Introduction: Flow-diverting stents are increasingly being used for the treatment of complex intracranial aneurysms, but the indications for their use in lieu of traditional endovascular parent vessel occlusion (PVO) have yet to be precisely defined. The purpose of this study was to review the clinical and imaging outcomes of patients with intracranial aneurysms treated by PVO.

Methods: A total of 28 patients with intracranial aneurysms, treated by PVO between July 1992 and December 2009, were reviewed. Aneurysms arising from peripheral arteries were excluded. Clinical and imaging data were retrospectively analyzed from a prospectively maintained database.

Results: There were 28 patients with 28 aneurysms treated by PVO. Aneurysms of the anterior circulation presenting with mass effect (n=11) or discovered incidentally (n=1), and dissecting-type vertebrobasilar (VB) aneurysms presenting with SAH (n=6) faired the best with high obliteration rates (83.3% and 83.6%, respectively) and no permanent major ischemic complications. In contrast, VB aneurysms presenting with mass effect (n=7) demonstrated the lowest obliteration rate (57.1%), the highest rate of permanent major ischemic complications (28.6%), and a high mortality rate (28.6%).

Conclusions: PVO is a safe and effective treatment for complex intracranial aneurysms of the carotid artery and dissecting-type VB aneurysms presenting with SAH. In contrast, PVO for aneurysms of the VB circulation presenting with mass effect is less efficacious and associated with significant morbidity and mortality. It is hoped that flow diverters may represent a better treatment technique for these most difficult-to-treat lesions.

Patient Care: This research highlights the safety and effectiveness of traditional parent vessel occlusion for the treatment of large and giant anterior circulation aneurysms, e.g., cavernous aneurysms. The use of flow diverters should meet this high clinical benchmark. Alternatively, PVO is associated with significant morbidity and morality, with lower obliteration rates. It is hoped that flow diverters may represent a better treatment technique for these most difficult-to-treat lesions.

Learning Objectives: By the conclusion of this session, participants should be able to: (1) Discuss the indications for PVO in the treatment of complex intracranial aneurysms, and (2) Describe the complication and obliteration rates for this "destructive" procedure with relation to aneurysm location and pathogenesis.

References: Matouk CC, Kaderali Z, ter Brugge KG, Willinsky RA. Long-term clinical and imaging follow-up of complex intracranial aneurysms treated by endovascular parent vessel occlusion. American Journal of Neuroradiology. [Accepted - in pre-production].