[Petrectomy of the point during approach to the clivus: technic, values and limitations. Apropos of a case of meningioma].

A voluminous clivus meningioma was removed by a middle fossa transpetrous approach. We describe the surgical technique, with its advantages and its limits. The petrous bone was burred between the internal auditory canal, the internal carotid artery, the superior petrosal sinus and the inferior petrosal sinus. This approach gives excellent exposure of the clivus, anterior to the brainstem and the cranial nerves. This approach can be used for removal of voluminous intradural tumors arisen anterior to the internal auditory canal, and for clipping of aneurysms of the basilar artery. It appeared that the choice of the side for this approach must only depend on the extension of the tumour and displacements of the brainstem and the basilar artery, without concern on the hemispheric lateralization.