PERIPHERAL NERVE REGENERATION ON AN ARTIFICIAL NERVE (BIODEGRADABLE NERVE GUIDE TUBE)

Aim: The aim of this study was to reveal the regeneration profile both pathologically and physiologically. Methods: The biodegradable tube made of polygycolic acid (PGA) tube and collagen sponge with a diameter of 5 mm was used. In eight beagle dogs, a 10-mm segment of the right isciadic nerve was resected distal from the isciadic notch. And the resulting defect was reconstructed with the tube. As a control, autografting (i.e. resected graft used reversed) was performed on four beagle dogs. Pathological recovery was observed on the longitudinal sections at one to three months. Functional recovery was analyzed with electro-physiological method both motor and sensory neurons. Gate pattern was analyzed with the computer system. The longest observation was 720 days. Results: Pathologically, nerve tissue regenerated from both side in initial stage. Axonal elongation was observed from proximal end and passed through the reconstructed site at two months. The rate of the axonal regeneration was faster in the tube than in autograft. After twelve months gate disturbance on the reconstructed side recovered well. At 450 days the EMG was recognized on the M. gastrocunemius and M. tibialis anterior. The amplitude was almost same and latency was about 150% of normal side. Conclusion(s): This biodegradable nerve guide promoted the nerve regeneration which may the reason of the earlier recovery on the nerve tube than that on autografts.