal matrix or autologous tissue is considered to be the most effective technique to prevent capsular contracture. This study was designed to clearly compare the protective effects of acellular dermal matrix and latissimus dorsi muscle flap placement on capsular contracture by increasing the rate of capsular contracture through controlled radiation exposure in a rabbit model. Methods: Twenty New Zealand white rabbits were divided into three groups. After the implant was placed beneath the pectoralis major muscle, the lateral third of the implant was left exposed in the control group (n=6). In the acellular dermal matrix group (n=7), the exposed implant was covered with AlloDerm. In the latissimus dorsi flap group (n=7), the exposed implant was covered with a pedicled latissimus dorsi muscle flap. All groups were irradiated 3 weeks after implant insertion. After 6 months, peri-implant tissues were harvested and analyzed. Results: Acellular dermal matrix showed markedly lower myofibroblast activity than the latissimus dorsi flap. However, transforming growth factor β1 levels and the activity of collagen types I and III produced in fibroblasts were significantly lower in the acellular dermal matrix group than in the latissimus dorsi flap group. Conclusions: Based on the findings of our rabbit experiments, acellular dermal matrix is expected to have a comparative advantage in reducing the risk of capsular contracture compared to the latissimus dorsi flap.