ABSTRACT
BACKGROUND AND PURPOSE: Previous studies have described a correlation between variants of the circle of Willis and pathological findings, such as cerebrovascular diseases. Moreover, anatomic variations of the anterior cerebral artery (ACA) seem to correspond to the prevalence of aneurysms in the anterior communicating artery (ACoA). The aim of this study was to assess the prevalence of aneurysms in patients with anatomical/morphological variations of the circle of Willis. METHODS: We retrospectively analyzed 223 patients who underwent cerebral angiography between January 2002 and December 2010 for aneurysm of the ACoA. Diagnostic imaging was reviewed and statistically evaluated to detect circle of Willis anomalies, aneurysm size, and rupture. 204 patients with an unrelated diagnosis served as the control group. RESULTS: Variations of the A1 segment occurred significantly more frequently in the aneurysm group than in the control group. Mean aneurysm size in patients with grades I and III hypoplasia or aplasia was 6.58 mm whereas in patients with grade II hypoplasia it was 7.76 mm. CONCLUSIONS: We found that variations in the A1 segment of the ACAs are correlated with a higher prevalence of ACoA aneurysms compared with patients with a symmetric circle of Willis.
Subject(s)
Aneurysm, Ruptured/diagnostic imaging , Circle of Willis/diagnostic imaging , Intracranial Aneurysm/diagnostic imaging , Aged , Aneurysm, Ruptured/etiology , Anterior Cerebral Artery/abnormalities , Anterior Cerebral Artery/anatomy & histology , Anterior Cerebral Artery/diagnostic imaging , Circle of Willis/abnormalities , Circle of Willis/anatomy & histology , Female , Humans , Intracranial Aneurysm/etiology , Male , Middle Aged , Prevalence , Radiography , Retrospective StudiesABSTRACT
BACKGROUND AND OBJECT: Cranial dural arteriovenous fistulas are commonly treated using an endovascular method. In comparison to intracerebral arteriovenous malformations, it is important to reach the venous part of these malformations to maintain a complete occlusion. Therefore, often the venous side is totally occluded using coils and∕or glue. PATIENT AND METHODS: We describe a patient with an initially Type IIab (Cognard classification) left occipital cranial fistula. The patient suffered from an intense pulsate tinnitus. Therefore, the first embolization was performed using an approach via the dilated left middle meningeal artery using Onyx. The shunt of the fistula was reduced significantly but total occlusion was impossible. Therefore, the venous approach was used. Over a guiding catheter in the sigmoid sinus, the venous side of the fistula could be reached with a microcatheter. This part of the fistula was then completely occluded using coated and bare coils, without occluding the adjacent sinus. Control angiography of all previous feeders showed a complete occlusion of the fistula (used classification: Cognard). RESULTS: The fistula was entirely occluded. The patient's outcome was excellent. The patient did not develop any symptoms and no complication occurred due to the treatment. CONCLUSIONS: Direct occlusion of the venous part of an arteriovenous cranial fistula can be an option before an occlusion of the sinus has to be performed. This approach can lead to reduction of risk during the endovascular procedure and risk reduction in long-term follow-up.
