TREATMENT OF CHRONIC WOUNDS WITH CULTURED SKIN SUBSTITUTES - A PILOT-STUDY

Chronic wounds in skin persist because the normal process of wound hea ling is obstructed. Failures occur in the inflammation and proliferati on phases of wound healing that reduce formation of granulation tissue and prevent epithelial migration to close the wound, resulting mostly from vascular insufficiencies of multiple etiologies. Microbial conta mination of chronic wounds also contributes importantly to the persist ence of venous stasis, diabetic, and decubitus ulcers. Although slow h ealing can be stimulated by regular debridement and cleaning of chroni c wounds, acceleration of epithelial closure has been demonstrated by application of sheets of cultured allogeneic keratinocytes. These stud ies have been extended by attachment of allogeneic keratinocytes to an implantable collagen-based sponge that is populated with cultured all ogeneic fibroblasts. Because chronic wounds have low vascular competen ce and high probability for microbial contamination, skin substitutes are irrigated topically with a solution of nutrients and antimicrobial agents until epithelial engraftment. Initial case reports show that a llogeneic epithelium can cover chronic wounds within seven to ten days , protective epithelium forms within one month, and long-term wound cl osure is accomplished, most probably by ingrowth of autologous epithel ium. With this approach, cultured skin substitutes may be expected to promote healing of chronic wounds that have sufficient vascular compet ence to remain perfused. Together with surgical and non-surgical appro aches to improvement of vascular function, cultured skin substitutes o ffer an alternative therapy for accelerated closure of chronic wounds.