Vascular Anomalies and the Risk of Multiple Aneurysms Development and Bleeding

Abstract

<jats:p> The pathogenesis of aneurysmal subarachnoid hemorrhage is still debated and the prognosis remains severe, especially in multiple aneurysms, where the therapeutic management is complex. The aim of this study was to look for vascular anomalies and assess their relationship with aneurysm formation and bleeding in patients with multiple intracranial aneurysms. A prospective angiographical review was performed on 141 patients with multiple intracranial aneurysms seen from 1992 to 2000. Three hundred and fifty three aneurysms were studied. In 88% of the patients vascular anomalies were found. </jats:p><jats:p> The most common were: asymmetric caudal basilar fusion (43.2%), variations of the anterior communicating artery (AcoA) complex (31.2%), symmetric caudal basilar fusion (26.2%), antero-inferior cerebellar artery-postero-inferior cerebellar artery (AICA-PICA) (15.6%), extradural origin of the PICA (10.6%), cavernous origin of the ophthalmic artery or dorsal ophthalmic artery (dOPH) (3.5%). Some aneurysm locations were associated with a high rate of vascular anomalies, e.g.: posterior cerebral aneurysm with asymmetric caudal fusion, AcoA aneurysm with AcoA complex variation, basilar tip aneurysm with extradural PICA or symmetric caudal fusion, PI CA aneurysm with AICA-PICA, para-ophthalmic aneurysm with dOPH. These aneurysm locations bled proportionally more frequently when associated with the related vascular anomaly. In conclusion, these results suggest that vascular anomalies are associated with aneurysm development and bleeding. </jats:p>

Intradural Saccular Aneurysms Treated by Guglielmi Detachable Bare Coils at a Single Institution Between 1993 and 2005

“…The results corroborate previous findings that showed that patients with a single AA had a higher risk of subarachnoid hemorrhage than did patients harboring multiple AAs. 18 The total number of intradural saccular AAs in this patient cohort was 806, among which 320 were ruptured and treated, indicating that the majority of this type of AA do not bleed, at least within the observation time frame presented here.…”

Vascular variations associated with intracranial aneurysms

“…A variation of the circle of Willis was regarded as congenital abnormalities (5,22). Arteries with external diameter less than 1 mm and communicating arteries smaller than 0.5 mm were accepted as "hypoplastic" and the absence of the artery as "aplastic" (1,6,20,28).…”

“…arteriovenous malformation or cerebrovascular occlusive disease by changing the blood-flow pattern and increasing hemodynamic stress (3,4,7,12,13,15,23,26,29). There are some reports that have investigated the relationship between variations and aneurysm localization in cadaveric (12,20,28) and clinical studies (14,18,22,31).…”

Posterior inferior cerebellar artery with an extradural origin from the V3 segment: higher incidence on the nondominant vertebral artery

“…In other reports, PICA with an extradural origin is regarded as a risk factor for aneurysmal formation or occlusion. 9,11,16,24,27,29 Some authors argue that extradural PICAs are vulnerable to dissection because they tend to be forcefully stretched by neck motions or chiropractic procedures. 23,24,27 When encountering patients with subarachnoid hemorrhage in the posterior fossa with an unknown etiology, carefully consider involvement of an extradural PICA.…”