Basilar Venous Plexus, Inferior View

Description

Seen from below, the basilar venous plexus forms a blue, reticular channel network along the clivus, positioned in the midline anterior to the pons and inferior to the dorsum sellae. Lateral to this plexus, the paired inferior petrosal sinuses track toward the jugular foramina, linking the basilar plexus with the cavernous sinus region and the internal jugular venous system. Arterial anatomy in red frames the field, with the vertebral arteries joining to form the basilar artery on the ventral surface of the brainstem, while yellow cranial nerves emerge from the midbrain and pontomedullary junction and course anterolaterally. Midline relationships are the point. An inferior perspective matters because the basilar venous plexus is a major emissary pathway between the cavernous sinus and the vertebral venous plexus, and it sits directly against the skull base where infection and thrombosis can spread in clinically unintuitive directions. Venous bleeding along the clivus can complicate endoscopic endonasal transclival approaches to the petroclival region, and familiarity with the inferior petrosal sinus trajectory is central when interpreting petrosal sinus sampling for ACTH-dependent Cushing disease. This view also clarifies why basilar artery aneurysm surgery and ventral brainstem exposure must account for adjacent cranial nerve root exit zones. Use this illustration in neuroanatomy and neurosurgery teaching to correlate skull base venous channels with the ventral brainstem, in radiology education to orient MR venography and CTA at the clivus and petroclival junction, and in operative atlases covering transsphenoidal, transclival, and posterior fossa approaches. Anatomical accuracy verified by SciePro's Medical Advisory Board.