[Endoscopic anatomy of the third ventricle].

According to the development of neurosurgical endoscopy (and especially for third ventriculostomy), the endoscopic anatomy in hydrocephalus should be well known and utilized for orientation. The endoscopic pictures are obtained with a 30; telescope, acquired by a digitalized camera and visualized on a video monitor. The pictures are then numerized on a DKR system. Endoscopic anatomy of the third ventricle is described with a particular focus on the anatomical landmarks and their variations around the foramen of Monro, the anterior and posterior walls of the third ventricle. The knowledge of this anatomy is essential for the safety and the reliability of intraventricular endoscopic procedures.