Approaches to Third Ventricular Tumors

Abstract The removal of third ventricular tumors is one of the most challenging neurosurgical procedures. As it is known, manipulating the walls of the third ventricle may result in hypothalamic dysfunction, which is manifested by disturbances of consciousness, temperature, and hypophyseal secretion; visual loss due to damage to the optic chiasm; and memory loss due to injury to the columns of the fornix. The third ventricle is a narrow unilocular midline cavity. It communicates anteriorly with the lateral ventricles through the foramen of Monro and posteriorly with the fourth ventricle through the mesencephalic aqueduct (of Sylvius). The approaches to the anterior two-thirds of the third ventricle are directed through the frontal horn and body of the lateral ventricles, such as the interhemispheric transcallosal and the transcortical transcallosal approaches. The posterior part of the third ventricle is usually accessed through the posterior transcallosal or transcortical approach. Nevertheless, the supracerebellar infratentorial approach seems to be the most chosen approach to reach the posterior aspect of the third ventricle.