Can A New Biologic Matrix Facilitate Improved Wound Healing?
First, one would debride the wound site free of all necrotic tissue in order to expose a viable and vascular wound bed. If there is exposed bone, curette it to stimulate a small amount of bleeding. Then irrigate the site with a pulse lavage technique and copious normal saline solution. Control bleeding with traditional methods or topical thrombin.
As with split thickness skin grafts, the presence of hematoma will lift the graft off the recipient bed and prevent incorporation of the Integra into the wound bed. The graft is usually meshed 1.5:1 or perforated with a scalpel to avoid hematoma and seroma formation. It is imperative that the graft rest on a clean, well vascularized bed of tissue to promote neovascularization. If the blood supply to the wound bed is poor, vessels will not incorporate into the Integra matrix and the template will fail. Also be aware that placing Integra on a heavily contaminated wound bed can potentially convert an open colonized wound into a closed wound abscess. If you are concerned about the wound base, obtain culture samples. One may place Integra over deep wound tissues including bone, fat, fascia, tendon and muscle.
When applying the Integra graft to the wound site, clinicians should ensure it is cut to fit accurately within the excised wound margins. Note the orientation of the graft and ensure that the collagen-glycosaminoglycan dermal layer is in direct contact and adherent to the wound bed with no air spaces occluding graft contact. Place the silicon layer (identified by the black marker threads) away from the wound so this forms the superficial protective layer. Secure the graft to the wound margins with several staples or sutures.
One can then dress the graft with a non-adherent dressing (Mepitel, Adaptic, Tegapore) and subsequently use an antibacterial barrier dressing layer (Acticoat, Actisorb). One may then employ a secondary dressing or consider applying negative pressure (i.e. VAC therapy).
The non-adherent layer will serve to prevent premature disruption of the graft during dressing changes. The antibacterial layer will protect from infection and decrease wound contamination, and the negative pressure will stimulate graft adherence and angiogenesis while reducing the incidence of seroma and hematoma.
Multiple clinical studies show that burn wounds treated with Integra progress to normal re-growth of papillary and reticular dermis without scar formation. Studies comparing Integra versus epidermal autografts for the treatment of burn patients show the Integra dressing has a higher percentage of take. Integra take rates are reportedly between 80 and 87 percent. The reported success rate of overlying split thickness skin grafts on top of the Integra generated dermis is 85 percent.
While there is only minimal experience and data in using Integra for complicated diabetic foot wounds, there appears to be significant promise. The product has minimal logistical concerns since it is not a living tissue and can help build a viable wound matrix in problem and deep wounds in the lower extremity.
Dr. Steinberg (pictured) is a faculty member of the Department of Surgery at the Georgetown University School of Medicine in Washington D.C.