Cranial Venous Anatomy
Cerebral venous anatomy can be divided into the cerebral and posterior fossa anatomical compartments. The cerebral venous configuration can be subdivided into a deep (subependymal) and superficial group. The superficial division, as Rhoton described, is a series of draining veins that can be grouped into four groups of bridging veins: a superior sagittal group, sphenoidal group, tentorial group, and falcine group. The high variation in location and dominance of the veins within these anatomical regions demonstrates the need for a region-based division.
The deep veins include those that drain the walls of the ventricles, choroid plexi, and basal cisterns. These structures include the basal venous system, internal cerebral venous system, and the vein of Galen.
The deep and superficial cerebral venous groups then converge on the major draining sinuses, which include the superior sagittal sinus, inferior sagittal sinus, straight sinus, transverse sinuses, tentorial sinuses, cavernous sinuses, superior petrosal sinuses, sphenoparietal sinuses, sphenobasal sinuses, and sphenopetrosal sinuses. The majority of the drainage from the major draining sinuses converges on the internal jugular veins, which serve as the major outflow from the cranial vault.
The posterior fossa venous structures can be divided into four divisions: superficial, deep, brainstem, and bridging veins. Rhoton further subdivided the superficial draining veins into tentorial, suboccipital, and petrosal draining surfaces. The three superficial surfaces, deep posterior fossa veins along the cerebellar fissures, and plexi along the brainstem drain into one of the three groups of bridging veins: galenic, petrosal, or tentorial. The galenic group drains to the vein of Galen. The petrosal group drains into the inferior or superior petrosal sinuses. The tentorial group drains into the tentorial sinuses that ultimately drain onto the superior petrosal, straight, or transverse sinuses.