Comparison of the effects of PRP and hyaluronic acid in promoting peripheral nerve regeneration An experimental study with vascular conduit model in rats'.

Aim: Peripheral nerve defects generally occur due to mechanical, chemical, thermal and pathologic causes and the reconstruction is still a challenging problem. In the present study, we aimed to compare the effects of platelet rich plasma (PRP) that has high levels of growth factors and hyaluronic acid (HA) that is known to have positive effects on nerve regeneration by decreasing scar formation in a rat model where they were injected through allogeneic aorta graft in peripheral nerve defects using histopathologic and functional methods.

Material And Methods: The study involved 20 Wistar Albino male rats that weighed 200 to 250 grams and aged about 1 year old. Of the rats, two were used as donor for PRP and aorta graft harvest. Three random groups of 6 rats were composed. In all of the groups, the left sciatic nerves were used and 1 cm of defects were created. The right sciatic nerves were used as control groups. Group 1 was the group repaired with autograft, Group 2 was the group repaired with HA injected through aorta graft and Group 3 was the group repaired with PRP injected through aorta graft. The findings were evaluated in terms of functional (electromyography and walk test analysis) and histopathologic parameters at 12 weeks.

Results: In all of the groups varying degrees of axonal regeneration was observed. Group 1 was the closest group to the control group showing highest rate of nerve regeneration followed by Group 3 where PRP was injected through aorta graft and group 2 where ha was used respectively.

Conclusion: The study demonstrates that PRP enhances peripheral nerve regeneration more than HA when used in a vascular conduit model.

Key Words: Hyaluronic acid, Peripheral nerve regeneration, PRP.