RESUMEN
An experimental model of a seamless end-to-end joining of severed sciatic nerve (with gaps between the two ends 5-8 mm-wide) using an implanted arterial vessel was elaborated on random bred and inbred Wistar rats. Histological examination showed that nerve regeneration along the implanted arterial lumen was directly oriented and was not accompanied by neuroma formation which was always the case in the control. It took some nerve fibers 20 days to join the gap between the cut nerve ends. In 4 months myelination of regenerating fibers was observed in the blood vessel lumen, in 3 months the lumen was filled with bundles of myelinated fibers, and in 9 months the structure of the regenerating nerve was similar to that of the mature trunk observed in animals. The elaborated experimental model is to be employed in the studies of reparatory histogenesis in peripheral nervous tissues. The data obtained may be used in neurosurgery.
Asunto(s)
Fibras Nerviosas/cirugía , Regeneración Nerviosa , Animales , Masculino , Métodos , Fibras Nerviosas/lesiones , Ratas , Ratas EndogámicasAsunto(s)
Nervios Periféricos/cirugía , Animales , Humanos , Compresión Nerviosa , Fibras Nerviosas/lesiones , Ratas , Factores de TiempoRESUMEN
The development of nerve fiber bundle defects in monkey eyes by means of intraocular retinal coagulation, such as endodiathermy, intraocular cryotherapy or endophotocoagulation was confirmed by ophthalmoscopy. Two to 4 days after the application of intraocular retinal coagulation, the findings could be already observed. Endodiathermy especially could provide the typical ophthalmoscopic findings of nerve fiber bundle defects without any abnormal fluorescein angiographic findings, while endophotocoagulation and intraocular cryotherapy induced hyperfluorescence due to window defect at the coagulation site. Therefore, endodiathermy in monkey eyes can provide an excellent ophthalmoscopic model of the nerve fiber bundle defects. Histological findings 8 weeks after the coagulation showed thinning of the retinal nerve fiber layer and gliosis occurring in the retinal portion corresponding to the lesion.
Asunto(s)
Fibras Nerviosas/lesiones , Retina/lesiones , Procedimientos Quirúrgicos Operativos/efectos adversos , Animales , Quemaduras/patología , Criocirugía/efectos adversos , Electrocoagulación/efectos adversos , Angiografía con Fluoresceína , Terapia por Láser , Rayos Láser/efectos adversos , Macaca , Retina/patología , Retina/cirugíaRESUMEN
The ultrastructure of reinnervated Herbst corpuscles shows that the regenerating nerve branches appear in the inner zone of the receptors at the end of the first month after nerve crush. The nerve branches are accompanied by the Schwann receptor cells. Two periods of regeneration can be established. During the first period the changes reflect mainly the quantitative relations between the regenerating nerve branches and the Schwann receptor cells, whereas during the second period the intracytoplasmic and intraaxoplasmic renewal of the organelles take place. The final regeneration of the receptors finishes at the end of the fifth month after nerve crush and one month later after nerve transection. Also, after transection the number of reinnervated receptors is less encountered.
Asunto(s)
Patos/anatomía & histología , Mecanorreceptores/ultraestructura , Degeneración Nerviosa , Regeneración Nerviosa , Animales , Mecanorreceptores/fisiología , Microscopía Electrónica , Fibras Nerviosas/lesiones , Factores de TiempoRESUMEN
The first signs of reinnervation of the Pacinian corpuscles have been established at the middle of the second month after nerve crush. The regenerative process pass through two periods. During the first period the progressive increase of the Schwann receptor cells has been observed parallel to the reduction of the regenerating nerve branches. During the second period the reorganization and renewal of the regenerated organelles takes place. Some organelles as dense core vesicles, coated vesicles and microtubules of the receptor nerve fibre show noticeable dynamics. The regeneration has been established only in the preexisting after denervation capsulated remnants of the receptors. After nerve transection the regeneration is prolonged one month later and the less of quantity reinnervated receptors have been observed.
Asunto(s)
Mecanorreceptores/ultraestructura , Degeneración Nerviosa , Regeneración Nerviosa , Corpúsculos de Pacini/ultraestructura , Animales , Gatos , Masculino , Mecanorreceptores/fisiología , Microscopía Electrónica , Fibras Nerviosas/lesiones , Corpúsculos de Pacini/fisiología , Factores de TiempoAsunto(s)
Traumatismos de la Mano/patología , Traumatismos de los Tendones/patología , Amputación Traumática/patología , Anestesia , Fracturas Óseas/patología , Mano/inervación , Traumatismos de la Mano/clasificación , Traumatismos de la Mano/etiología , Traumatismos de la Mano/rehabilitación , Traumatismos de la Mano/cirugía , Humanos , Inmovilización , Luxaciones Articulares/patología , Bloqueo Nervioso , Fibras Nerviosas/lesiones , Fibras Nerviosas/cirugía , Tejido Nervioso/cirugía , Cuidados Posoperatorios , Cuidados Preoperatorios , Reimplantación , Traumatismos de los Tendones/clasificación , Traumatismos de los Tendones/cirugía , Procedimientos Quirúrgicos VascularesRESUMEN
Nerve injury can arise as a complication peripheral nerve block anesthesia. Of the various factors involved, the trauma caused by the injection needle may be of significance. In this experimental study the frequency of fascicular injury was investigated immediately after needling isolated rabbit sciatic nerve preparations, and after intraneural injection with the nerve in situ. Two different injection needles were used, one with a bevel angle of 14 degrees and the other with a 45 degrees bevel angle. Fascicular injury was indicated by a fluorescence microscopy technique, tracing locally applied Evans Blue Albumin, The results show that a 45 degrees-beveled needle less frequently produces fascicular damage and should therefore be recommended for use in clinical anesthesia. It is also concluded that paresthesiae, when necessary, should be elicited gently, and that intraneural injections should be avoided.