Sensory Recovery After Skin Graft Using Allogenic Dermis

ABSTRACT

It is well known that the thicker dermis is grafted, the lesser adhesion and contracture can be resulted. In spite of all advantages, thicker layer of dermis can also cause pain, infection, hypertrophic scar and delayed healing at the donor site. In addition, full thickness skin graft can result in best quality in recipient site, but it is limited in donor site and harvested size. Processed allogenic dermis(Alloderm(R)) has been developed and applied to solve the above-mentioned problems as permanent dermal augmentation for full thickness skin defect. From March 2002 to December 2003, we have applied allogenic dermis (Alloderm(R)) and ultra-thin split thickness skin graft on 30 patients (Group A) who had hypertrophic scar, 3rd degree burn, full thickness skin defect and various cosmetic problems. The control patients (Group B) are treated by conventional autologous thick split thickness skin graft only. We evaluated wound contracture, degree of sensory recovery, color change, functional and histological aspect between Group A and B. In Group A, by providing a dermal augmentation, the grafted dermal matrix permitted a thin autograft from the donor site. The harvested ultra-thin split-thickness skin remained fewer complications on the donor site and had faster healing process. And allogenic dermis exhibited excellent elastisity and good pigmentation with minimal scarring and wound contracture. But in sensory reinnervation study, Group A was not fully recovered compared to the conventional skin graft in Group B. In histological study, small nerve fiber bundles are scattered in the mid-dermis of processed allogenic dermis in Group A, but in Group B nerve fiber bundles extended into the upper dermis. Most nerve fibers were not sufficiently innervated into upper dermis in allogenic dermis because it was assumed that allogenic dermis play an important role as a barrier. In conclusion, if we perform ultra-thin split thickness skin graft using an allogenic dermis, wounds can be covered in a single stage with an adequate layer of dermal augmentation with minimal donor site morbidity, and we can also get good functional recovery, and avoid undesirable complications. However, application of allogenic dermis in the important area of sensation, such as hands and feet, should be conservative at present. Further scientific refinement is necessary for the improvement of sensory recovery in using allogenic dermis and a large scale experimental study should be performed.