The effect of guidance channel on sciatic nerve repair in adult rats

Peripheral nerve lesions are a challenge for neurosurgeons and different surgical repairing methods are applied for the treatment of this problem. This study was conducted to evaluate the poled polyvinelidene fluoride (PVDF) tube filled with nerve growth factor (NGF) and collagen gel as a substitute for nerve autograft.

In this experimental study the left sciatic nerve was manipulated in 50 male Wistar rats and then the animals were divided randomly into five groups. In the epineural group the injured nerves were repaired by end to end suture. In the rats with autograft a 10 mm piece of sciatic nerve was rotated through 180° and sutured in the nerve gap. In the nerve guidance channel group (NGC), polarized piezoelectric PVDF tube containing NGF and collagen gel was replaced in the gap and in the axotomy group two nerve ends were hidden among muscles. The left sciatic nerve was exposed but not transected in the sham group. After two months L4-L6 segment neurons of spinal cord were studied histologically and by immunohistochemical and axonal DiI tracing. The collected data were analyzed by one way ANOVA, LSD and paired t- test.

The mean number of Bax positive cells and labeled motor neurons increased significantly in axotomy and sham group respectively, compared to the other groups (P<0.05). Also, the mean number of labeled motor neurons increased significantly in epinural group in comparison to the autograft and the NGC groups (P<0.05). There was no significant difference in the mean number of the labeled neurons between the autograft and nerve guidance channel groups. The mean number of motor neurons in the left side showed a significant decrease in comparison to that of the right side (p<0.01).

The PVDF tube together with other therapies provided a favorable environment for nerve regeneration and could be used as a substitute for autograft in nerve injuries.