Classification of dural arteriovenous shunts (DAVS) based on the craniospinal epidural venous drainage of the central nervous system and adjacent bony structures

Abstract

The cranio spinal epidural spaces were categorized into three different compartments - ventral, dorsal and lateral. Each compartment has its specific drainage role in relation to the embryologic development of the venous system of the central nervous system (CNS) and the surrounding bony structures. The ventral epidural space drains structures derived from the notochord and adjacent sclerotomes. The dorsal epidural group is related to the drainage of the spinous processes at the spinal level and to the vault and calvarium cranially. The lateral epidural group collects the emissary bridging veins of the pial venous system of the spinal cord and brain. The dural arteriovenous shunts (DAVS) developing in these spaces predictably drain either in the subarachnoid veins or in the epidural-paraspinal collectors according to the epidural compartment involved. Additional comorbidity, like epidural venous thrombosis or high flow characteristics of the DAVS, will be responsible for changes in the draining pattern of otherwise anticipated spinofugal or craniofugal drainage. This embryologically based classification establishes homologies between spinal and cranial epidural spaces, thus allowing epidemiological and clinical comparison including spinal and cranial DAVSs.