Galenic pial arteriovenous fistulas: Angioarchitecture, clinical presentation, and therapeutic considerations.

Vein of Galen (VG) aneurysmal malformations (VGAMs) are complex vascular lesions. Their etiopathogenesis is extensively debated and remains poorly understood. Strictly speaking, true VGAMs are Galenic pial arteriovenous fistulas. They are believed to arise in utero and are contended to drain either into the true VG or the median prosencephalic vein of Markowski. Several classification systems have been proposed and are widely used. With the advent of endovascular therapy, precise understanding of the angioarchitecture is critical for management and therapeutic decision making. We review clinical presentation and diagnostic imaging findings, discussing angioarchitectural properties as they relate to treatment planning. Clin. Anat. 31:259-268, 2018. © 2017 Wiley Periodicals, Inc.