Skin grafts and tissue replacement can be used to treat foot ulcers in people with diabetes by reconstructing the skin defect. Skin substitutes need to be placed on a prepared wound bed to ensure contact between the wound bed and the graft and they take on the functions of the missing skin layer. Before the skin substitute is applied ulcers are usually rinsed and debrided to remove hyperkeratinised (abnormally horny or thickened skin) or necrotic tissue. The method of clinical application of the graft/tissue replacement and the frequency of application depends on the specific product used. Some skin substitutes are designed for temporary wounds coverage and some as a permanent replacement.
Different types of skin grafts and tissue replacements are currently available. These are generally divided into the following categories: autografts (taken from the patient), allografts (taken from one person, given to another) and xenografts (taken from animals), and bioengineered tissue or artificial skin. They are used in a number of ways.
- Autografts: skin taken from the patient and placed directly in the bed of the target ulcer (e.g. split‐skin or full‐thickness skin from pinch or mesh grafts).
- Allografts and xenografts: skin taken from other humans or animals with a similar skin structure, placed directly in the bed of the target ulcer.
- Bioengineered or artificial skin: skin replacement products created in a laboratory from cultures of skin components and cells (e.g. fibroblasts or keratinocytes), and then placed in the bed of the target ulcer.
Grafting and tissue replacement of allogeneic skin are associated with some risk of transmission of infections such as hepatitis or the human immunodeficiency virus (HIV). Even with screening for these diseases in donors, this risk is not eliminated entirely.