Implementation of parameters in the expansion ratio of mesh skin grafts.

Expansion of a mesh skin graft depends on factors pertaining to the graft itself as well as on parameters of the meshing device. With regard to the graft, we examine the efficiency of graft handling and thickness of the skin graft. With regard to the parameters of the meshing apparatus, which determine the expansion ratio: (1) d equals the distance between the cutting blades, which will become the width of the mesh ribbons and is an underestimated parameter for expansion; and (2) L equals the length of cut, which determines proportionally the expansion ratio. This length defines the maximal distance of the raw square of the expanded mesh and therefore the healing time by epithelialization. The authors present a mathematical formula of expansion ratio that allows for an objective comparison of skin meshing apparatuses. It is concluded that optimal mesh skin grafting is based on mathematical principles rather than on inventive instrumentation. Furthermore, an analysis of the mechanical parameters as given by the manufacturers is important in anticipating healing time per expansion ratio.