Angiographic follow-up of large cerebral AVMs incompletely embolized with isobutyl-2-cyanoacrylate

Abstract

This study evaluated the long-term angiographic results in large cerebral arteriovenous malformations (AVMs) partially embolized with isobutyl-2-cyanoacrylate. Preembolization, immediate postembolization, and long-term follow-up angiograms were performed in 30 large, partially embolized brain AVMs. Particular attention was paid to the relative size of the residual AVM nidus and the embolized arterial feeders, to recruitment of new feeders, to the size of residual draining veins, and to the speed of arteriovenous shunt. Nine cases with less than 50% AVM nidus obliteration showed no significant morphologic changes. In 18 cases with 50-75% obliteration of the AVM nidus, 11 (61.1%) showed no significant changes, six (33.3%) showed enlargement of the AVM nidus, and one (5.5%) evolved to complete angiographic obliteration. In three cases with 75-99% AVM nidus obliteration, one remained unchanged, one showed an increase in the size of the AVM nidus, and one evolved to complete obliteration. Evaluation by plain film, CT, and cerebral angiography of the isobutyl-2-cyanoacrylate deposits showed that when the polymer was positioned predominantly in arterial feeders there was invariably reconstitution of the AVM nidus through leptomeningeal, deep medullary, and/or dural collaterals. This phenomenon did not occur when the isobutyl-2-cyanoacrylate was deposited mainly in the AVM nidus.