Regenerating effects of platelet-rich plasma and bone marrow aspirate on sciatic nerve injuries in dogs

Abstract

In dogs, the sciatic nerve is prone to damage from pelvic fractures due to trauma, or from internal fixation of pelvic fractures due to iatrogenic injury. It had been the goal of previous studies to find a way to accelerate nerve regeneration functionally. The present study aimed to investigate the effects of platelet-rich plasma (PRP) and bone marrow (BM) aspirate on the functional healing of surgically severed sciatic nerve in dogs after its end-to-end anastomosis. Fifteen adult healthy mongrel dogs of both sexes were included in this study. They had been anesthetized and prepared for aseptic surgery as usual. The sciatic nerve was exposed midway between the ischiatic tuberosity and the sacrococcygeal joint. It was severed and anastomosed by end-to-end fashion using three to four interrupted stitches. Dogs were then randomly allocated into three groups; A, B, and C. In group A (control), the sutured nerve was left without treatment. In group B, 1 ml of PRP was injected into the epineurium and around the nerve at the suture site. In group C, 1 ml of BM aspirate was injected into the epineurium and around the nerve at the suture site. In all groups, the muscular incision, subcutis, and skin were sutured routinely. Animals were evaluated at monthly intervals for 3 months through the recording of physiological parameters, neurological examination findings (postural reactions, and spinal reflexes), and laboratory examination, while the histopathological examination was carried out at the end of study. Data were statistically analyzed and expressed as mean ± SEM. Differences were statistically significant at P<0.05. The results showed a moderate degree of lameness, persistent knuckling, and dropped hock in the control group (A). The dogs of the PRP group (B) did not show lameness, knuckling, or dropped hocks. There was a slight degree of lameness, intermittent knuckling, and occasional dropping of the hock in the BM group (C). There were significant differences in hopping, extensor thrust, between groups A and both groups B and C but the righting reaction was varied substantially between groups A and C. There was not a significant variation in the biochemical tests between different groups except the creatine kinase, which was high in the BM group relative to PRP and control groups. Histopathological examination revealed variations between groups in the architectural pattern of the repaired nerves, which was better in the PRP group. It could be concluded that the addition of the PRP and BM aspirate to the injured nerve after its suturing promotes the healing microscopically with little functional improvement within months. Platelet rich plasma and Bone marrow aspirate are useful biological materials when are used in the acute injury or rupture of the peripheral nerves in animals.