Magnetic resonance imaging-directed stereotactic endoscopic third ventriculostomy.

Third Ventriculostomy has been proposed as the procedure of choice for many patients with acquired obstructive hydrocephalus. Various techniques have been used to perform this procedure. This report describes the use of magnetic resonance images to guide the performance of a stereotactic third ventriculostomy with a rigid endoscope, allowing continuous direct visualization. This procedure has been performed on three patients, yielding clinical improvement without the need for extracranial shunting. Magnetic resonance imaging allows accurate identification of the important anatomical landmarks (i.e., foramen of Monro and interpeduncular cistern), with axial, coronal, and sagittal images, and is readily used in conjunction with the Cosman-Roberts-Wells stereotactic apparatus.