Venous Lacunae

Description

Centered along the cranial midline, the superior sagittal sinus runs within the attached margin of the falx cerebri, receiving multiple venous lacunae (lacunae laterales) that spread laterally between the periosteal and meningeal layers of dura mater. Bridging veins from the superficial cerebral veins traverse the subdural space to enter these lacunae and the sinus, with arachnoid granulations often projecting into the lacunar spaces before draining into the venous channel. The cortical surface of the cerebral hemispheres provides the backdrop, while inferiorly the brainstem continues into the cervical spinal cord, with spinal nerve roots exiting laterally from the cord at successive levels. Color coding distinguishes arterial versus venous pathways and keeps the cranial vasculature visually separate from the peripheral nerves. Venous lacunae matter because they sit at the junction of cerebral venous outflow and cerebrospinal fluid resorption, a relationship that becomes clinically visible when bridging veins tear and bleed into the subdural compartment after acceleration or deceleration injury. Neurosurgeons also watch this region during parasagittal craniotomy and falx-based approaches, where injury to bridging veins or the superior sagittal sinus can cause difficult-to-control hemorrhage and postoperative venous infarction. A frequent teaching point. Parasagittal meningiomas may narrow or invade the sinus and its lacunae, altering venous drainage patterns that guide operative planning. Neuroanatomy and neuroradiology courses use this view to teach dural venous sinus anatomy, the route of superficial cerebral veins, and why the midline differs from deep venous drainage into the straight sinus. It also fits operative atlases discussing interhemispheric approaches, sinus exposure, and complications such as subdural hematoma or cerebral venous sinus thrombosis affecting the superior sagittal sinus and adjacent lacunae. Anatomical accuracy verified by SciePro's Medical Advisory Board.