OBJECTIVETo analyze the influence of topical application of nerve growth factor (NGF) on nerve ending regeneration of large skin grafts in patients.

METHODSSixty wounds from 48 adult patients with small or moderate burn area and scar excision were randomly divided into NGF and control groups, with 30 wounds in each group. The wounds in control group were treated with simple saline solution, while those in NGF group, the graft was first wrapped in a piece of gauze holding 100 ml saline solution containing 9000 AU NGF before operation, and then flushed with same amount of NGF saline underneath skin after application of the graft. From 20 post-operative day on, NGF was injected at multiple points every other day for one month. In control group, only normal saline was used. The texture of the graft, pain sensation, temperature and two - point discrimination, BMRC grade were observed for 12 months. Skin specimens were obtained from 6 wounds in control group, 5 wounds in NGF group, and 4 specimens from normal skin for immunohistological examination of protein gene product 9.5 (PGP 9.5), synaptophysin (SYN), and neuron specific enolase (NSE). The nerve endings regeneration and distribution were also observed.

RESULTSCompared with those in control group, each index of feeling recovered earlier and better in NGF group, with better two - point discrimination ratio and BMRC grade. One year after operation, 17 skin grafts in NGF group reached S4 grade, with two - point discrimination ratio of 1.11 +/- 0.14, while only 5 grafts in control group reached S4 grade, with two - point discrimination ratio of 1.56 +/- 0.73. Six months after operation, rich nerve endings, with integral adnexae were observed in microvascular bed of skin - graft region and tissue interspace around fibromas tissue in subcutaneous tissue in NGF group, while nerve endings were found to be scanty and slender in subcutaneous tissue in control group.

CONCLUSIONLocal application of NGF can promote nerve regeneration and sensory recovery of grafted skin.