Free sensate secondary skin flaps: an experimental study on patterns of reinnervation and neovascularisation

The main purposes of the present study were: 1) to compare differences, if any, in the patterns of reinnervation between secondary skin flaps, created either from "innervated skin grafts" or from ordinary denervated skin grafts; 2) to examine the influence of time, and the possible roles of granulation tissue and fibrosis in reinnervation following implantation of a nerve trunk into a secondary skin flap at different stages; and 3) to compare neovascularisation before and after free transfer of these flaps. Neurovascular changes were studied in a rat model by microangiography and by immunohistochemical techniques, using antisera to protein gene product 9.5 (panneural marker), to calcitonin gene-related peptide (sensory neurones) and to von Willebrand Factor (endothelial cell marker). The results indicate a potential clinical role for secondary sensate skin flaps where conventional methods of reconstruction including free neurovascular flap transfers are not available.