Laser doppler perfusion imaging of skin territory to reflect autonomic functional recovery following sciatic nerve autografting repair in rats.

Peripheral nerve repair requires comprehensive evaluation of functional outcomes of nerve regeneration; however, autonomic nerve function is seldom evaluated probably due to lack of suitable quantitative methods. This study sought to determine whether autonomic functional recovery could be reflected by cold-induced vasodilation (CIVD) within target skin territory, as monitored by laser Doppler perfusion imaging (LDPI). Rats with sciatic nerve defect injury received autologous nerve grafting, and the plantar surface of the hind feet was subjected to LDPI analysis following nerve repair. The results indicated that at 3 and 6 months after autologous nerve grafting, the plantar surface of the hind foot exhibited the same level of CIVD as contralateral normal side, whereas rats in nerve defect group (negative control) showed significantly reduced CIVD. In addition, suitable nerve regeneration and functional recovery were achieved as assessed by pain sensation tests as well as electrophysiological and immunohistological examinations. Based on the potential influence of local autonomic nerve signals on CIVD, it was possible to evaluate functional recovery of autonomic nerves by using LDPI measurements of dermal CIVD.