Reconstitution of basement membrane after 'sandwich-technique' skin grafting for severe burns demonstrated by immunohistochemistry

Abstract

Reconstitution of basement membrane structures after "sandwich-technique" grafting of severe deep burns is demonstrated with use of immunohistochemical techniques. Cryosections of human skin after epifascial burn wound excision and sandwich grafting were stained with monoclonal antibodies against type IV and VII collagen, polyvalent antiserum against type VI collagen, and polyvalent antibody against laminin. Standard hematoxylin and eosin histologies were performed for morphologic correlation. Reorganization of the mesenchymal border zone (basement membrane), after transplantation of extremely expanded split-thickness skin autografts overlaid with glycerolized split-thickness skin allografts onto debrided human full-thickness wounds, occurred from day 5 to day 35. The autografts reepithelize the spaces between the mesh structure, which has been covered primarily exclusively with allogenic skin, and form a layered squamous epithelium, with an underlying three-dimensional basket-weave array of collagen in the remodeled neodermis after epifascial excision. Immunochemical techniques detect the reconstitution of a basement membrane zone with a typical architecture and distribution of laminin, type IV, and type VII collagen being built up 1 week to 5 weeks after sandwich grafting. These structures can be seen in the autografts during the first 2 weeks and are consistent in the whole reconstituted skin after day 35. To our knowledge this is the first report of the expression of type VI collagen in these types of wounds. The findings are compared with the expression of type VI collagen in healthy skin. The results indicate that the modified sandwich-grafting technique is an adequate means for early burn wound closure and resurfacing of third-degree burn wounds and leads to the reconstitution of dermal qualities.