A musculatura epaxial e a fibrose epidural na compressão medular em cães submetidos à laminectomia dorsal modificada

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 (PThe 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.