University of Oulu

Endovascular treatment of 467 consecutive intracranial aneurysms in Oulu University Hospital : angiographic and clinical results

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Author: Isokangas, Juha-Matti1,2
Organizations: 1University of Oulu, Faculty of Medicine, Department of Diagnostic Radiology
2Oulu University Hospital
Format: ebook
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 3.8 MB)
Persistent link:
Language: English
Published: 2006
Publish Date: 2006-12-22
Thesis type: Doctoral Dissertation
Defence Note: Academic dissertation to be presented, with the assent of the Faculty of Medicine of the University of Oulu, for public defence in Auditorium 7 of Oulu University Hospital, on January 12th, 2007, at 12 noon
Reviewer: Docent Leo Keski-Nisula
Docent Jaakko Rinne


The purpose of the study was to analyze the angiographic and clinical results of endovascularly treated intracranial aneurysms in Oulu University Hospital, Finland.

The study population consisted of 416 consecutive patients (467 aneurysms, 332 ruptured), who were referred for endovascular treatment of intracranial aneurysm(s) between December 1993 and July 2004. Technical failures were analyzed for an assesment of technical feasibility. Angiographic results were assessed using modified Raymond Classification. Clinical results were analyzed from patient files using the Glasgow Outcome Scale (GOS). Patient, aneurysm, and procedure related variables were tested with an intention to find the predictors of the angiographic and clinical outcome. The clinical effects on presenting symptoms were analyzed for a subgroup of patients with a symptomatic unruptured aneurysm (n = 30). The mean results on technical feasibility, complications, and angiographic results were separately assessed for three time periods (1993–1997, 1998–2000 and 2001–2004) to demonstrate potential significant changes in outcome.

Endovascular treatment of saccular aneurysms was technically feasible in 91.4% of the treatments. Initially, 25.7% of the aneurysms were completely occluded, 57.9% had a neck remnant, and 16.3% remained incompletely occluded. In follow-up, the rates for complete occlusions, neck remnants and incomplete occlusions were 37.6%, 49.7% and 12.7%, respectively. Small aneurysm size predicted complete aneurysm occlusion, while a wide aneurysm neck and location in the posterior circulation predicted incomplete occlusion. In follow-up (mean 38.2 months), 78.1% of the patients with a ruptured aneurysm and 92.3% of the patients with an unruptured aneurysm had resumed independent life (GOS 4–5). The predictors of good outcome were young age, good preprocedural clinical condition, small amount of blood in CT scan, and uncomplicated procedure. Ten of the treated aneurysms involved intracranial bleeding in follow-up, and the annual risk for bleeding after endovascular treatment was 0.95% among the patients with ruptured aneurysms and 0.33% among those with unruptured aneurysms. The risk of bleeding was associated with larger aneurysm size and lower occlusion grade. In the subgroup of symptomatic unruptured aneurysms, 53.4% of the patients showed either resolution or improvement of the symptoms after treatment. The rates of procedural complications, morbidity, and mortality were 16.5%, 6.7%, and 1.7%, respectively. The risk for procedural complications was higher when the balloon remodeling technique was used and lower in retreatments. Technical feasibility (85.6%, 90.6%, and 95.7%, respectively) and the percentage of complete occlusions (initially 16.5%, 23.0%, and 32.9%, respectively) were significantly improved by increased experience, while no statistical difference was detected in the total procedural complication rates (15.4%, 15.7%, and 18.3%, respectively) or the combined procedural morbidity and mortality rates (8.0%, 8.3%, and 9.1%, respectively). All six dissecting aneurysms treated with parent artery occlusion or the stent remodeling technique resulted in complete occlusions.

The present results confirmed endovascular treatment of intracranial aneurysms as a feasible, safe, and effective method in preventing further bleeding of aneurysms. Increased experience in a single center improved the feasibility of the treatment as well as the angiographic results.

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Series: Acta Universitatis Ouluensis. D, Medica
ISSN-E: 1796-2234
ISBN: 951-42-8311-2
ISBN Print: 951-42-8310-4
Issue: 906
Copyright information: © University of Oulu, 2006. This publication is copyrighted. You may download, display and print it for your own personal use. Commercial use is prohibited.