Revascularization of brain arteriovenous malformations after embolization with brucrylate

Between 1984 and 1988, 52 brain arteriovenous malformations (AVMs) were embolized in the Radiology Department of the Toronto Western Hospital. 9 were localized in the occipital lobe. There was angiographic follow-up ranging from one to four years. Two embolized AMVs, both occipital, showed revascularisation at 6 months and two years respectively. In one case the embolization had resulted in a complete obliteration of the AVM. In the other, the nidus was reduced by 95%. It is suggested that the occipital lobe, because of its rich vascularity, is more prone than other parts of the brain to produce intense collateralization leading indirectly to resupply of embolized AVMs. Existence of these collaterals may also explain the rarity of visual defects in occipital AVMs. These cases confirm the need for post therapeutic angiographic controls to assess the stability of the results obtain. (orig.)