A proposed classification for spinal and cranial dural arteriovenous fistulous malformations and implications for treatment

Abstract

A classification is proposed that unifies and organizes spinal and cranial dural arteriovenous fistulous malformations (AVFMs) into three types based upon their anatomical similarities. Type I dural AVFMs drain directly into dural venous sinuses or meningeal veins. Type II malformations drain into dural sinuses or meningeal veins but also have retrograde drainage into subarachnoid veins. Type III malformations drain into subarachnoid veins and do not have dural sinus or meningeal venous drainage. The arterial supply in each of these three types is derived from meningeal arteries. The anatomical basis of the proposed classification is presented with several cases that illustrate the three types of dural AVFMs. A rationale for the treatment of spinal and cranial dural AVFMs according to their anatomical characteristics is discussed.

Venous congestive myelopathy: a mimic of neoplasia

“…[24][25][26] The most recent classifications of spinal arteriovenous fistulas have emphasized the pathological anatomy of the vascular channels, encompassing all surgical vascular lesions and providing a clear rationale to guide treatment. 12,[27][28][29] We find particularly simple and useful the distinction of arteriovenous fistulas as dural, intradural (perimedullary and intramedullary), and extradural based on the location of the fistula. 26 The most common of these, spinal dural arteriovenous fistula, as well as the less frequently encountered perimedullary and epidural fistula all can cause a progressive myelopathy.…”

Evaluation of Intracranial Dural Arteriovenous Fistulas: Comparison of Unenhanced 3T 3D Time-of-flight MR Angiography with Digital Subtraction Angiography

“…Venous drainage directly into the dural venous sinus was recorded as Type 1, into the dural venous sinus with cortical venous reflux, as Type 2, and directly into the subarachnoid veins (cortical venous reflux only), as Type 3, according to the classification of Borden and associates. 20 The readers were cognizant of the possibility of false-positive intracranial MRA findings.…”

Arterial Onyx Embolisation of Intracranial DAVFs with Cortical Venous Drainage

“…Embolisation of particles has proven to be of limited use in reducing flow rate, but may have only a temporary result and is generally not curative. Surgery and radiotherapy have also been employed for the treatment of these lesions with varying success, with or without adjuvant arterial embolisation with nBCA [7][8][9]5 , however radiotherapy is not immediately curative, requiring a period of some months for the fistula to close after treatment, during which time it is not protected from haemorrhage.…”

“…Radiographic grading systems are therefore based around this correlation between venous drainage and pattern of clinical behaviour. 1,5 Treatment of DAVFs has also been similarly stratified. Lesions without cortical venous drainage may be treated conservatively.…”