Supracerebellar transtentorial approach

Aim: The aim of this work was a retrospective evaluation of the safety of the supracerebellar transtentorial approach in our patient series. It represents a technically challenging approach, which we used during surgeries of the posterior and medial mediotemporal area, lateral mesencephalon and posteromedial thalamus. Materials and methods: We evaluate the series of our 8 patients, which we operated on using the supracerebellar transtentorial approach during 2013-2021. In one case, we dealt with anaplastic astrocytoma, 3x with glioblastoma multiforme primary surgery, 1x with diffuse midline H3K27M glioma, 1x with glioblastoma multiforme recurrence surgery, 1x with low-grade glioma surgery and once we operated using this approach an acutely bleeding cavernoma of the lemniscal trigone of the mesencephalon. All our patients were operated on in a semisitting position. Results:The thirty-day mortality rate of our series is zero. In case of a patient with diffuse midline H3K27M glioma which was primarily operated on in a bad neurological condition, we had to perform early revision surgery using the same approach due to residual tumor hemorrhage. In case of our first patient with extensive mediotemporal anaplastic astrocytoma, we had to add the suboccipital approach for resection radicality increase early after the first phase of surgery; after the surgery, he had superior quadrantanopsia. In one patient's case, ischemia of the occipital lobe occurred due to an intraoperatively visible lesion of the posterior cerebral artery inside the glioblastoma. After surgery, hemianopsia was present. Conclusion: The approach poses a technically challenging, but concurrently safe surgical trajectory. In case of the lesions affecting the mediotemporal area, it is advantageous for its medial and posterior part, but during the resection it is possible to reach as far as the uncus and amygdala. The prerequisite condition is accurate anatomical knowledge; in our department, we prefer the semisitting position for this approach. It is important to have a sufficient cerebrospinal fluid decompression by releasing the fluid from the cisterna magna from a separate dural incision and a gentle manipulation of the vascular structures of the tentorial incisura.