Background and purpose:limited data exist to guide proper patient selection for preventive treatment of unruptured cerebral aneurysms. Cerebral aneurysms have been associated with anomalies of arterial segments that are forming the brain arterial circle of Willis but whether this association is also related to aneurysm rupture is not known. The occurrence of cerebral aneurysm rupture when a circle of Willis anomaly was present or absent was compared.
Material and methods: we have performed this study on a number of 312 cases, of which 87 were dissections, 22 dissection followed by plastic injection, 135 magnetic resonance angiography (MRA), 75 computer tomography angiography (CTA), 40 digital subtraction angiographies (DSA), 30 in vivo (intraoperatory) observation. Brain vascular imaging was reviewed for aneurysm size, morphology and presence of anterior cerebral artery anomalies.
Results: we divided the study group in 2 cohorts, one control group of 272 cases, in which we have study the anatomical variants occurrence and aneurysm occurrence in general population and another included 45 patients admitted thru emergency room for subarachnoid hemorrhage, of those 38 were ruptured aneurysm of anterior communicating artery (ACoA). Mean aneurysm size was 8.9 mm. An anterior cerebral artery anomaly was identified in 31 cases (81.5%). Multivariate analysis revealed a higher risk of aneurysm rupture when an anterior cerebral artery was present.
Conclusions: this study shows that anterior cerebral artery anomalies are more commonly found in ruptured as opposed to unruptured ACoA aneurysms. The presence of an ACA anomaly may be an important characteristic for selecting patients for preventive aneurysm treatment.
If the inline PDF is not rendering correctly, you can download the PDF file here.
1. Wiebers D.O. Whisnant J.P. & Huston J 3rd et al (2003). Unruptured intracranial aneurysms: natural history clinical outcome and risks of surgical and endovascular treatment. Lancet. 362 103-10.
2. Bederson J.B. Awad I.A. Wiebers D.O. et al. (2000). Recommendations for the management of patients with unruptured intracranial aneurysms: a statement for healthcare professionals from the Stroke Council of the American Heart Association. Stroke. 39(1) 2742-50.
3. Rinkel G.J. Djibuti M. & Algra A. et al. (1998). Prevalence and risk of rupture of intracranial aneurysms: a systematic review. Stroke.29251-6
4. Forget T.R. Jr Benitez R. & Veznedaroglu E. et al. (2001) - A review of size and location of ruptured intracranial aneurysms. Neurosurgery. 49 1322-5
5. Kapoor K. Singh B. & Dewan L.I. (2008) - Variations in the configuration of the circle of Willis. Anat Sci Int. 83 96-106.
6. Lazzaro M.A. Ouyang B. & Chen M. (2011). The role of circle of Willis anomalies in cerebral aneurysm rupture. J NeuroIntervent Surg. doi:10.1136/jnis.2010.004358
7. Tanaka H. Fujita N. & Enoki T. et al. (2006). Relationship between variations in the circle of Willis and flow rates in internal carotid and basilar arteries determined by means of magnetic resonance imaging with semiautomated lumen segmentation: reference data from 125 healthy volunteers. AJNR Am J Neuroradiol. 27 1770-5.
8. Ingebrigtsen T. Morgan M.K. & Faulder K. et al. (2004) - Bifurcation geometry and the presence of cerebral artery aneurysms. J Neurosurg. 101 108-13.
9. Rhoton A.L. Jr. (2002). Aneurysms. Neurosurgery. 51(4 Suppl) S121-58.
10. Bor A.S. Velthuis B.K. & Majoie C.B. et al. (2008). Configuration of intracranial arteries and development of aneurysms: a follow-up study. Neurology. 70 700-5.
11. de Rooij N.K. Velthuis B.K. & Algra A. et al. (2009). Configuration of the circle of Willis direction of flow and shape of the aneurysm as risk factors for rupture of intracranial aneurysms. J Neurol. 256 45-50.
12. Stojanovic N. Stefanovic I. & Randjelovic S. et al. (2009). Presence of anatomical variations of the circle of Willis in patients undergoing surgical treatment for ruptured intracranial aneurysms. Vojnosanit Pregl. 66 711-17