Comparative study on the use of commercial and snake venon derived fibrin sealant for reimplantation of spinal cord ventral roots following avulsion

Author(s)

Mateus Vidigal Castro

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2015-07-31

Examining board members

Alexandre Leite Rodrigues de Oliveira; Antonio de Castro Rodrigues; Valéria Paula Sassoli Fazan

• Advisor: Alexandre Leite Rodrigues de Oliveira

Abstract

Axonal injury in the interface of central nervous system (CNS) and peripheral (PNS) such as ventral roots avulsion (VRA) induce major retrograde degenerative processes which may cause neuronal death and loss of motor function. By this type of injury occurs the separation of nerve roots with the spinal cord, interrupting the contact between a motor neuron and the innervated muscle fibers. One promising treatment would be to use of fibrin sealants to redeploy the ventral root in their respective sites of avulsion, thereby promote the reconnection of motor neuron to the target organ, and therefore, return of functional. Currently fibrin sealants are used in a wide range of surgical procedures, including cardiovascular, thoracic, plastic and reconstructive, dental and neurosurgery. In the present research, we used two types of fibrin sealants to reconnect the ventral roots in the exact location of the injury. One of them, produced from the venom of Crotalus durissus terrificus other commercially produced to investigate the efficacy of both sealants to the nerve regeneration and motor recovery after avulsion of ventral spine roots. For this, Lewis rats female, 10 weeks old, were underwent to avulsion of ventral spinal root (L4-L6). These animals were divided in 3 groups: 1) avulsion of motor roots without reimplantation; 2) avulsion and reimplantation of motor roots with fibrin sealant derived from venom of Crotalus durissus terrificus on the spinal cord surface; 3) avulsion and reimplantation of motor roots with commercial fibrin sealant (Tissucol). The lumbar enlargement and sciatic nerve were dissected and samples processed for the investigation of neuronal survival and counting of myelinated axons as well as for analysis of histomorfometric parameters. Immunohistochemistry was used to evaluate synaptic stability, reactivity astroglial and microglial, beyond the expression of proteins related to axonal regeneration process. Additionally, the evolution of motor recovery was investigated using the "walking track test" (Catwalk). The results indicated that reimplantation of avulsion roots with both fibrin sealants significantly improved motor recovery up to 12 weeks postoperative. Moreover, the average number of axons and neuronal survival was also increased in the groups that received the reimplantation. Finally, reimplantation promoted partial preservation of synaptic coverage and increased expression of proteins related to axonal regeneration process. Furthermore, no differences in microglial reactivity and reactive astrogliosis in the acute phase after injury, among the experimental groups. Taken together, our results suggest that the derived fibrin sealant from venom of Crotalus durissus terrificus, as well as the commercial fibrin sealant (Tissucol), used for the reimplantation of spinal cord roots are similarly efficient, reimplanting the avulsion roots effectively, are neuroprotective and promoting the motor improvement (AU)

• FAPESP's process: 13/04409-0 - Comparative study on the use of commercial and snake venon derived fibrin sealant for reimplantation of spinal cord ventral roots following avulsion
• Grantee: Mateus Vidigal de Castro
• Support Opportunities: Scholarships in Brazil - Master