Third ventriculostomy by microtechnique.

The microtechnical approach to third ventriculostomy is presented. Opening of the lamina terminalis and basal membrane of the floor of the third ventricle is combined with opening of the membrane of Liliequist. The technique was used in five cases of aqueductal stenosis. We stress the importance of the microscope, and opening of the membrane of Liliequist to gain additional access.