Exploring The Potential Of Acellular Dermis Grafts For Wound Healing And Soft Tissue Repair
Offering insights from the literature, practical pearls and coding tips, this author discusses the use of acellular dermis grafts for foot and ankle applications including wound healing, tendon and ligament repair and soft tissue supplementation.
Allogenic dermis grafts have been used for many years, traditionally as temporary wound cover in burn and other large wounds. Newer acellular versions, processed to remove the cellular components, are gaining in popularity and usefulness in numerous clinical applications. More recent clinical uses involve use of the graft as a scaffold allowing for new tissue ingrowth, adding structural support to soft tissues, or to act as a filler or spacer. Foot and ankle applications include wound healing (diabetic ulcers and others), tendon and ligament repair, soft tissue supplementation, and joint resurfacing.
Classically, skin grafts are obtained from the patient (autograft) as full or partial-thickness skin grafts. Donor site morbidity limitations and durability concerns of the healed skin, especially for thin split-thickness skin grafts, have previously restricted use.
Fresh frozen donor dermis grafts (allograft) originally applied to severe burn wounds were used as temporary covers only due to issues of antigenicity and subsequent graft rejection.
Acellular dermis grafts (a.k.a. acellular dermal matrix grafts) are derived from cadaveric (donor) skin. Much like the fresh frozen donor grafts, their original purpose was to serve as a cover for exposed periosteum in severe burn wounds.1 Acellular dermis grafts, however, are processed to remove living cells to greatly reduce the risk of rejection. These grafts have inherent favorable attributes which optimize their usefulness in different clinical scenarios.
The structure of the graft facilitates ingrowth of new tissue allowing the graft to serve as a scaffold. These acellular dermis grafts have a reticular side (derived from deeper dermal layers) which facilitates revascularization and new tissue ingrowth. The preservation of vascular channels present in the deeper dermal tissues particularly aid rapid revascularization. This is regardless of the recipient tissue type.
Some of the more commonly encountered brands of acellular dermis grafts include: GraftJacket (meshed) (KCI), Alloderm (LifeCell), GraftJacket (non-meshed) (Wright Medical Technology), hMatrix (Bacterin Biologics), DermaSpan (Biomet) and TheraSkin (Synthes).2-5
A wide variety of other graft materials have been in use for wound healing and soft tissue repair. Xenografts include OrthAdapt (Synovis Life Technologies), CuffPatch (Biomet) and Restore (DePuy).6 Synthetic grafts include Integra (Integra Life Sciences) and Marlex (Bard). Skin substitutes include Dermagraft (Shire Regenerative Medicine) and Apligraf (Organogenesis).6-8
Xenografts have applications similar to acellular dermis grafts. They have the ability to act as scaffolds and have significant tensile strength.8,9 Since these grafts are of animal origin, significant rejection risk exists.9,10
Other grafts may not act as a scaffold but serve other purposes. Grafts such as Integra provide temporary wound cover, allowing undisturbed healing below the graft. Skin substitutes such as Dermagraft and Apligraf facilitate healing via release and/or promotion of the release of growth factors to stimulate wound healing.7