Effect of Platelet Rich Plasma and Platelet Rich Fibrin on sciatic nerve regeneration in a rat model.

The aim of this study was to evaluate the effect of Platelet Rich Plasma (PRP) and Platelet Rich Fibrin (PRF) on peripheral nerve repair. Thirty-two Wistar rats were randomly divided into four equal treatments groups: autologous nerve grafts (ANG), silicon tube plus saline solution (SS), silicon tube plus PRP, and silicon tube plus PRF. In ANG group, 10 mm segment from sciatic nerve was excised and reimplanted between the nerve stumps. In the SS, PRP, and PRF groups, 5 mm segment from sciatic nerve was excised and bridged with a 12 mm silicone conduit to create a 10 mm nerve gap. The conduit was filled in accordance with the different treatments. Walking track analysis was performed periodically and on the 90th post-operative day histomorphometric analysis was performed. The ANG, PRF, and PRP groups presented a significant functional improvement in relation to the SS group (P = 0.001) on 90 days after surgery. Histomorphometric analysis demonstrated that the ANG group achieved a larger nerve fiber diameter in proximal stump while comparing with the SS group (P =0.037) and showed larger fiber diameter in median stump in comparison to the PRP group (P = 0.002) and PRF group (P = 0.001). Axonal diameter and myelin sheath thickness showed no statistical significant difference between the groups in the three stumps (P ≥ 0.05). This study suggests that PRP and PRF have positive effects on the functional nerve recovery; however, these groups don't achieve a significant improvement on the histomorphometric analysis.