Proposal for an improved classification system for cavernous sinus dural arteriovenous fistula (CS-DAVF)

The existing classification systems for dural arteriovenous fistula (DAVF) and cavernous sinus DAVF (CS-DAVF) are inadequate for modern practice. Neither of the widely used systems deals with the key morphological and hemodynamic properties of CS-DAVF. In this paper, a modification of the existing, generally used, classification system for DAVF is advanced to incorporate a more satisfactory description of CS-DAVF. Current classification1 and treatment of CS-DAVF is problematic. Most useful disease classifications permit understanding of the morphology of a disease or lesion, to gain insight into the natural history and/or prognosis of a particular disease/lesion, and/or to indicate the treatment options available for the lesion. The main classification system applied to CS-DAVF has been the Barrow classification1 (table 1), which describes at least two separate disease entities. View this table: Table 1 Barrow classification of CS-DAVF Barrow type A fistulae are lesions resulting from ruptured intracavernous aneurysms, spontaneous intracavernous carotid dissections, and traumatic carotid transection/dissection. Types B–D reflect a different disease entity and etiology from type A—that is, CS dural fistula. While types B–D reflect a single disease (DAVF), the stratification of lesions according to their internal carotid artery (ICA), external carotid artery (ECA) or ICA+ECA connections is arbitrary and conveys no information about the draining anatomy and hemodynamics of the lesion, both of which are relevant for the natural history, prognosis, and treatment. Incorporating aneurysmal/dissecting/traumatic caroticocavernous fistula into this classification is equally arbitrary in that the etiology, prognosis, and management of the condition may be completely different from types B–D. The Cognard classification of DAVF2 (table 2) deals with some of the morphological and hemodynamic features absent from the Barrow classification. View this table: Table 2 Cognard classification of dural arteriovenous fistula However, the location of the CS and its venous connections limit the utility of the Cognard classification in this location. For example, a CS-DAVF with …