The supracerebellar approach, specifically the supracerebellar infratentorial approach, is a surgical technique used in neurosurgery to access lesions located in the posterior cranial fossa, particularly those situated in the midline or paramedian regions of the pineal gland, posterior third ventricle, and upper brainstem. This approach involves accessing these areas through a midline or paramedian incision in the cerebellum, underneath the tentorium cerebelli.
Indications for the Supracerebellar Approach Pineal Region Tumors:
Tumors of the pineal region, such as pineocytomas, pineoblastomas, germ cell tumors (e.g., germinomas, teratomas), and pineal cysts, are commonly accessed via the supracerebellar approach. This approach provides direct access to the pineal region without the need for extensive retraction of the cerebellum or the occipital lobe. Midbrain and Upper Brainstem Lesions:
Lesions located in the midbrain tectum (such as tectal gliomas) and upper brainstem are amenable to the supracerebellar infratentorial approach due to its direct line of sight to these structures. Cavernous malformations, gliomas, and other intrinsic brainstem pathologies may be accessed using this route when located dorsally.
Posterior Third Ventricle Tumors:
Tumors extending into or arising from the posterior third ventricle, such as colloid cysts or tumors of the choroid plexus, can be accessed through the supracerebellar approach, especially if they extend posteriorly or inferiorly.
Vascular Lesions:
Arteriovenous malformations (AVMs) and cavernous malformations in the region of the pineal gland, midbrain, and posterior third ventricle may be approached supracerebellarly. This approach can be useful for clipping aneurysms located in the posterior circulation, although this is less common.
Cerebellar Tumors:
While not the primary approach for most cerebellar tumors, the supracerebellar infratentorial route may be used if the lesion extends to or involves the tentorial surface of the cerebellum. Aqueductal Stenosis and Related Pathologies:
Some cases of aqueductal stenosis or other pathologies causing obstructive hydrocephalus may be approached through the supracerebellar approach, particularly when endoscopic options are not feasible or in recurrent cases. Advantages of the Supracerebellar Approach Direct Access: Provides a direct surgical corridor to midline structures without extensive brain retraction. Minimal Cerebellar Manipulation: Limits the manipulation of the cerebellar hemispheres, reducing the risk of cerebellar injury. Gravity-Assisted Retraction: When the patient is positioned sitting or in a semi-sitting position, gravity assists in cerebellar retraction, improving visualization. Considerations and Limitations Patient Positioning: The approach typically requires the patient to be in a sitting or semi-sitting position, which carries risks such as air embolism. Exposure Limitations: The approach is most suitable for midline and paramedian lesions; lateral lesions are less accessible. Surgical Expertise: The supracerebellar approach requires familiarity with the posterior fossa anatomy and experience in microsurgical techniques due to the critical structures in the region. In conclusion, the supracerebellar approach is a versatile and effective technique for accessing various lesions in the pineal region, midbrain, posterior third ventricle, and upper brainstem. It is chosen based on the location and type of lesion, as well as the surgeon's expertise and the patient's overall condition.
Several surgical approaches have been described for falcotentorial meningioma treatment. These include infratentorial supracerebellar approach.
A steep tentorial angle is an unfavorable preoperative radiographic factor for achieving maximal resection with the supracerebellar infratentorial approach. Collectively, a study of Zhao et al. showed that versatility is required to treat patients with falcotentorial meningiomas and that treatment goals and surgical approach must be individualized to obtain optimal surgical results 1).
The supracerebellar infratentorial approach provides a direct corridor to pineal tumors caudal to the deep veins; for tumours invaginating the tectal plate in a caudal direction the occipital transtentorial approach provides a better view 2).