Peripheral nerve repair with nerve growth factor and fibrin matrix

Abstract

A fibrin sealant matrix (FS) with or without a nerve growth factor (NGF) has been used to improve the recovery of severed peripheral nerves, and these have been compared with the results of using only the standard epineural suture (SUT). Regeneration in the early phase (up to 6 days) was measured by the pinch test. The functional recovery process (up to 12 weeks) was evaluated by serial gait track analysis. Longitudinal sections of the nerve specimens were submitted to immunohistochemical staining with monoclonal antibody against neurofilament. In addition, the release of the NGF from the NGF-FS matrix in vitro was investigated by ELISA. The regeneration of the leading sensory fibers was significantly faster in both FS groups (with and without NGF) than in the SUT group at 3 and 4 days postoperatively. The behavioural data expressed by the sciatic function index (SFI) and the toe spreading index (TSI) indicated significant improvement in NGF-FS group at the 9th week postoperatively (p<0.05). Histologically, good and excellent outgrowth of neurites was encountered in both the NGF-FS and FS groups, while most of the results from SUT group were poor to satisfactory. In vitro, a peak of NGF release was seen within 18 h; afterwards, release remained slow for two weeks. It has been concluded that local application of a combination of FS and NGF may be useful for neuritic regeneration and subsequent functional recovery; the fibrin matrix itself may be beneficial for neuritic sprouting in the early phase.