Reparación de lesiones en nervios mediante el implante de prótesis obtenidas de segmentos acelulares de nervio isogénico / Repair of nerve injury by implanting prostheses obtained from isogenic acellular nerve segments

Introducción. Cuando se produce una sección nerviosa con separación significativa de los cabos es necesario utilizar una prótesis, a modo de puente, para suturarlos. La mejor prótesis es un segmento de nervio autógeno, pero presenta importantes inconvenientes. Nuestro objetivo es comparar la eficacia de la sutura simple con la tubulización para el implante de una prótesis de nervio isogénico descelularizado. Material y método. Se utilizan 4 grupos de ratas Wistar. Grupo 0: animales donantes de nervio ciático. Grupo 1: recibió el implante con sutura término-terminal. Grupo 2: recibió el implante dentro de un tubo de ??-caprolactona. Grupo 3: lo recibió en un tubo de poliláctico-co-glicólico. Se evaluó la función motora (índice ciático) y la extensión de la regeneración (estudio histológico) a las 3 semanas del implante. Resultados. La regeneración ha sido irregular en los 3 grupos experimentales. En todos hay implantes en los que las fibras nerviosas regeneran la longitud máxima estudiada (15mm) y otros en los que la regeneración es muy escasa. La longitud media de regeneración es mayor en el grupo de sutura directa (G1), aunque la velocidad es similar en los 3. El grupo 1 muestra el mayor porcentaje de regeneración, aunque la variabilidad de los resultados impide que esta diferencia alcance significación estadística. No hemos hallado diferencias significativas entre los dos grupos con tubos de diferentes polímeros. Conclusión. Para implantar prótesis de nervios isogénicos descelularizados es más eficaz, en nuestras condiciones experimentales, la sutura término-terminal que los tubos de polímeros biocompatibles (AU)

Introduction. When a nerve section with a significant gap occurs, it is necessary to use a prosthesis to suture it. To date an autologous nerve segment graft appears to be the best treatment; but it has several important disadvantages. Our goal is to study the effectiveness of an isogenic acellular nerve prosthesis comparing a simple suture with tubulisation. Material and method. Four groups of Wistar rats were used. The animals in Group 0 served as donors of nerve segments to graft. Group 1 received the implant with an end-to-end suture. In group 2, the implant was sutured inside an ??-caprolactone tube. Group 3 received it in a polylactic-co-glycolic acid tube. We evaluated the motor function (sciatic index and step test in motion), and the regeneration length by histological study of regeneration, after a maximum of 3 weeks. Results. Regeneration was uneven in the three groups. In all groups, there were implants with regenerated nerve fibres at the maximum studied length (15mm) and others where regeneration was scarce. The mean regeneration length was greater in the direct end-to-end suture group (G1), although the regeneration speed was similar in the three groups. Group 1 showed the highest percentage of regeneration, but the variability of results prevents this difference reaching statistical significance. We found no significant differences between the two groups with polymer tubes. Conclusion. For the implantation of isogenic acellular nerve prosthesis, under our experimental conditions, the direct end-to-end suture was more effective than when it isprotected with biopolymer tubes (AU)

Repair of nerve injury by implanting prostheses obtained from isogenic acellular nerve segments. / Reparación de lesiones en nervios mediante el implante de prótesis obtenidas de segmentos acelulares de nervio isogénico.

INTRODUCTION: When a nerve section with a significant gap occurs, it is necessary to use a prosthesis to suture it. To date an autologous nerve segment graft appears to be the best treatment; but it has several important disadvantages. Our goal is to study the effectiveness of an isogenic acellular nerve prosthesis comparing a simple suture with tubulisation. MATERIAL AND METHOD: Four groups of Wistar rats were used. The animals in Group 0 served as donors of nerve segments to graft. Group 1 received the implant with an end-to-end suture. In group 2, the implant was sutured inside an ɛ-caprolactone tube. Group 3 received it in a polylactic-co-glycolic acid tube. We evaluated the motor function (sciatic index and step test in motion), and the regeneration length by histological study of regeneration, after a maximum of 3 weeks. RESULTS: Regeneration was uneven in the three groups. In all groups, there were implants with regenerated nerve fibres at the maximum studied length (15mm) and others where regeneration was scarce. The mean regeneration length was greater in the direct end-to-end suture group (G1), although the regeneration speed was similar in the three groups. Group 1 showed the highest percentage of regeneration, but the variability of results prevents this difference reaching statistical significance. We found no significant differences between the two groups with polymer tubes. CONCLUSION: For the implantation of isogenic acellular nerve prosthesis, under our experimental conditions, the direct end-to-end suture was more effective than when it isprotected with biopolymer tubes.

Intra-rachidian disorders: two unusual cases of recurrent abdominal pain in children.

UNLABELLED: Recurrent abdominal pain (RAP) is generally thought to be of psychological origin but organic aetiologies are increasingly being identified. The cases of two children with vertebral disorders revealed by recurrent abdominal pain are reported. A 14-y-old girl presented with RAP associated with scoliosis, due to a T8-T9 intra-dural extra-medullary tumour. A 7-y-old girl who suffered from nocturnal RAP located in the right iliac fossa for 1 y had decreased muscular strength, pyramidal signs, and a 10 degree Lassègue sign in the right lower limb, revealing a vascular malformation extending from T12 to L2. CONCLUSION: Atypical pain and associated neurological signs or scoliosis must raise the possibility of intra-rachidian disorders. Magnetic resonance examination will then precisely state the location and nature of the pathological process, avoiding excessive delay in therapeutic management.

[Spinal cord metastasis: an uncommon location. Experience in 2 cases]. / Metástasis en la médula espinal: una localización infrecuente. Experiencia en 2 casos.

Spinal cord metastases are an uncommon secondary location of a malignant neoplasm. They are rarely diagnosed during life and when that is the case, it is in the clinical setting of a disseminated cancer and very seldom as the first clinical manifestation. We report two patients, with no previous disease, who developed a progressive myelopathy. An intramedullary spinal cord tumor was diagnosed, based on the clinical picture and imaging studies. They were operated and biopsies showed spinal cord metastases whose primary tumor was a lung neoplasm. We discuss the clinical features in these patients, the diagnosis of progressive myelopathy in cancer patients, treatment and prognosis of this unusual secondary cancer location.

[Cerebral metabolic monitoring experience in critical neurological patients]. / Experiencia en monitorización metabólico-cerebral en pacientes críticos neurológicos.

BACKGROUND: Cerebral metabolic monitoring in critical neurological patients allows the assessment of neuronal tissue response to injury and to plan the best therapy to correct each critical brain situation. AIM: To evaluate the usefulness of cerebral metabolic monitoring in patients with acute cerebral injury. PATIENTS AND METHODS: A retrospective analysis of 29 patients with acute brain injury, in whom a catheter was located in the bulb of the jugular vein to perform a cerebral metabolic monitoring. These patients were compared with others that were not subjected to this monitoring. The evolution at six months of follow up was assessed using the Glasgow outcome score, considering a favorable evolution when this score was 4 or greater. RESULTS: Patients with an hyperemic state on admission or after optimization of therapy did not have hospital mortality, and 73% had Glasgow outcome score of 4 or greater at six months of follow up. On the other hand, 50% of those with hypoperfusion or global ischemia died during hospitalization and 72% had a Glasgow outcome score of 3 or less at six months. Patients not subjected to cerebral metabolic monitoring behave as those with hypoperfusion or global ischemia. CONCLUSIONS: Cerebral metabolic monitoring is an useful tool to optimize the management of patients with acute cerebral injury, and those patients with an hyperemic cerebral state have the best prognosis.

Protracted vomiting as the presenting sign of posterior fossa mass lesions.

Four patients with mass lesions of the posterior fossa experienced protracted vomiting as their only symptom for extended periods of time. The responsible lesions were a cerebellar tumour in two patients, a ventricular cysticercus in one patient, and a giant vertebral artery aneurysm in another. All four cases had compression or displacement of the floor of the fourth ventricle, where the "vomiting centre" has been located. The value of vomiting as a sign of a posterior fossa lesion is emphasised.

Intracranial cavernous angioma: presentation and management.

Thirteen cases of cerebral cavernous angiomas are reported, and their radiological and pathological features are reviewed. The clinical presentation was variable: 53.8% of patients had seizures, 30.8% intracerebral hemorrhage, and 15.4% focal neurological signs, including one unusual case that presented as a cerebellopontine angle tumor. The computerized tomography (CT) scans were abnormal in all cases. Angiography was positive only when there was mass effect due to associated hematoma. Surgery was performed in 12 cases with good results. The prognosis of the 13 cases was favorable, with no mortality in this series. These data suggest that the combination of a recent seizure disorder with a hyperdense intracerebral nodule on the CT scanning should alert the neurosurgeon to the possibility of a cavernous angioma.

Cysticercosis of the central nervous system: clinical and therapeutic considerations.

In a group of forty cases of cysticercosis of the central nervous system, 59% presented with intracranial hypertension due to obstructive hydrocephalus. Ventricular or cisternal cysts, and chronic cysticercus meningitis were the most common causes of hydrocephalus. Seizures occurred in 40% of the patients, in one-half of them in association with CT-detected parenchymatous cysts. In 20% of the cases progressive mental deterioration was the main clinical feature, at times associated with hydrocephalus. CT scan provided the highest diagnostic yield, being abnormal in 90% of cases. Long term prognosis was poor, with a mortality rate of 38% over a 40-month follow-up period. The most common cause of death (60%) was meningitis. CSF shunting is the treatment of choice for hydrocephalus, irrespective of its mechanism. Surgical resection is indicated in some cases with a single superficial (cortical) or posterior fossa cyst. Supratentorial cysts carry a relatively benign prognosis.

Sonography of the posterior fossa.

An anatomic correlation of sonographic images and anatomy in cadavers was undertaken to establish a foundation for sonographically assisted recognition of structures and their relation to pathology. Such information would be useful for orientation purposes during surgery, for biopsies, and for follow-up studies. A specially designed technique of placing metal markers with sonographically guided needles was used. Anatomic cuts and dissections were subsequently performed. Sonographic clinical material obtained during surgery and in postoperative controls was analyzed based on this experimental work and previous investigations in this area. Detailed anatomy of the posterior fossa can be demonstrated with sonography.