A PROPOSED ANGIOGRAPHIC CLASSIFICATION OF INTRACRANIAL ARTERIOVENOUS-FISTULAS AND MALFORMATIONS

We propose an angioarchitectural classification of intracranial vascul ar lesions as arteriovenous, arteriolovenous and arteriolovenulous fis tulae. In order to validate this classification, 99 intracranial arter iovenous lesions were reviewed in 98 patients. Arteriolovenulous fistu lae included 39 isolated brain arteriovenous malformations (AVMs) and 1 AVM associated with a giant arteriovenous fistula (AVF). Arterioveno us fistulae included 8 giant AVFs of the brain, 6 vein of Galen aneury sms and 10 direct caroticocavernous fistulae. Arteriolovenous fistulae included 1 isolated brain AVM, 4 vein of Galen aneurysms and 30 dural AVMs. The angioarchitectural classification has three advantages. It is simple and accurate, with no reference to the congenital or acquire d nature of the lesion. It allows separate identification of a special group, the arteriolovenous fistulae. It also indicates the endovascul ar approach: arteriolovenulous fistulae should be treated via the arte rial route only, while arteriovenous and arteriolovenous fistulae can be treated via transarterial or transvenous approaches.