Angiographic Classification: Arteriovenous Malformation and Venous Malformation

Abstract

Angiography is the gold standard of confirmative diagnosis as well as therapeutic tools in arteriovenous malformation (AVM). Typically, artery angiography in AVM shows feeding artery, nidus, and early draining veins. These malformed vascular structures can be imaged through the full-shot arteriography, but it is hard to separate individual vascular component only with a single overall angiographic image. Angiographic findings of AVM are totally different in every single patient, and the malformed vasculature is very complex to figure out the detailed vascular connection at a glance. Not infrequently, untrained physician cannot discriminate even between the artery and vein on angiography because the vessels are numerous, tortuous, and overlapped with each other. Therefore, systematized angiographic classification for the AVM seldom appears in the medical literatures. Complex vascular connection in AVM can be imaged better with selective arteriography, and sometimes direct puncture arteriography is helpful for understanding detailed vascular connection and hemodynamic status of AVM components vessel. Without understanding vascular anatomy and its hemodynamic interaction of the malformed vessels in the AVM, adequate treatment plan is difficult to make. As for the endovascular treatment, some type of AVM responds to treatment dramatically, but some AVM is hard to relieve even with repetitive procedures. Therefore, types and patterns of different AVMs have been required to be classified systematically to correlate with the treatment response.