Endovascular treatment of distal intracranial aneurysms with Onyx 18/34

Surgical clipping and coil embolization of distally located intracranial aneurysms can be challenging. The goal of this study was to assess the feasibility, safety and efficacy of treatment of distal aneurysms with the liquid embolic agent Onyx 18/34.

Sixteen patients were treated with Onyx 18/34 for distally located aneurysms in our institution between March 2009 and September 2012. The technique consists of occluding the aneurysm as well as the parent vessel at the level of aneurysm with Onyx 18 or 34. Candidates for this treatment were patients with distal aneurysms including mycotic aneurysms, dissecting aneurysms, and pseudoaneurysms in which coiling was considered impossible.

Of the 16 patients, 12 presented with subarachnoid and/or intracerebral hemorrhage. Median aneurysm size was 4.6mm. Aneurysm locations were as follows: Posterior inferior cerebellar artery (n=5), distal anterior inferior cerebellar artery (n=3), distal pericallosal (n=3), distal anterior cerebral artery (n=3), lenticulostriate artery (n=1), and anterior ethmoidal artery (n=1). There were 4 mycotic aneurysms. Complete aneurysm obliteration was achieved in all 6 patients with available angiographic follow-up. There was only 1 (6.3%) symptomatic complication in the series. There were no instances of reflux or accidental migration of embolic material. Favorable outcomes were noted in 82% of patients at discharge. Two patients with mycotic aneurysms died from cardiac complications of endocarditis. No aneurysm recanalization or rehemorrhage were seen.

Parent vessel trapping with Onyx 18/34 offers a simple, safe, and effective means of achieving obliteration of distal challenging aneurysms.