Anatomia do cone medular aplicada à via epidural de administração de fármacos em macacos-prego ( Sapajus libidinosus )

Abstract

RESUMO.-Com este estudo objetivou-se descrever a topografia do cone medular do macaco-prego (Sapajus libidinosus) a fim de fornecer suporte para que a realização de procedimentos anestésicos, bem como exames de mielografia e coleta de líquor, dentre outros procedimentos que utilizam a via epidural. Para tanto foram dissecados oito animais, sendo seis machos e duas fêmeas, de diferentes faixas etárias. Rebateu-se a pele para retirada da musculatura da região dorsal, exposição de toda a coluna vertebral e identificação das vértebras lombares e sacrais. Para estabelecer o final da medula espinhal e medir o comprimento This study aimed to describe the topography of the conus of capuchin monkey (Sapajus libidinosus) to provide support for anesthetic procedures, as well as examinations of myelography and CSF collection, among other procedures using the epidural route. Eight animals were dissected, six males and two females, of different ages. The skin was countered for removal of the dorsal musculature for exposure of the entire spine and identification of the lumbar and sacral vertebrae. To establish the end of the spinal cord and to measure the length of the conus medullaris, we opened the lumbosacral spinal canal through side section of the vertebral arches. The dura mater was sectioned to visualize the conus and to observe the topographical relation with the vertebrae. All animals showed five lumbar vertebrae and three sacral vertebrae. The vertebrae were in general very closed with the spinous processes well developed and directed cranially. The conus of capuchin monkeys was located between the L2 and L5 vertebrae, with the base mostly in the L3 vertebra, and the peak in L4. The body length (interarcual space occiptoatlântico until sacrocaudal interarcual space) ranged from 22.9 to 31.8cm, with a mean of 27.44±3.1cm while the medullary cone length ranged from 1.70 to 3.51cm, with a mean of 2.47±0.57cm. There was no correlation between body size and length of the medullary cone (r=0.212). It is concluded that despite the variations in length and positioning of the medullary cone, its height does not exceed the lumbosacral joint, making safe access to the epidural space in this way.

Anatomy of the spinal cord of Alouatta belzebul

“…After the dissection of the dorsal region, from the cranial region to the base of the tail, the spine of A. belzebul was evidenced and showed for all the specimens: 7 cervical vertebrae, 13 thoracic vertebrae, 5 lumbar vertebrae and 3 fused sacral vertebrae (Figure 1). A similar result was found by Silva et al (2013) for Callithrix jacchus and Cordeiro et al (2014) for Sapajus libidinosus. However, Lima et al (2011a) observed a total of 9 lumbar vertebrae for Saimiri sciureus, and Martins et al (2013) observed 7 lumbar vertebrae for Saguinus midas.…”

“…The morphological differences of both the measurement and the topography of the IC, IL, CM and CE among the species described in the literature, show the importance of knowing the location of these structures to apply anesthetics in surgical procedures, which is specific for each species. Silva et al (2013) states that epidural anesthetics should be applied in the lumbosacral region for Callithrix jacchus corroborating the findings of LA for this species, in Saguinus midas it should be applied in the spaces between the vertebral arches of the lumbosacral region (MARTINS et al, 2013), in Sapajus libidinosus, in the epidural space of the lumbosacral region (CORDEIRO et al, 2014) and in Saimiri sciureus in the girdle and pelvic limbs (LIMA et al, 2011a). For A. belzebul, epidural anesthesias should be applied in the lumbosacral region, specifically between L2 and S3 vertebrae.…”

Medullary Conus Topography in White-Tufted-Ear-Marmoset (Callithrix jacchus)

“…Em relação ao ratão-do-banhado (Myocastor coypus), uma espé-cie de roedor, também se observou uma semelhança, o qual possui a base do cone em L3-L5 e ápice em L4-L6 [10]. Quanto aos primatas, encontra-se para os macacos-prego, base em L2 e ápice em L5 [4], se assemelhando ao encontrado em Callithrix jacchus.…”

“…O valor médio do comprimento do cone medular da espécie Callithrix jacchus (1,4 cm) se apresentou mais próximo ao obtido para o ratão-do-banhado, o qual apresentou um valor médio de 2,0 cm [10], o macaco-prego, no qual foi encontrado valor médio de 2,47 [4], e a preguiça, que apresentou 2,7 cm [7], e significativamente menor do que as médias obtidas para o cachorro-do-mato (10,13 cm) [14], para o cachorro--do-mato-de-orelhas-pequenas (3,9 cm) [15], para o sauim (5,38 cm) [13], para o quati, que apresentou valor de 5,2 a 5,8 cm [5], para o macaco-de-cheiro (3,3 cm) [6], para a paca (3,39 cm) [18], para o javali (Sus serofa serofa), com valor de 3,4 cm [17], para o lobo-marinho (4,4 cm) [9], para o gato mourisco (5 cm) [3], para a ariranha (5,5 cm) [11], para a irara (4,31 cm) [1], para a jaguatirica (8,5 cm) [2], para o guaxinim (5,1 -5,6 cm) [21] e para o lobo-guará (6,5 cm) [8].…”

“…Visto que o ápice do cone medular em Callithrix jacchus se encontra no máximo até a sexta vér-tebra lombar, o espaço lombossacro é o local indicado para anestesia epidural, assim como indicada para o lobo-guará (Chrysocyon brachyurus) [8], a irara (Eira barbara) [1], a ariranha (Pteronura brasiliensis) [11], o guaxinim (Procyon cancrivorus) [21], o ratão-do--banhado (Myocastor coypus) [10], e o macaco-prego (Sapajus libidinosus) [4].…”