Reinnervation of human skin grafts: a histochemical study

The reinnervation of nine human skin grafts was investigated using histochemical thiocholine methods for the demonstration of cholinesterases. The regenerated cutaneous nerves showed both specific acetylcholinesterase and nonspecific cholinesterase reactions. In the youngest specimens, taken 3 weeks after the grafting, such regenerated nerves were seen both at the subdermal level under the graft and at the margins of the graft. These nerves seemed to orient toward the denervated graft area. The growing nerves were generally distributed in a random fashion. The reinnervation of some hair follicles, erector pili muscles, and sweat glands were observed in well-innervated full-thickness and thick partial-thickness skin grafts. It is suggested that this target-organ control of regenerating nerves occurs as a result of the action of chemotactic factors. A well-innervated graft bed seems to be important for optimum reinnervation of skin grafts. Fibrosis and scarring seem to hamper nerve regeneration.