The authors have developed a clinically relevant large-animal model of breast reconstruction using acellular dermal matrix. The acellular dermal matrix inflammatory, neovascularization, and tissue integration response should be evaluated in an in vivo setting that accurately simulates the anatomy, biomaterials, surgical techniques, and timeframes encountered in human postmastectomy breast reconstruction to appropriately predict clinical performance. Neovascularization of the acellular dermal matrix with detectable blood flow took place after postimplantation week 8, a much slower process than previously reported in models not clinically relevant to acellular dermal matrix-assisted tissue expander breast reconstruction.