A retrospective analysis of endovascular therapy of 100 brain aneurysms in 95 patients is reported. 63.8 % of patients with aneurysms in anterior circulation (n = 58) suffered from bleeding and 84 % in posterior circulation (n = 37) had subarachnoid hemorrhage (SAH). Aneurysms were offered from several centers when neurosurgical treatment was believed to be unpossible or risky due to anatomical reasons or poor clinical status of a patient. Endovascular therapy was performed by selective filling of the aneurysm sac with detachable coils. In 31.7 % carotid and 9.4 % vertebrobasilar aneurysms the parent artery was closed together with the aneurysm. Stability of sac occlusion was followed by skull plain films and magnetic resonance angiography. The therapy was not technically successful in 8 aneurysms and patients (technical success rate 92 %). Three patients died during 30 days due to treatment complication.Five patients remained with permanent deficit being partly or fully dependent. One of these patients died 12 months later. Another fully dependent due to vasospasms died 6 months later. Significant morbidity and mortality caused directly by therapy was 8.4 %.During mean follow-up of 36 months 15.6 % of aneurysms were indicated to reembolization of recurrent aneurysm cavity and another 20 % aneurysms could not be fully embolized or a secondary aneurysm cavity occurred which was not indicated to reembolization. So partial or unstable aneurysm occlusion was observed during follow-up in 35.6 % of all treated aneurysms. Recurrent SAH occurred in 2.2 % twelve hours after embolization followed by neurological deficit (Rankin 3) andin1 year after reembolization in the second case. This patient remained without deficit. The most important problem of endovascular selective embolization of brain aneurysms is poor long-term stability of aneurysm sac occlusion which frequence increases with size of the sac and neck and the intraluminal thrombus presence before the treatment. On the other hand the parent artery occlusion, usually done in large aneurysms, when collateral flow is sufficient, seems to be stable. On the base of current literature small aneurysms with narrow neck should be primarily considered to endovascular therapy since in these cases there is high probability of stable long-term occlusion. The neurosurgeons offered to endovascular therapy frequently the aneurysms of the vertebrobasilar circulation (37 % in our series) and large aneurysms of the internal carotid artery (19 % in our series).

        Key words: cerebral aneurysm, endovascular embolization, subarachnoid hemorrhage