Surgical complications associated with hemilaminectomy and intervertebral disc fenestration: Prospective study of 64 dogs / Complicações associadas à hemilaminectomia toracolombar e fenestração de disco intervertebral: estudo prospectivo em 64 cães

ABSTRACT: Hemilaminectomy and intervertebral disc fenestration are commonly used to treat intervertebral disc extrusion (IVDE); however, they are associated with surgical complications. Sixty-four dogs were assessed during the intraoperative, immediate postoperative, and late postoperative periods to evaluate complications resulting from these surgical procedures. During this study, 15.62% (n=10) of the dogs presented with complications during at least one of the evaluations. Iatrogenic rhizotomy, access to the spinal canal contralateral to the lesion, and cardiorespiratory arrest were observed intraoperatively. Abdominal wall flaccidity, neurological worsening, hematoma, dehiscence, and superficial wound infections were observed during the immediate postoperative period. Adverse reactions to the surgical thread, scar adhesion, and superficial wound infection were the most frequent complications during the late postoperative period. Dogs that undergo hemilaminectomy and intervertebral disc fenestration because of IVDE may experience complications during the intraoperative, immediate postoperative, and late postoperative periods. However, these complications are often transitory and rarely cause death.

RESUMO: A hemilaminectomia e a fenestração do disco intervertebral são os procedimentos cirúrgicos geralmente empregados no tratamento da extrusão do disco intervertebral (EDIV), os quais podem desencadear complicações cirúrgicas. Foram avaliadas complicações em 64 cães nos períodos intra e pós-operatório imediato e tardio. Dos pacientes incluídos no estudo, 15,62% (n=10) apresentaram alguma ocorrência em pelo menos uma das etapas avaliadas. Das complicações, no período intraoperatório foram observadas rizotomia iatrogênica, abertura do canal vertebral contralateral e parada cardio-respiratória. No pós-operatório imediato foram verificadas a flacidez da parede abdominal lateral, piora neurológica, hematoma, deiscência de ferida cirúrgica e infecção superficial da ferida de pele. No pós-operatório tardio foram verificadas reação ao fio cirúrgico, aderência cicatricial e flacidez da parede abdominal lateral como problemas mais frequentes. Conclui-se que cães submetidos à hemilaminectomia e fenestração do disco intervertebral envolvido em decorrência da EDIV podem apresentar complicações nos períodos intraoperatório, pós-operatório imediato e tardio, sendo transitórias e com mínimas chances de ocasionar óbito.

Tridimensional models and radiographic study of dorsal laminectomy and thoracolumbar hemilaminectomy in dogs

Purpose: To create three-dimensional anatomical models of the thoracic and lumbar portions of the canine spine that reproduce the vertebral surgical approaches of dorsal laminectomy and hemilaminectomy, and to perform the respective radiographic evaluations of each approach. Methods: In a digital archive of the canine spine, digitally replicate the dorsal laminectomy and hemilaminectomy in the thoracic and lumbar portions and, then, make tridimensional prints of the vertebral models and obtain radiographs in three dorsoventral, ventrodorsal and laterolateral projections. Results: The anatomical models of the surgical spinal canal accesses of the thoracic and lumbar portions showed great fidelity to the natural bones. The created accesses have the proper shape, location and size, and their radiographic images showed similar radiodensities. Conclusions: The replicas of the dorsal laminectomy and hemilaminectomy developed in the anatomical models in the thoracic and lumbar portions are able to represent the technical recommendations of the specialized literature, as well as their respective radiographic images, which have certain radiological properties that allow to make a deep radiological study. Therefore, the models are useful for neurosurgical training.

Biomechanical study of partial lateral corpectomy with or without an association with pediculectomy and hemilaminectomy in canine specimens / Estudo biomecânico de corpectomia lateral parcial com ou sem associação com pediculectomia e hemilaminectomia em espécimes caninos

The present objective was to increase the number of biomechanical cycles performed using non-chondrodystrophic dog specimens, based on the study by Araújo (2017), comparing partial lateral corpectomy (PLC) alone, corpectomy and pediculectomy, and PLC associated with pediculectomy and hemilaminectomy to determine if there are significant differences between them regarding deformation versus applied force. Groups were divided as: control (G1), corpectomy (G2), corpectomy +pediculectomy (G3), and corpectomy + pediculectomy + hemilaminectomy (G4). The level of displacement versus force was observed during axial compression, flexion, extension, right and left lateral bending, and right and left axial rotation. Significant differences were observed between groups for flexion, extension, right and left axial rotation, and left lateral bending, whereas there was no difference for axial compression and right lateral bending. PLC and PLC with pediculectomy had significant differences in flexion and in extension, similar to PLC associated with pediculectomy and with hemilaminectomy in right and left axial rotation, flexion, extension, and right lateral bending.

O presente objetivo foi, a partir de grupos de espécimes caninas não condrodistróficas, aumentar o número de ciclos biomecânicos realizados, com base no estudo de Araújo (2017), comparando-se corpectomia parcial lateral (CPL) isolada, corpectomia e pediculectomia, à CPL associada à pediculectomia e à hemilaminectomia, no intuito de determinar se há diferenças significativas entre eles quanto à deformação versus à força aplicada. Os grupos foram divididos em: controle (G1), corpectomia (G2), corpectomia + pediculectomia (G3) e corpectomia + pediculectomia + hemilaminectomia (G4). O nível de deslocamento versus a força foi observado durante a compressão axial, a flexão, a extensão, a flexão lateral direita e esquerda e a rotação axial direita e esquerda. Observaram-se diferenças significativas entre os grupos para flexão, extensão, rotação axial direita e esquerda e flexão lateral esquerda, ao passo que, na compressão axial e na flexão lateral direita, não houve diferença. CPL e CPL com pediculectomia tiveram diferenças significativas na flexão e na extensão, semelhantemente à CPL associada à pediculectomia e à hemilaminectomia nos movimentos de rotação axial direita e esquerda, flexão, extensão e flexão lateral direita.

Surgical complications associated with hemilaminectomy and intervertebral disc fenestration: prospective study of 64 dogs / Complicações associadas à hemilaminectomia toracolombar e fenestração de disco intervertebral: estudo prospectivo em 64 cães

Hemilaminectomy and intervertebral disc fenestration are commonly used to treat intervertebral disc extrusion (IVDE); however, they are associated with surgical complications. Sixty-four dogs were assessed during the intraoperative, immediate postoperative, and late postoperative periods to evaluate complications resulting from these surgical procedures. During this study, 15.62% (n=10) of the dogs presented with complications during at least one of the evaluations. Iatrogenic rhizotomy, access to the spinal canal contralateral to the lesion, and cardiorespiratory arrest were observed intraoperatively. Abdominal wall flaccidity, neurological worsening, hematoma, dehiscence, and superficial wound infections were observed during the immediate postoperative period. Adverse reactions to the surgical thread, scar adhesion, and superficial wound infection were the most frequent complications during the late postoperative period. Dogs that undergo hemilaminectomy and intervertebral disc fenestration because of IVDE may experience complications during the intraoperative, immediate postoperative, and late postoperative periods. However, these complications are often transitory and rarely cause death.

A hemilaminectomia e a fenestração do disco intervertebral são os procedimentos cirúrgicos geralmente empregados no tratamento da extrusão do disco intervertebral (EDIV), os quais podem desencadear complicações cirúrgicas. Foram avaliadas complicações em 64 cães nos períodos intra e pós-operatório imediato e tardio. Dos pacientes incluídos no estudo, 15,62% (n=10) apresentaram alguma ocorrência em pelo menos uma das etapas avaliadas. Das complicações, no período intraoperatório foram observadas rizotomia iatrogênica, abertura do canal vertebral contralateral e parada cardio-respiratória. No pós-operatório imediato foram verificadas a flacidez da parede abdominal lateral, piora neurológica, hematoma, deiscência de ferida cirúrgica e infecção superficial da ferida de pele. No pós-operatório tardio foram verificadas reação ao fio cirúrgico, aderência cicatricial e flacidez da parede abdominal lateral como problemas mais frequentes. Conclui-se que cães submetidos à hemilaminectomia e fenestração do disco intervertebral envolvido em decorrência da EDIV podem apresentar complicações nos períodos intraoperatório, pós-operatório imediato e tardio, sendo transitórias e com mínimas chances de ocasionar óbito.

Analgesia pós-operatória com Fentanil transdérmico ou Metadona intramuscular em cães submetidos à hemilaminectomia toracolombar / Postoperative analgesia with transdermal Fentanyl or intramuscular Methadone in dogs submitted to thoracolumbar hemilaminectomy

Background: Postoperative care after thoracolumbar hemilaminectomy in dogs generally includes rest, physical therapy,and analgesics such as opioids. Currently, there is no established standard for the management of postoperative pain inpatients undergoing hemilaminectomy. Ideally, an analgesic protocol should provide adequate pain relief with limited sedation, low adverse effects, and postoperative patient comfort. Therefore, this study aimed to evaluate postoperative analgesiausing transdermal fentanyl or intramuscular methadone in dogs undergoing thoracolumbar hemilaminectomy associatedwith intervertebral disc fenestration (HT) for the treatment of intervertebral disc extrusion (IVDE).Materials, Methods & Results: Eight dogs from the Department of Neurology and Neurosurgery of a Veterinary TeachingHospital, submitted to HT for the treatment of IVDE, were included. The dogs were randomly distributed into 2 groups ofequal numbers, namely the transdermal fentanyl (FT) group and the intramuscular methadone (IM) group. At the end ofthe surgical procedure, a fentanyl adhesive patch was applied to the animals in the FT group, which remained there for 72h. In the IM group, analgesia was induced by intramuscular administration of methadone at intervals of 6 h until 72 h aftersurgery. The animals were evaluated using the short form of the Glasgow Composite Measure Pains Scale (CMPS-SF).Evaluations of physiological parameters, side effects, and pain were performed by 2 assessors who had experience usingthe pain scale and were blinded to the analgesic protocol. Pain evaluations were performed every 2 h (from T4) until 24h after the surgical procedure. Evaluations were performed every 4 h from 24 h to 48 h after the surgical procedure and...

Focal spinal hyperesthesia as a prognostic factor in paraplegic dogs without deep pain perception / Hiperestesia espinhal focal como fator prognóstico em cães paraplégicos sem percepção de dor profunda

Intervertebral disc extrusion (IVDE) is the most common cause of spinal cord compression in dogs, whose prognosis is variable and depends on several factors, with deep pain perception (DPP) being the main parameter used. Investigations of new prognostic factors are studied to assist in the estimation of functional recovery. Thus, this study aimed to evaluate whether spinal hyperesthesia (SH) at the compression site can be used as a prognostic factor for the functional recovery of dogs with acute IVDE (Hansen type I), without DPP being subjected to thoracolumbar hemilaminectomy. Decompression surgery was performed on the same day or the day after admission. The duration of the loss of DPP until surgery performance ranged from 1 to 60 days, with a median of 4.5 days for the group of dogs with SH and 5.5 days for those without SH. Among the 68 dogs included in this retrospective study, 73.5% (50/68) showed SH, and 26.5% (18/68) were not identified. Recovery was satisfactory in 60% (30/50) of dogs with SH and in 27.7% (5/18) of dogs without SH, demonstrating that paraplegic dogs without DPP but with SH were 3.9 times more likely to recover when compared to dogs in the same condition, but with no SH. No studies have evaluated SH by palpation of the spine as a prognostic factor, which reinforces the relevance of the present study. The results of this study imply that SH in paraplegic dogs affected by thoracolumbar IVDE, without the presence of DPP, can be used as a possible prognostic indicator of functional recovery.

A extrusão do disco intervertebral (EDIV) é a causa mais comum de lesão compressiva na medula espinhal de cães, cujo prognóstico é variável e depende de diversos fatores, sendo a percepção de dor profunda (PDP) o principal parâmetro utilizado. Pesquisas de novos fatores prognósticos são estudados com intuito de auxiliar na estimativa mais precisa de recuperação funcional. Com isso, o objetivo do estudo foi avaliar se a hiperestesia espinhal (HE) no local da compressão, pode ser utilizada como um fator prognóstico para recuperação funcional de cães com extrusão aguda do disco intervertebral (Hansen tipo I), sem a presença de PDP submetidos a hemilaminectomia toracolombar. A cirurgia descompressiva ocorreu no mesmo dia ou no dia seguinte ao atendimento. A duração da perda de dor profunda até a realização da cirurgia variou de 1 a 60 dias, com uma mediana de 4,5 dias para o grupo de cães com e 5,5 dias para aqueles sem hiperestesia espinhal. Dos 68 cães incluídos nesse estudo retrospectivo, 73,5% (50/68) apresentavam HE e, em 26,5% (18/68) a dor não foi identificada. A recuperação foi satisfatória nos cães com HE em 60% (30/50) e, sem HE, em 27,7% (5/18) dos casos, demonstrando que os cães paraplégicos sem PDP, mas com presença de hiperestesia espinhal tem 3,9 vezes mais chances de recuperação quando comparado com cães na mesma condição, mas sem HE. Não foram encontrados trabalhos que avaliaram a HE mediante a palpação da coluna vertebral como um fator prognóstico, o que reforça a relevância do presente estudo. Os resultados do presente trabalho sugerem que a HE em cães paraplégicos acometidos por EDIV toracolombar sem presença de PDP pode ser utilizada como um possível indicador prognóstico de recuperação funcional.

The need for opioid in the postoperative analgesia of dogs undergoing hemilaminectomy due to intervertebral disc extrusion

ABSTRACT: The aim of this study was to evaluate the postoperative analgesic effect of protocols with and without the opioid methadone in dogs with intervertebral disc extrusion undergoing decompressive surgery. Sixteen paraplegic dogs with preserved nociception underwent hemilaminectomy/disc fenestration and were randomly assigned to two groups. The analgesic protocol consisted of methadone, meloxicam and dipyrone in Group I (G1), and meloxicam and dipyrone in Group II (G2). The animals were blindly assessed by two observers, using the visual analogue scale (VAS) and the short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Assessments occurred every 2 hours during first 24 hours post-surgery, and every 4 hours afterwards. There was no statistical difference among groups regarding pain scores or analgesic rescues. Both analgesic protocols provided analgesia in the initial 48 hours postoperatively, demonstrating that opioids are not necessary in the postoperative period of dogs undergoing hemilaminectomy and disc fenestration.

RESUMO: O objetivo deste estudo foi avaliar a analgesia pós-operatória de protocolos com e sem o opioide metadona em cães com extrusão de disco intervertebral submetidos à descompressão cirúrgica. Dezesseis cães paraplégicos com presença de nocicepção foram submetidos à hemilaminectomia/fenestração de disco e distribuídos aleatoriamente em dois grupos. No Grupo I (G1), o protocolo analgésico consistiu em metadona, meloxicam e dipirona e, no Grupo II (G2), por meloxicam e dipirona. Os pacientes foram avaliados de maneira cega por dois avaliadores, com base na escala visual analógica (EVA) e na escala simplificada composta de dor de Glasgow (CMPS-SF). As avaliações ocorreram a cada 2 horas durante as primeiras 24 horas de pós-operatório e, por mais 24 horas, a cada 4 horas. Não houve diferença estatística entre os grupos avaliados em relação à escores de dor e nem a necessidade de resgate analgésico. Ambos os protocolos promoveram analgesia nas 48 horas iniciais de pós-operatório, demonstrando não haver a necessidade do uso de opioide em cães submetidos à hemilaminectomia e fenestração de disco.

The need for opioid in the postoperative analgesia of dogs undergoing hemilaminectomy due to intervertebral disc extrusion / A necessidade de opioide na analgesia pós-operatória de cães submetidos à hemilaminectomia devido à extrusão do disco intervertebral

The aim of this study was to evaluate the postoperative analgesic effect of protocols with and without the opioid methadone in dogs with intervertebral disc extrusion undergoing decompressive surgery. Sixteen paraplegic dogs with preserved nociception underwent hemilaminectomy/disc fenestration and were randomly assigned to two groups. The analgesic protocol consisted of methadone, meloxicam and dipyrone in Group I (G1), and meloxicam and dipyrone in Group II (G2). The animals were blindly assessed by two observers, using the visual analogue scale (VAS) and the short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Assessments occurred every 2 hours during first 24 hours post-surgery, and every 4 hours afterwards. There was no statistical difference among groups regarding pain scores or analgesic rescues. Both analgesic protocols provided analgesia in the initial 48 hours postoperatively, demonstrating that opioids are not necessary in the postoperative period of dogs undergoing hemilaminectomy and disc fenestration.(AU)

O objetivo deste estudo foi avaliar a analgesia pós-operatória de protocolos com e sem o opioide metadona em cães com extrusão de disco intervertebral submetidos à descompressão cirúrgica. Dezesseis cães paraplégicos com presença de nocicepção foram submetidos à hemilaminectomia/fenestração de disco e distribuídos aleatoriamente em dois grupos. No Grupo I (G1), o protocolo analgésico consistiu em metadona, meloxicam e dipirona e, no Grupo II (G2), por meloxicam e dipirona. Os pacientes foram avaliados de maneira cega por dois avaliadores, com base na escala visual analógica (EVA) e na escala simplificada composta de dor de Glasgow (CMPS-SF). As avaliações ocorreram a cada 2 horas durante as primeiras 24 horas de pós-operatório e, por mais 24 horas, a cada 4 horas. Não houve diferença estatística entre os grupos avaliados em relação à escores de dor e nem a necessidade de resgate analgésico. Ambos os protocolos promoveram analgesia nas 48 horas iniciais de pós-operatório, demonstrando não haver a necessidade do uso de opioide em cães submetidos à hemilaminectomia e fenestração de disco.(AU)

The need for opioid in the postoperative analgesia of dogs undergoing hemilaminectomy due to intervertebral disc extrusion / A necessidade de opioide na analgesia pós-operatória de cães submetidos à hemilaminectomia devido à extrusão do disco intervertebral

The aim of this study was to evaluate the postoperative analgesic effect of protocols with and without the opioid methadone in dogs with intervertebral disc extrusion undergoing decompressive surgery. Sixteen paraplegic dogs with preserved nociception underwent hemilaminectomy/disc fenestration and were randomly assigned to two groups. The analgesic protocol consisted of methadone, meloxicam and dipyrone in Group I (G1), and meloxicam and dipyrone in Group II (G2). The animals were blindly assessed by two observers, using the visual analogue scale (VAS) and the short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Assessments occurred every 2 hours during first 24 hours post-surgery, and every 4 hours afterwards. There was no statistical difference among groups regarding pain scores or analgesic rescues. Both analgesic protocols provided analgesia in the initial 48 hours postoperatively, demonstrating that opioids are not necessary in the postoperative period of dogs undergoing hemilaminectomy and disc fenestration.(AU)

O objetivo deste estudo foi avaliar a analgesia pós-operatória de protocolos com e sem o opioide metadona em cães com extrusão de disco intervertebral submetidos à descompressão cirúrgica. Dezesseis cães paraplégicos com presença de nocicepção foram submetidos à hemilaminectomia/fenestração de disco e distribuídos aleatoriamente em dois grupos. No Grupo I (G1), o protocolo analgésico consistiu em metadona, meloxicam e dipirona e, no Grupo II (G2), por meloxicam e dipirona. Os pacientes foram avaliados de maneira cega por dois avaliadores, com base na escala visual analógica (EVA) e na escala simplificada composta de dor de Glasgow (CMPS-SF). As avaliações ocorreram a cada 2 horas durante as primeiras 24 horas de pós-operatório e, por mais 24 horas, a cada 4 horas. Não houve diferença estatística entre os grupos avaliados em relação à escores de dor e nem a necessidade de resgate analgésico. Ambos os protocolos promoveram analgesia nas 48 horas iniciais de pós-operatório, demonstrando não haver a necessidade do uso de opioide em cães submetidos à hemilaminectomia e fenestração de disco.(AU)

A new anesthetic protocol to medullary nerve roots access in rats

ABSTRACT Purpose: 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.

Anestesia multimodal em cachorro-do-mato (Cerdocyon thous) submetido à hemilaminectomia e estabilização sacrococcígea / Multimodal anaesthesia in a crab-eating fox (Cerdocyon thous) undergoing hemilaminectomy and sacrococcygeal stabilization

Background: Several researches have shown the impacts of roads more directly to wildlife in Brazil. The crab-eating fox(Cerdocyon thous) is a frequent run over victim. Dissociative drugs are commonly used, but inhalation anesthesia is indicatedin cases of extensive and prolonged surgeries. Despite their similarity with domestic dogs, the literature is scarce regarding theassociation of new anesthetic techniques and protocols in wild canids. The aim of this paper was to report the viability of multimodal anesthesia in a crab-eating fox, victim of running over, undergoing hemilaminectomy and sacrococcygeal stabilization.Case: An adult male specimen of crab-eating fox was rescued after being run over and taken to a wild animal screening center.Physical examination showed superficial and deep pain, lack of support for the pelvic limbs and proprioception, increasedreflexes, and reduced tail mobility. Chemical restraint with intramuscular (IM) tiletamine-zolazepam (6.0 mg/kg) and morphine (0.5 mg/kg) was performed. Meloxicam (0.2 mg/kg IM) and enrofloxacin (5.0 mg/kg IM) were also administered. Theanimal was sequentially admitted to the veterinary hospital. Radiographic images showed compaction of the spinal columnof the T10 and T11 thoracic vertebrae and the sacrococcygeal region. Sixty min after chemical restraint, the anesthesia wassupplemented with IM tiletamine-zolazepam (4.5 mg/kg), and fluid therapy with 0.9% NaCl (10 mL/kg/h) was started. Ten minlater, intravenous propofol dose-effect (2.5 mg/kg) was administered and general anesthesia was maintained with isoflurane(FiO2 = 1.0). Thirty min after the induction of anesthesia, the animal was urdergoing hemilaminectomy and sacrococcygealstabilization. Constant rate infusions (CRI) of dexmedetomidine (0.5 μg/kg/h) and ketamine (0.6 mg/kg/h) were started. Lidocaine (7.0 mg/kg) and bupivacaine (2.0 mg/kg) were administered into the surgical site on the T10 and T11 vertebrae at 35...(AU)

Anestesia multimodal em cachorro-do-mato (Cerdocyon thous) submetido à hemilaminectomia e estabilização sacrococcígea / Multimodal anaesthesia in a crab-eating fox (Cerdocyon thous) undergoing hemilaminectomy and sacrococcygeal stabilization

Background: Several researches have shown the impacts of roads more directly to wildlife in Brazil. The crab-eating fox(Cerdocyon thous) is a frequent run over victim. Dissociative drugs are commonly used, but inhalation anesthesia is indicatedin cases of extensive and prolonged surgeries. Despite their similarity with domestic dogs, the literature is scarce regarding theassociation of new anesthetic techniques and protocols in wild canids. The aim of this paper was to report the viability of multimodal anesthesia in a crab-eating fox, victim of running over, undergoing hemilaminectomy and sacrococcygeal stabilization.Case: An adult male specimen of crab-eating fox was rescued after being run over and taken to a wild animal screening center.Physical examination showed superficial and deep pain, lack of support for the pelvic limbs and proprioception, increasedreflexes, and reduced tail mobility. Chemical restraint with intramuscular (IM) tiletamine-zolazepam (6.0 mg/kg) and morphine (0.5 mg/kg) was performed. Meloxicam (0.2 mg/kg IM) and enrofloxacin (5.0 mg/kg IM) were also administered. Theanimal was sequentially admitted to the veterinary hospital. Radiographic images showed compaction of the spinal columnof the T10 and T11 thoracic vertebrae and the sacrococcygeal region. Sixty min after chemical restraint, the anesthesia wassupplemented with IM tiletamine-zolazepam (4.5 mg/kg), and fluid therapy with 0.9% NaCl (10 mL/kg/h) was started. Ten minlater, intravenous propofol dose-effect (2.5 mg/kg) was administered and general anesthesia was maintained with isoflurane(FiO2 = 1.0). Thirty min after the induction of anesthesia, the animal was urdergoing hemilaminectomy and sacrococcygealstabilization. Constant rate infusions (CRI) of dexmedetomidine (0.5 μg/kg/h) and ketamine (0.6 mg/kg/h) were started. Lidocaine (7.0 mg/kg) and bupivacaine (2.0 mg/kg) were administered into the surgical site on the T10 and T11 vertebrae at 35...

Extrusão de disco intervertebral intradural em um cão / Intradural disc extrusion in a dog

Background: Intervertebral disc extrusion is an important cause of spinal cord dysfunction in dogs. Intradural localizationof the extruded disc material is rare, and is generally associated with a traumatic event or with recurrence of disc extrusionat a previously affected site. We report the clinical presentation, diagnostic workup, and treatment of a dog with intraduralintervertebral disc extrusion not preceded by a traumatic event.Case: A 6-year-old male Dachshund was referred for neurological evaluation due to acute onset of hind-end paralysispreceded by claudication of the left hindlimb. The patient had been receiving conservative treatment to no effect. Neurological examination revealed asymmetric non-ambulatory paraparesis, absence of postural reactions and decreased muscletone in both hindlimbs, a bilaterally diminished patellar reflex, and a hindlimb withdrawal reflex which was normal onthe right and greatly diminished to absent on the left. The lower back was tender to epaxial palpation. Plain radiographsof the lumbar spine in the lateral projection showed calcified material within the spinal canal between the third and fourthlumbar vertebrae. Myelography was suggestively abnormal at the same level, with epidural leakage of contrast at L3-L4.Considering the clinical history, breed, age, neurological signs, and radiographic findings, intervertebral disc disease wassuspected despite the inconclusive myelography findings. A dorsolateral lumbar hemilaminectomy was performed. Intraoperatively, the diagnosis was confirmed by visualization of a discolored spinal cord and absence of extradural material.The intradural space was accessed via durotomy. A firm, straw-yellow material was seen compressing the spinal cord andremoved. Subsequent histopathological...

Extrusão de disco intervertebral intradural em um cão / Intradural disc extrusion in a dog

Background: Intervertebral disc extrusion is an important cause of spinal cord dysfunction in dogs. Intradural localizationof the extruded disc material is rare, and is generally associated with a traumatic event or with recurrence of disc extrusionat a previously affected site. We report the clinical presentation, diagnostic workup, and treatment of a dog with intraduralintervertebral disc extrusion not preceded by a traumatic event.Case: A 6-year-old male Dachshund was referred for neurological evaluation due to acute onset of hind-end paralysispreceded by claudication of the left hindlimb. The patient had been receiving conservative treatment to no effect. Neurological examination revealed asymmetric non-ambulatory paraparesis, absence of postural reactions and decreased muscletone in both hindlimbs, a bilaterally diminished patellar reflex, and a hindlimb withdrawal reflex which was normal onthe right and greatly diminished to absent on the left. The lower back was tender to epaxial palpation. Plain radiographsof the lumbar spine in the lateral projection showed calcified material within the spinal canal between the third and fourthlumbar vertebrae. Myelography was suggestively abnormal at the same level, with epidural leakage of contrast at L3-L4.Considering the clinical history, breed, age, neurological signs, and radiographic findings, intervertebral disc disease wassuspected despite the inconclusive myelography findings. A dorsolateral lumbar hemilaminectomy was performed. Intraoperatively, the diagnosis was confirmed by visualization of a discolored spinal cord and absence of extradural material.The intradural space was accessed via durotomy. A firm, straw-yellow material was seen compressing the spinal cord andremoved. Subsequent histopathological...(AU)

Pediculectomy and fenestration for spinal cord decompression of the lumbar spine of a bush dog (Speothos venaticus) - case report / [Pediculectomia e fenestração para descompressão medular da coluna lombar em um cachorro-vinagre (Speothos venaticus) - relato de caso]

A captive adult male bush dog (Speothos venaticus) was referred to our Veterinary Medical Teaching Hospital from a local zoo due to a two-week history of progressive hind limb gait impairment and ataxia, non-responsive to clinical management. Computed tomography revealed decreased disc space at L3 - L4 level, with probable disc extrusion narrowing the right side of the spinal canal, compressing the spinal cord. We opted to surgically remove the disc material using both fenestration and right lateral pediculectomy (mini-hemilaminectomy) techniques. Twelve days after surgery there was mild residual proprioceptive ataxia. Gait was fully regained with remission of the neurological deficits around the 30th postoperative day. This is - to the best of our knowledge - the first successful report of a lumbar intervertebral disc extrusion in a bush dog (Speothos venaticus) surgically treated by pediculectomy and disc fenestration.(AU)

Um cachorro-vinagre (Speothos venaticus), macho, adulto, mantido em cativeiro, foi encaminhado ao Hospital Veterinário Universitário pelo zoológico local com histórico de duas semanas de comprometimento progressivo da marcha dos membros posteriores e ataxia, que não responderam ao tratamento clínico. Tomografia computadorizada revelou diminuição do espaço em disco no nível L3 - L4, com provável extrusão de disco estreitando o lado direito do canal vertebral, comprimindo a medula espinhal. Optamos por remover cirurgicamente esse material do disco usando técnicas de fenestração e pediculectomia lateral direita (mini-hemilaminectomia). Doze dias após a cirurgia, houve melhora na deambulação, com ataxia proprioceptiva residual leve. A marcha foi totalmente recuperada com remissão dos déficits neurológicos por volta do trigésimo dia de pós-operatório. Este é - até onde sabemos - o primeiro relato bem-sucedido de uma extrusão de disco intervertebral lombar em um cachorro-vinagre (Speothos venaticus) tratado cirurgicamente por pediculectomia e fenestração de disco.(AU)

Laminotomia dorsal do áxis para excisão de meningioma em cão / Axis dorsal laminotomy for excision of a meningioma in a dog

Background: Surgical access to the spinal cord at the level of C2 vertebra presents technical limitations, due to anatomical particularities in this region. The ventral slot technique does not allow space for the removal of dorsolateral masses. The axis hemilaminectomy technique provides limited access to the dorsal aspect of spinal cord and there is a risk of damaging the vertebral arteries. The axis dorsal laminotomy technique allows good access to spinal cord and preserves the atlantoaxial and nuchal ligaments, however few papers describe this technique. The objective of this paper is to report the axis dorsal laminotomy performed in a dog with a meningioma at this level. Case: An 11-year-old male, Maltese dog, was presented with a 15-day history of progressive weakness, intense cervical pain and difficulty in locomotion of the four limbs. He was being treated with painkillers without improvement. On clinical examination, the physiological parameters were normal. Neurological examination showed tetraparesis with the syndrome localized in the cranial cervical region. The main differential diagnoses were intervertebral disc disease, neoplasia, inflammatory or infectious disease. Computed tomography was performed and the evaluation of images allowed the visualization of an intradural-extramedullary neoplastic process, promoting important spinal compression, with approximate dimensions of the lesion 0.70 cm high x 0.67 cm wide x 0.78 cm long, with apparent involvement of the meninges, with a more lateralized location on the left, with meningioma being the main differential diagnosis. Thus, exploratory surgery, through the technique of dorsal laminotomy of the axis was performed. After the removal of the mass, the spinous process was repositioned in its anatomical location and fixed with 0.6 mm steel cerclage wire that was passed through the holes made in the dorsal lamina of the...

Laminotomia dorsal do áxis para excisão de meningioma em cão / Axis dorsal laminotomy for excision of a meningioma in a dog

Background: Surgical access to the spinal cord at the level of C2 vertebra presents technical limitations, due to anatomical particularities in this region. The ventral slot technique does not allow space for the removal of dorsolateral masses. The axis hemilaminectomy technique provides limited access to the dorsal aspect of spinal cord and there is a risk of damaging the vertebral arteries. The axis dorsal laminotomy technique allows good access to spinal cord and preserves the atlantoaxial and nuchal ligaments, however few papers describe this technique. The objective of this paper is to report the axis dorsal laminotomy performed in a dog with a meningioma at this level. Case: An 11-year-old male, Maltese dog, was presented with a 15-day history of progressive weakness, intense cervical pain and difficulty in locomotion of the four limbs. He was being treated with painkillers without improvement. On clinical examination, the physiological parameters were normal. Neurological examination showed tetraparesis with the syndrome localized in the cranial cervical region. The main differential diagnoses were intervertebral disc disease, neoplasia, inflammatory or infectious disease. Computed tomography was performed and the evaluation of images allowed the visualization of an intradural-extramedullary neoplastic process, promoting important spinal compression, with approximate dimensions of the lesion 0.70 cm high x 0.67 cm wide x 0.78 cm long, with apparent involvement of the meninges, with a more lateralized location on the left, with meningioma being the main differential diagnosis. Thus, exploratory surgery, through the technique of dorsal laminotomy of the axis was performed. After the removal of the mass, the spinous process was repositioned in its anatomical location and fixed with 0.6 mm steel cerclage wire that was passed through the holes made in the dorsal lamina of the...(AU)

Pediculectomy and fenestration for spinal cord decompression of the lumbar spine of a bush dog (Speothos venaticus) - case report / [Pediculectomia e fenestração para descompressão medular da coluna lombar em um cachorro-vinagre (Speothos venaticus) - relato de caso]

A captive adult male bush dog (Speothos venaticus) was referred to our Veterinary Medical Teaching Hospital from a local zoo due to a two-week history of progressive hind limb gait impairment and ataxia, non-responsive to clinical management. Computed tomography revealed decreased disc space at L3 - L4 level, with probable disc extrusion narrowing the right side of the spinal canal, compressing the spinal cord. We opted to surgically remove the disc material using both fenestration and right lateral pediculectomy (mini-hemilaminectomy) techniques. Twelve days after surgery there was mild residual proprioceptive ataxia. Gait was fully regained with remission of the neurological deficits around the 30th postoperative day. This is - to the best of our knowledge - the first successful report of a lumbar intervertebral disc extrusion in a bush dog (Speothos venaticus) surgically treated by pediculectomy and disc fenestration.(AU)

Um cachorro-vinagre (Speothos venaticus), macho, adulto, mantido em cativeiro, foi encaminhado ao Hospital Veterinário Universitário pelo zoológico local com histórico de duas semanas de comprometimento progressivo da marcha dos membros posteriores e ataxia, que não responderam ao tratamento clínico. Tomografia computadorizada revelou diminuição do espaço em disco no nível L3 - L4, com provável extrusão de disco estreitando o lado direito do canal vertebral, comprimindo a medula espinhal. Optamos por remover cirurgicamente esse material do disco usando técnicas de fenestração e pediculectomia lateral direita (mini-hemilaminectomia). Doze dias após a cirurgia, houve melhora na deambulação, com ataxia proprioceptiva residual leve. A marcha foi totalmente recuperada com remissão dos déficits neurológicos por volta do trigésimo dia de pós-operatório. Este é - até onde sabemos - o primeiro relato bem-sucedido de uma extrusão de disco intervertebral lombar em um cachorro-vinagre (Speothos venaticus) tratado cirurgicamente por pediculectomia e fenestração de disco.(AU)

Neoplasia do plexo braquial com infiltração medular / Brachial plexus neoplasia with spinal cord infiltration: report case

Tumores originados no sistema nervoso periférico não são comuns na clínica veterinária e seu diagnóstico é difícil. Por ser uma patologia de curso lento e insidioso muitos profissionais demoram a suspeitar dos tumores de plexo braquial, retardando muito o diagnóstico e tratamento. Os sinais clínicos observados são claudicação, dor à palpação axilar,monoparesia e, em casos mais graves, com infiltração neoplásica na medula espinhal, o paciente pode apresentar tetraparesia. Foi atendida uma cadela fox paulistinha com 10 anos de idade apresentando tetraparesia não ambulatória. O exame clínico foi sugestivo de uma lesão de medula espinhal (C6-T2), suspeitando-se de doença do disco intervertebral ou neoplasia medular. A mielografia foi realizada e mostrou compressão caudal a C6. O animal foi então submetido àhemilaminectomia para descompressão, sendo observada infiltração neoplásica das raízes nervosas na medula espinhal impossível de ser resseccionada. O paciente foi eutanasiado. O plexo braquial, os nervos espinhais e a medula foram colhidos e enviados para examehistopatológico, confirmando-se o diagnóstico de tumor maligno de bainhade nervo periférico (TMNP). O presente relato mostrou um caso cujo curso clínico da doença foi atípico, dificultando o diagnóstico. Conclui-se que sempre se deve considerar a possibilidade de neoplasias de plexo braquial em pacientes com histórico de claudicação crônica de membros torácicos não responsiva a repouso e anti-inflamatórios.

Primary tumour of peripheral nerves are not common in veterinary practice and its diagnosis is difficult. Being a condition of slow and insidious course many professionals are slow to suspect the brachial plexus tumors, delaying diagnosis and treatment. The clinical signs observed in this disease are lameness, pain axillary palpation, monoparesis and in severe cases with neoplastic infiltration in the spinalcord, the patient may experience tertraparesia. A female dog Fox Paulistinha with 10-year-old was met with tetraparesia not ambulatory. Clinical examination was suggestive of a spinal cord injury (C6-T2),suspected presence of disc herniation and spinal cord cancer. The myelography was performed and showed compressive C6 flow. The animal was then subjected to a decompression Hemilaminectomy being observed neoplastic infiltration of the nerve roots in the spinal cord impossible to beresected. The patient was euthanized, the brachial plexus, the spinal nerves and the affected spinal cord were collected and sent for histopathological examination, confirming the diagnosis of malignantperipheral nerve sheath tumor (MPNST) in the brachial plexus. This report shows a brachial plexus tumors case whose clinical course of the disease was atypical making diagnosis difficult. The conclusion is that youshould always consider the brachial plexus tumors in patients with a history of chronic lameness forelimbs unresponsive to rest and anti-inflammatory.

Neoplasia do plexo braquial com infiltração medular / Brachial plexus neoplasia with spinal cord infiltration: report case

Tumores originados no sistema nervoso periférico não são comuns na clínica veterinária e seu diagnóstico é difícil. Por ser uma patologia de curso lento e insidioso muitos profissionais demoram a suspeitar dos tumores de plexo braquial, retardando muito o diagnóstico e tratamento. Os sinais clínicos observados são claudicação, dor à palpação axilar,monoparesia e, em casos mais graves, com infiltração neoplásica na medula espinhal, o paciente pode apresentar tetraparesia. Foi atendida uma cadela fox paulistinha com 10 anos de idade apresentando tetraparesia não ambulatória. O exame clínico foi sugestivo de uma lesão de medula espinhal (C6-T2), suspeitando-se de doença do disco intervertebral ou neoplasia medular. A mielografia foi realizada e mostrou compressão caudal a C6. O animal foi então submetido àhemilaminectomia para descompressão, sendo observada infiltração neoplásica das raízes nervosas na medula espinhal impossível de ser resseccionada. O paciente foi eutanasiado. O plexo braquial, os nervos espinhais e a medula foram colhidos e enviados para examehistopatológico, confirmando-se o diagnóstico de tumor maligno de bainhade nervo periférico (TMNP). O presente relato mostrou um caso cujo curso clínico da doença foi atípico, dificultando o diagnóstico. Conclui-se que sempre se deve considerar a possibilidade de neoplasias de plexo braquial em pacientes com histórico de claudicação crônica de membros torácicos não responsiva a repouso e anti-inflamatórios.(AU)

Primary tumour of peripheral nerves are not common in veterinary practice and its diagnosis is difficult. Being a condition of slow and insidious course many professionals are slow to suspect the brachial plexus tumors, delaying diagnosis and treatment. The clinical signs observed in this disease are lameness, pain axillary palpation, monoparesis and in severe cases with neoplastic infiltration in the spinalcord, the patient may experience tertraparesia. A female dog Fox Paulistinha with 10-year-old was met with tetraparesia not ambulatory. Clinical examination was suggestive of a spinal cord injury (C6-T2),suspected presence of disc herniation and spinal cord cancer. The myelography was performed and showed compressive C6 flow. The animal was then subjected to a decompression Hemilaminectomy being observed neoplastic infiltration of the nerve roots in the spinal cord impossible to beresected. The patient was euthanized, the brachial plexus, the spinal nerves and the affected spinal cord were collected and sent for histopathological examination, confirming the diagnosis of malignantperipheral nerve sheath tumor (MPNST) in the brachial plexus. This report shows a brachial plexus tumors case whose clinical course of the disease was atypical making diagnosis difficult. The conclusion is that youshould always consider the brachial plexus tumors in patients with a history of chronic lameness forelimbs unresponsive to rest and anti-inflammatory.(AU)