Difference in the occurrence of capsular contracture according to the characteristics of the tissue in an irradiated rat model.

Abstract

In this study, it was hypothesized that the capsule formation varies according to the radiation dose in the muscle tissues; chest wall tissues, including the ribs; and acellular dermal matrices (ADM) that are in contact with the silicone implant. This study consisted of 20 SD rats that underwent submuscular plane implant reconstruction using ADM. They were divided into four groups: Group 1 as the un-radiated control (n = 5), Group 2 with non-fractionated radiation at a dose of 10 Gy (n = 5), Group 3 with non-fractionated radiation at a dose of 20 Gy (n = 5), and Group 4 with fractionated radiation at a dose of 35 Gy (n = 5). Three months after surgery, hardness was measured. Moreover, the histology and immunochemistry of the capsule tissues of the ADM, muscle tissues, and chest wall tissues were analyzed. As the radiation dose increased, the silicone implant became harder. But no significant difference in capsule thickness according to the radiation dose was observed. Based on the tissue in contact with the silicone implant, ADM has a thinner capsule thickness than the muscle tissues and less inflammation as well as less neovascularization compared with the other tissues. This study described a new rat model of clinically relevant implant-based breast reconstruction using a submuscular plane and ADM with irradiation. Therefore, it was confirmed that the ADM in contact with the silicone implant, even after irradiation, was protected from radiation compared with the other tissues.