A neuroendoscopic approach to the ventral brainstem

The microsurgical approach to the ventral brainstem is difficult and danger ous. In most cases, the aim of neurosurgical treatment of brainstem tumours is to obtain a histological sample and decompress the cystic parts of the tumour: We describe a new access to the ventral brainstem achieved using a combination of stereotaxy and endoscopy A 2 1/2 year old boy began to show a noticeable somatic standstill, with increasing ataxic gait and dysarthria . MRI scans of the skull showed that the entire pens was taken over by a di ffuse growing lesion, blocking the aqueduct. We carried out a stereotactic- guided neuroendoscopic-fenestration of the floor of the third ventricle. A biopsy from the tumour was taken under vision through the stoma. The histol ogical diagnosis revealed a fibrillary astrocytoma The MRI control showed a sufficient ventriculostomy. The hydrocephalus resolved postoperatively. Th e boy died 15 months after the operation. A stereotactic-guided biopsy unde r neuroendoscopic vision can be performed with relative safety. The neuroen doscopy allows an approach into the area of the ventral brain stem which is usually difficult to access.