RESUMEN
Introducción: Las "zonas de entrada seguras" (ZES) al tronco cerebral describen accesos destinados a preservar estructuras críticas. La mayoría de las publicaciones son descripciones anatómicas; existiendo pocas sobre su aplicación. En este escenario, nuestro trabajo puede sumar información para el manejo quirúrgico en casos seleccionados. Material y Métodos: De una serie de 13 pacientes, se presentan 9 que no eran candidatos para biopsia estereotáctica y recibieron microcirugía. Las localizaciones fueron: mesencéfalo (3), tectum (1), protuberancia (2) y bulbo (3). Cinco pacientes tuvieron KPS => 70; y 4, KPS <70. Diferentes ZES fueron utilizadas según la topografía lesional. El grado de resección se basó en la biopsia intraoperatoria y el monitoreo neurofisiológico. Resultados: Los hallazgos patológicos fueron: astrocitoma pilocítico (1), glioma de bajo grado (1), hemangioblastoma (1), subependimoma (1), disgerminoma (1), y lesiones pseudotumorales (3 cavernomas y 1 pseudotumor inflamatorio). El grado de resección fue completo (4), subtotal (3), y biopsia fue considerada suficiente en (2). Un paciente falleció en el postoperatorio. Discusión: Las lesiones del tronco cerebral son infrecuentes en adultos. Las controversias surgen cuando se balancean los beneficios de obtener diagnóstico histopatológico y los riesgos potenciales de procedimientos invasivos. La amplia variedad de hallazgos en esta localización exige una precisa definición histopatológica, que no solamente determinará la terapéutica adecuada, sino que advierte sobre las consecuencias potencialmente catastróficas de los tratamientos empíricos. Las ZES ofrecen un acceso posible y seguro, aunque es más realista considerarlas como áreas para abordar lesiones intrínsecas con baja morbilidad más que como zonas completamente seguras
Introduction: The "safe entry zones" (SEZ) to the brainstem are special entrances described to preserve critical structures. Most publications correspond to anatomic research; few papers report their application in surgery. In this scenario, our report could add information to the surgical management in selected cases. Material and Methods: Out of a series of 13 patients, 9 were non-candidates for stereotactic biopsy and received microsurgery. Localizations of the lesions were: mesencephalus (3), tectal plate (1), pons (2) and medulla oblongata (3). Five patients had KPS => 70; 4, KPS <70. Different SEZ were used according to lesional topography. The extent of resection were based on the frozen pathology findings and neurophysiological monitoring. Results: A variety of pathological findings were found: low-grade glioma (1); pilocytic astrocytoma (1); hemangioblastoma (1); subependimoma (1); disgerminoma (1); pseudotumoral lesions (cavernomas 3 and inflammatory pseudotumor 1). The extent of resection was complete (4), subtotal (3), and biopsy was considered sufficient in 2 cases. One patient died 96-hours-postoperative due to brainstem edema. Discussion: Brainstem structural lesions are uncommon in adults. Controversies arise regarding the need of histologic diagnosis, weighing benefits of a reliable diagnosis and the potential disadvantages of the invasive procedures. The accurate histopathological definition could not only determine an adequate therapy, but also can prevent the disastrous consequences of empiric treatments. The SEZ provides a feasible and safe access, although it is more realistic to consider them as areas to approach intrinsec lesions with less morbidity than to consider them as completely safe entrances
Asunto(s)
Tronco Encefálico , Patología , Terapéutica , Mesencéfalo , MicrocirugiaRESUMEN
CONTEXT: Low-grade astrocytomas are intracerebral lesions of relatively high frequency in the under-18 pediatric population. They often present indolent behaviour, and complete surgical resection is the choice treatment. In cases where the surgery is not possible, chemotherapy and radiotherapy may be used. Medical reports do not recommend examination of the spinal cord at diagnosis or during treatment, since the risk of dissemination of the lesion to the spine is minimal according to medical experience. We describe here four cases of children with low-grade astrocytoma with aggressive dissemination to the neuroaxis.
CONTEXTO: Gliomas de baixo grau de malignidade são lesões intracerebrais relativamente freqüentes na população pediátrica menor de 18 anos de idade. Eles freqüentemente são indolentes em seu comportamento e a ressecção cirúrgica completa é o tratmento de eleição. Nos casos em que a cirurgia não é possível, a quimioterapia e a radioterapia podem ser utilizadas. Relatos da literatura não recomendam a avaliação radiológica da coluna espinhal ao diagnóstico ou durante o tratamento, desde que o risco de disseminação destas lesões para a coluna é considerado mínimo. Descrevemos aqui quatro casos de crianças com gliomas de baixo grau de malignidade com disseminação agressiva para o neuroeixo.