Further evidence that human acellular dermal matrix decreases inflammatory markers of capsule formation in implant-based breast reconstruction.

[BACKGROUND] Human acellular dermal matrix (HADM; previously termed "acellular cadaveric dermis") may limit inflammatory changes believed to play a role in capsular contracture, a common complication of implant-based breast reconstruction.

[OBJECTIVES] Differences between HADM and native breast capsule specimens were evaluated by immunohistochemical analysis of key inflammatory markers involved in capsule formation.

[METHODS] Twenty consecutive patients underwent immediate, 2-stage, implant-based breast reconstruction with dual-plane HADM. During tissue expander-implant exchange, full-thickness biopsies of biointegrated HADM and native breast capsule (internal control) from the tissue-expander envelope were obtained. Immunohistochemical analysis was performed for endothelial cells (CD31), B cells (CD20), T cells (CD3), macrophages (CD68), collagen I and III, and myofibroblasts (α-smooth muscle actin). Observed levels of marker labeling were semiquantitatively scored from 0 (none) to 3 (severe) by a blinded histopathologist and were statistically analyzed with the Wilcoxon rank sum test.

[RESULTS] A bilateral sample was obtained from 1 patient; all other samples were unilateral. Compared with capsule samples from native breast tissue, HADM samples had significantly lower levels of all inflammatory markers (P < .001).

[CONCLUSIONS] These lower levels of inflammatory markers support previous evidence that HADM may inhibit inflammatory and profibrotic signaling characteristics of breast capsule development and decrease the risk of capsular contracture. Further investigation is needed to determine the mechanism by which HADM inhibits these inflammatory cells, whether HADM reduces the incidence of breast capsular contracture, and if so, the longevity of this effect.