Longstanding hydrocephalus and raised intracranial pressure canlead to unusual anatomical variants in the floor of the third ventricle, which may be important when performing endoscopic third ventriculostomy. Two middle aged patients with symptomatic longstanding hydrocephalus had scans that showed ventricular hydrocephalus, an emptysella, and a dilated infundibular recess which herniated into the sellaturcica. Endoscopic third ventriculostomy confirmed that instead of thetuber cinerum and infundibular recess, the anterior inferior floor ofthe third ventricle was hanging down ventral to the pons into thesellar floor. Third ventriculostomy to the prepontine cistern was madeon the dorsal wall of the dilated infundibular recess to the areasurrounded by the dorsum sellae, the basilar artery trunk, and the leftsuperior cerebellar artery, with good symptomatic control. Associationof the empty sella and persistence of the infundibular recess must becarefully evaluated by MRI before attempting endoscopic thirdventriculostomy. Herniation of the anterior inferior floor of the thirdventricle into the empty sella can lead to loss of anatomical landmarksthat require special attention during third ventriculostomy.
展开▼
