INTRODUCTION
Dehydrated human amnion chorion membrane (dHACM) allografts, such as EpiFix and AmnioFix among others, are synthetic skin substitutes derived from placental tissue. Comprised of an epithelial layer and 2 fibrous connective tissue layers, dHACM allografts function to repair lost or damaged dermal tissue. Healthy dermal tissue typically contains the extracellular matrix (ECM), which is made up of collagen, fibroblasts, proteoglycans, elastin, hyaluronic acid, fibronectin, and other components, all of which play a role in wound healing. dHACM allografts, derived from sterilized and dehydrated placental tissue, contain many of the components found in the ECM of the dermis, which makes them beneficial for wound healing.1
dHACM allografts are harvested from donors following cesarean section and thoroughly screened for infectious or viral diseases. They are comprised of 3 layers, the amnion, the chorion, and the intermediate layer separating the 2. The amnion, the side typically facing the fetus, is comprised of an epithelial layer with a fibroblast layer that contains types I and III collagen, contributing to the tissue's strength.2 The amnion also contains other components of the ECM, including laminin and fibronectin, which contribute to the stroma and basement membrane.2 The intermediate layer separates the amnion from the chorion and contains many nutrients such as glycoproteins. Lastly, the chorion layer, the side that contacts maternal tissue, is comprised of multiple layers that contribute to both the strength of the tissue and have nutrients that promote cell growth.3 Altogether, the amniotic membrane consists of an epithelial layer and 2 fibrous connective tissue layers that contain important components of the ECM including fibroblast growth factor, platelet-derived growth factor, transforming growth factor-beta 1, and multiple interleukins. These components contribute to the wound healing properties of the human amnion chorion membrane.
dHACM allografts are harvested from donors following cesarean section and thoroughly screened for infectious or viral diseases. They are comprised of 3 layers, the amnion, the chorion, and the intermediate layer separating the 2. The amnion, the side typically facing the fetus, is comprised of an epithelial layer with a fibroblast layer that contains types I and III collagen, contributing to the tissue's strength.2 The amnion also contains other components of the ECM, including laminin and fibronectin, which contribute to the stroma and basement membrane.2 The intermediate layer separates the amnion from the chorion and contains many nutrients such as glycoproteins. Lastly, the chorion layer, the side that contacts maternal tissue, is comprised of multiple layers that contribute to both the strength of the tissue and have nutrients that promote cell growth.3 Altogether, the amniotic membrane consists of an epithelial layer and 2 fibrous connective tissue layers that contain important components of the ECM including fibroblast growth factor, platelet-derived growth factor, transforming growth factor-beta 1, and multiple interleukins. These components contribute to the wound healing properties of the human amnion chorion membrane.
dHACM allografts have been shown to improve the healing of tissue of the skin, cornea, ligaments, and periodontal tissue, among others. Common uses of dHACM allografts include the healing of diabetic and non-diabetic foot and leg ulcers, decubitus ulcers, and wounds following debridement. Patients receiving dHACM allografts for chronic leg ulcers due to venous insufficiency or diabetic nervous system degeneration tend to have poor circulation. This lack of blood flow leads to decreased delivery of nutrients required for wound healing, increased scarring of tissue, and increased risk of infection.
