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Allografts
Allografts
Skin scaffolds provide a unique method to facilitate skin closure. They function through providing a dermal alternative to promote wound healing or create an environment that is amenable to skin grafting. Numerous options exist including Dermagraft (Organogenesis, Canton, MA), Integra (Intergra Lifescience, Plainsboro, NJ), and Apligraf (Organogenesis, Canton, MA) among many others.
Though each manufacturer provides unique recommendations regarding the product use, common themes and principles are involved in utilizing skin scaffolds. Prior to their use, a clean, hemostatic wound bed must be prepared. The scaffold may be applied with an overlying bolster or underlying vacuum-assisted closure to prevent fluid accumulation and facilitate integration. Weekly follow-up is undertaken. Typically wounds are covered with full- or split-thickness skin grafts at 3 weeks.51
Acceptable outcomes have been reported with placement directly onto bone and tendon. Multiple layers of these scaffolds can be used in order to restore soft-tissue contours in cases of large defects.52
Xenografts Bovine and porcine xenografts have been studied for healing wounds in human subjects. The most common type of xenograft used in repair of Mohs defects is porcine. Porcine xenograft confers the advantage of being a quick and technically simple repair; however the โgraftโ is not meant to โsurviveโ on the human body. Instead, the xenograft functions as a wound matrix to cover the wound bed and facilitate granulation and angiogenesis.53 Porcine xenografts may be fixed in place using absorbable sutures, and are bandaged as full-thickness skin grafts or hydrocolloid dressing (Figs. 45-27 and 45-28).
Figure 45-27. (A) Amelanotic melanoma of the palm removed by Mohs surgery. (B) Porcine xenograft reconstruction. (C) Early granulation. (D,E) Healing at 4 months without significant contraction.
Figure 45-28. (A) Defect after Mohs surgery. (B) Porcine xenograft sutured into place. (C) Final healing.