Endoscopic Supracerebellar Transtentorial Approach to Atrium of Lateral Ventricle: Preliminary Surgical and Optical Considerations.

Objective We sought to report the operative techniques of the endoscopic supracerebellar transtentorial approach (ESTA) to the atrium of the lateral ventricle, especially focusing on the role of the endoscope and analyzing optically related issues. Methods A retrospective data review was performed on 5 patients with lesions in the atrium of the lateral ventricle undergoing the ESTA. The patients were positioned in the three quarters prone position, and a paramidline linear incision was used. After performing a suboccipital craniotomy extending immediately above the transverse sinus and tentorium incision with precisely neuronavigation, corticotomy in the posterior mediobasal temporal region created a corridor to the tumor. All of the procedures were performed with an endoscope in a pneumatic arm holder. The preoperative and postoperative perimetry test and diffusion tensor imaging fiber tracking of the optic radiations were compared and analyzed. Results Three patients had meningiomas, and 2 patients had high-grade gliomas in the atrium. The meningiomas were totally removed, and the gliomas were subtotally resected. One patient with glioblastoma died 2 months later after surgery because of the tumor progression; the remaining 4 patients had a visual field deficit without any other neurologic complications. The endoscope improved the surgical viewing angle, which was restricted by the microscope and slope of the tentorium. Conclusions ESTA is an alternative route to the atrium of the lateral ventricle. However, the collateral sulcus, which is highly relied on in neuronavigation, is illegible in the limited area. And the visual field deficit remains the primary challenge with this approach.