A new anesthetic protocol to medullary nerve roots access in rats.

Deivid Ramos Dos Santos,Nayara Pontes De Araújo,Tiago Braga Duarte,Renan Kleber Costa Teixeira,Faustino Chaves Calvo,Rosa Helena De Figueiredo Chaves,Letícia Amanda Pinheiro De Ataíde,Rui Sergio Monteiro De Barros

doi:10.1590/acb360908

Abstract

ABSTRACTPurpose:To describe a new anesthetic protocol medullary and nerve roots access and in Rattus norvegicus.Methods:Seventy female Wistar rats (n=70) were used. The animals were randomly divided into two laminectomy groups: cervical (n=40) and thoracic (n=30). In cervical group, a right posterior hemilaminectomy was performed to access the nerve roots. In thoracic group, a laminectomy of the eighth thoracic vertebra was accomplished. Thirty-five rats (20 cervical and 15 thoracic) were submitted to old anesthetic protocol (ketamine 70 mg/kg plus xylazine 10 mg/kg); and the 35 other animals (20 cervical and 15 thoracic) were submitted to a new anesthetic protocol (ketamine 60 mg/kg,xylazine 8 mg/kg and fentanyl 0.03 mg/kg).Results:The time to complete induction was 4.15 ±1.20 minin ketamine, xylazine and fentanyl group, and it was 4.09 ±1.47 min in the ketamine and xylazine group. There was no correlation in the time required to perform the cervical laminectomy in the old anesthetic protocol. In all groups, the animals submitted to the old anesthetic protocol had a higher level of pain on the first and third postoperative days than the animals submitted to the new anesthetic protocol.Conclusions:The new anesthetic protocol reduces the surgical time, allows better maintenance of the anesthetic plan, and brings more satisfactory postoperative recovery.

Highlights

Spinal nerve avulsion injuries are devastating both from the functional and the psychosocial points of view, due to poor neural regeneration, especially the preganglionic lesions, that, as a rule, have the worst prognosis owing to their considerable failure rate[1,2,3]
There was no correlation in the time required to perform the cervical laminectomy in the old anesthetic protocol
The animals submitted to the old anesthetic protocol had a higher level of pain on the first and third postoperative days than the animals submitted to the new anesthetic protocol

Summary

Introduction

Spinal nerve avulsion injuries are devastating both from the functional and the psychosocial points of view, due to poor neural regeneration, especially the preganglionic lesions, that, as a rule, have the worst prognosis owing to their considerable failure rate[1,2,3]. They occur when the nerves that connect the spinal cord to the muscles are arranged (avulsed). As root avulsion is a longitudinal injury to the spinal cord, it differs from other peripheral nerve injuries and is beyond surgical repair[3,4]. In the last 20 years, in only some experimental models, it has been reported that avulsioned root nerve neurotization is possible by reimplantation of the injured root in the spinal cord[5,6]

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Conclusion