Reappraisal of the infratentorial supracerebellar approach

The infratentorial supracerebellar approach (ISCLA) is suitable for the removal of tumors in the pineal region. It can also be used for pathology of the thalamic, midbrain-tectal, tegmento-pontine and cerebellar regions. During the last 3 years, 29 patients underwent this approach in the sitting position: 22 usual median ISCLA and 7 paramedian ISCLA (Yasargil). Total removal of pathology was accomplished in 20 cases and partial or subtotal removal in 9 cases. No mortality and two cases of neurological deterioration were observed: one hemiparesis with “thalamic hand” in one patient, and persistent Parinaudʹs syndrome in one patient. The following principal observations can be made from our experience: (1) Pineal and thalamic pathology should be submitted to the usual median ISCLA. (2) Unilateral colliculo-midbrain pathology and tegmento-pontine pathology should be submitted to paramedian ISCA. (3) Removal of a colliculus superior on one side does not seem to produce any disturbance of occular movement. (4) Neither procedure gives adequate access to pathology of the floor of the third ventricle, so that an invasive procedure such as division of the colliculi in the midline might be taken into consideration. Details of technique and results will be discussed along with a review of the literature.