Embolisation of cerebral arteriovenous malformations to assure successful subsequent radiosurgery

This study investigated the angiographic changes in embolised arteriovenous malformations (AVMs) pre- and post-embolisation and preradiosurgery to cla rify the usefulness of embolisation as a pretreatment for radiosurgery and the strategy of embolisation for the radiosurgical success. A total of 37 p atients with cerebral AVMs treated over a period of 4 years was investigate d. All the AVMs were embolised with N-butyl cyanoacrylate and 2 months late r they were treated by radiosurgery. The size of AVM nidus reduced just fol lowing the embolisation (mean 21.9 mi to 3.9 mi). The angiogram taken in pr eparation for radiosurgery showed a further size reduction in the nidus of 16 AVMs, no change in 10 and regrowth in 11. In all the cases where size wa s reduced, the nidus was densely packed, while ail the regrown AVMs were of the diffuse type. Five AVMs disappeared following radiosurgery, all of whi ch were size-reduction or no-change cases. In conclusion. to achieve succes s in subsequent radiosurgery, nidus embolisation and the occlusion of fistu lous and meningeal feeders are mandatory. Imprudent proximal feeder occlusi on and the use of embolic materials with a risk of recanalisation should be avoided to prevent regrowth of the nidus, which may lead to errors in plan ning the radiosurgery to follow. (C) 2000 Harcourt Publishers Ltd.