A musculatura epaxial e a fibrose epidural na compressão medular em cães submetidos à laminectomia dorsal modificada / Epaxial musculature and epidural fibrosis in the spinal compression in dogs submitted modified dorsal laminectomy

O objetivo deste experimento foi isolar a musculatura epaxial da medula espinhal de cães submetidos à laminectomia dorsal modificada (LDM) e averiguar se os músculos influenciaram na formação da fibrose epidural, na compressão medular e no aparecimento dos sinais neurológicos. Para isso, dez cães hígidos foram submetidos à LDM entre as vértebras T13 e L1 e distribuídos aleatoriamente em dois grupos denominados controle (I) onde a medula espinhal permaneceu exposta sem a presença de implante, e tratado (II)onde foi colocado um im-plante a base de alumínio entre a musculatura epaxial adjacente e a medula espinhal exposta pela LDM. As avaliações constaram de exames neurológicos diários até 180 dias de pós-operatório (PO); mielografia, decorridos 15, 30 e 60 dias de PO; e avaliação macroscópica mediante a reintervenção cirúrgica. Não houve diferença durante as avaliações neurológicas. Aos 15 dias de PO, foi verificado na mielografia, que o grau de compressão da linha de contraste foi maior no grupo tratado (P<0,05) quando comparado ao grupo controle, não havendo diferença dos demais tempos estudados. Na avaliação macroscópica, pode-se observar que no Grupo II, a musculatura epaxial adjacente à medula espinhal não estava em contato com a fibrose epidural, diferentemente do grupo controle. O implante pôde ser removido facilmente e apresentava discreto grau de deformidade crânio-dorsal. Pode-se concluir que a musculatura epaxial adjacente é isolada da medula espinhal pelo implante à base de alumínio em cães submetidos à LDM, e esta não influencia na formação da fibrose epidural, compressão medular e no aparecimento dos sinais neurológicos.

The purpose of this study was to isolate the adjacent epaxial musculature from exposed spinal cord by modified dorsal laminectomy in dogs with aluminum implant and to verify whether the muscles contribute to form epidural fibrosis, spinal cord compression, and development of neurological signs. Ten dogs were submitted to modified dorsal laminectomy between T13 and L1 and then distributed along two groups. Dogs in the group 1 remained with the spinal cord exposed without the implant; dogs in the group 2 had an aluminum implant inserted between the epaxial muscles and the exposed spinal cord. Neurological examination was daily performed until 180 days post surgery. Additionally, myelography at 15, 30, and 60 days post surgery and macroscopic evaluation of the implant at six months post surgery were done. There was no difference between groups in the neurological examination. A statistical difference in the degree of spinal compression was observed at day 15 post surgery in the group 2. In this group, the epaxial musculature adjacent to the spinal cord was not in contact with the epidural fibrosis, differently to what was observed in the control group. The implant was removed easily with some degree of deformity. The results showed that the adjacent musculature of the spinal cord submitted to a modified dorsal laminectomy in dogs can be isolated by aluminum implant, without any contact with epidural fibrosis or influence in the development of neurological signs.

Lipomatose epidural lombar: relato de dois casos / Lumbar epidural lipomatosis: report of two cases

Objetivo: descrever e relatar uma patologia relativamente rara, que deve ser sugerida no diagnóstico diferencial das lombalgias e síndromes radicuylares lombossacrais. Método: análise e descrição de dois casos de lipomatose epidural lombar operados no Serviço de Neurocirurgia da Santa casa de Santos pelos autores no período de três anos. Resultados: os pacientes operados evoluíram com melhora dos sintomas realcionados à lipomatose epidural lombar. Conclusão: a lo]ipomatose epidural deve sempre ser incluída no diagnóstico diferencial diante de queixa de lombalgia e ciática, ou ainda compressão medular dorsal. Obesidade e uso de corticóides devem ser considerados como sinais de suspeita para tal patologia, que, quando correta e rapidamente descoberta e tratada, pode evitar graves consequências para o doente.

Establishment of a canine spinal cord injury model induced by epidural balloon compression

A model that provides reproducible, submaximal yet sufficient spinal cord injury is needed to allow experiments leading to development of therapeutic techniques and prediction of clinical outcome to be conducted. This study describes an experimental model for spinal cord injury that uses three different volumes of balloon inflation and durations of compression to create a controlled gradation outcome in adult dogs. Twenty-seven mongrel dogs were used for this study. A 3-french embolectomy catheter was inserted into the epidural space through a left hemilaminectomy hole at the L4 vertebral arch. Balloons were then inflated with 50, 100, or 150 microliter of a contrast agent at the L1 level for 6, 12, or 24 h and spinal canal occlusion (SCO) measured using computed tomography. Olby score was used to evaluate the extent of spinal cord injury and a histopathologic examination was conducted 1 week after surgery. The SCO of the 50, 100, and 150 microliter inflations was 22-46%, 51-70%, and 75-89%, respectively (p 50% for 24 h, and > 75% for 12 h induces paraplegia up to a week after spinal cord injury.