Endoscope-assisted infratentorial-supracerebellar approach to the third ventricle:an anatomical study

Object. The authors studied the microsurgical anatomy and endoscopic features of the pineal region and third ventricle to describe a combined microsurgical–endoscopic infratentorial–supracerebellar approach to the posterior third ventricle. Such an approach exposes the pineal gland and its complex neurovascular structures so that the third ventricle can be reached through a minimally invasive parapineal incision. Methods. The approach was studied in 10 adult cadaveric heads, six fresh and four formalin fixed, by using an operative microscope with a magnification level of 6 to 40 and the assistance of an endoscope. The endoscope-assisted infratentorial–supracerebellar approach affords a complete view of the third ventricle from a posterior perspective. The third ventricle is entered through a parapineal incision using the natural space between the internal cerebral vein and the vein of Rosenthal located above the superior colliculi. Conclusions. The infratentorial–supracerebellar approach to the third ventricle follows a natural corridor and requires minimal retraction and resection of critical neural structures. With the use of the endoscope, an unsurpassed view into the third ventricle from a posterior perspective is obtained. KEY WORDS • pineal region • third ventricle • endoscopy • microsurgical anatomy • infratentorial–supracerebellar approach • pediatric neurosurger