Endoscopic Trans-septal Trans-caval Inter-forniceal Approach to the Posterior Third Ventricle in Presence of Cavum Septum Pellucidum

Abstract Introduction Posterior third ventricular lesions often cause obstructive hydrocephalus. Thus, a combined endoscopic third ventriculostomy (ETV) and endoscopy biopsy are often the first treatment. However, the trajectories for both procedures may significantly differ, necessitating two entry points, or a combined rigid-flexible technique. Methods We describe the utilization of a large cavum septum pellucidum (CSP) as a route for performing the biopsy. Results Using a rigid endoscope and a single trajectory, we were able to perform a trans foraminal ETV, and a trans-septal, trans-caval, inter-forniceal biopsy of the tumor. Conclusions Although described as a route to endoscopically reach the anterior third ventricle, we describe the utilization of the trans-septal, trans-caval, inter-forniceal approach to reach the posterior part of the third ventricle.