Abstract
Introduction
Skin graft survival relies on imbibition, inosculation, and revascularization from the wound bed. When a wound bed is poorly vascularized, as in the case of exposed fascia, tendon or bone, skin grafting may be delayed until the wound bed improves. We propose that topical nutrient supplementation may be able to increase take of skin grafts applied over an avascular wound bed.
Methods
Twenty full-thickness 5cm-diameter wounds were created on the dorsum of anesthetized swine and a dermal substitute (0.4mm, 0.8mm, 1.2mm, or 1.6mm thick) was placed on each wound. Negative pressure therapy with and without intermittent (3x per day) saline instillation was applied. Wounds were analyzed using a non-contact 3D camera at day 7 and day 14.
Results
Dermal substitutes of 0.8mm, 1.2mm, and 1.6mm thicknesses inhibited graft take significantly (p< 0.01, p=0.02, p< 0.01, respectively) for all wounds treated with wound vac alone. Addition of the normal saline instill showed a significant improvement in graft take (p=0.03) over wound vac alone for the wounds treated with the 0.8mm dermal substitute. Wounds covered with 1.2mm and 1.6mm dermal substitute continued to show significantly decreased graft take (p=0.03 and p=0.02, respectively). Wounds with 0.4mm dermal substitute showed similar graft take to control for both the wound vac and wound vac + instill treatments.
Conclusions
Dermal substitutes ≥0.8mm create a successful model of an avascular wound bed. Vac + instill treatment overcame the impedance of an avascular wound bed only for the 0.8mm dermal substitute thickness. This thickness of dermal substitute creates an ideal avascular wound bed model from which to conduct further studies incorporating topical nutrients instilled directly onto skin grafts placed onto avascular wound beds.
Applicability of Research to Practice
Single-stage skin grafting procedures onto avascular wound beds may become feasible with topical nutrient supplementation providing the environment to maintain graft survival until the wound bed is able to support the skin graft.
Treatment of Leg Chronic Wounds with Dermal Substitutes and Thin Skin Grafts
