Histopathological Study of Meshed Versus Solid Sheet Acellular Dermal Matrices in a Porcine Model

Background Acellular dermal matrices (ADMs) are commonly used to support implant-based breast reconstruction. However, there is little comparative data on the incorporation process of different ADMs, and the value of meshing or fenestration versus solid sheet has not been established, although early clinical data suggest seroma rates may be reduced. This was a preclinical assessment of the incorporation process at optimal conditions in a pig model. Methods SurgiMend and AlloDerm matrices were implanted in subcutaneous pockets on the backs of 15-week-old female pigs. Half of the samples were meshed 1:2.5; the remainder was grafted as a fenestrated (SurgiMend) or solid sheet (AlloDerm). Tissues were harvested at 3 months. Histological slides were prepared for hematoxylin and eosin staining, and Masson trichrome and immunostaining with anticollagen type I fluorescein isothiocyanate stain. Histological parameters (inflammation, giant cell reaction, neovascularization, fibroplasias, and scar tissue formation) were graded blindly on a scale of 0 (no reaction) to 3 (severe reaction). Results All explanted ADMs (SurgiMend, n = 23; AlloDerm, n = 20) were firmly incorporated within the host tissue. SurgiMend showed more fibroplasia (P = 0.029) compared with AlloDerm in meshed or solid sheet form. Meshed ADMs showed a trend toward increased inflammation (P = 0.074) and giant cell reaction (P = 0.053) compared with solid sheet/fenestrated ADM. Conclusions Meshing ADM may allow cells to populate matrices more rapidly, promoting integration compared with solid sheet ADMs. This study sets the histological basis for further clinical investigations, with the aim of demonstrating lower complication rates (and particularly reduced seroma formation) with meshed ADMs.