Basilar Artery Fenestration Research Articles

Neuroradiological Analysis of 23 Cases of Basilar Artery Fenestration Based on 2280 Cases of MR Angiographies

Basilar artery (BA) fenestrations are the most frequently observed variant of the cerebral arteries. We examined the magnetic resonance (MR) angiographic incidence, location, characteristic configuration of BA fenestration and associated vascular disease. From April 2004 to September 2004, a total of 2280 cranial MR angiographies were performed at our institution. Twenty-three BA fenestrations (1.0%) were detected on MRA. There were 13 males and ten females in this group and mean age was 57.6 years old. Three cases of these fenestration group are suffered with atherothrombic infarction in the territory of vertebro-basilar system. Seven of 23 cases (30%) were associated with intracranial aneurysm. Of those four cases, aneurysms were located at anterior circulation. Of those three cases, the aneurysms were associated with BA fenestration. Since saccular aneurysms are reported to arise frequently at BA fenestration, knowledge and recognition of fenestration are useful and important in the interpretation of cerebral MR angiography.

Extreme Duplication-type, Nonseparated Fenestration of the Basilar Artery in a Patient with Pontine Infarction: Confirmation with Virtual Arterial Endoscopy

We present a case of a 55-year-old woman with pontine infarction and fenestration of the basilar artery that was demonstrated using virtual endoscopy. The patient had motor weakness of the right side with sudden onset. Diffusion- and T2-weighted MR images revealed high signal intensities in the left pontine regions, and an MR angiographic examination showed the double-lumen sign of the basilar artery. An extensive duplication-type, nonseparated fenestration of the basilar artery was diagnosed by virtual endoscopy and craniocaudal communications with discrete openings were observed. We report a case of a patient with basilar artery fenestration and associated brainstem infarction.

Endovascular Treatment of Ruptured Aneurysms Associated With Fenestrated Basilar Artery-Two Case Reports-

Two patients with ruptured aneurysm associated with fenestrated basilar artery (BA) were treated using the endovascular approach. Angiography showed these patients had different types of BA bifurcation. One type had two points of bifurcation and a bridging artery in the BA fenestration, with the aneurysm at the bifurcation of the right loop of the fenestration. The aneurysm had different appearances on right and left vertebral angiograms. The other type had only one point of bifurcation, and the appearance of this aneurysm was similar on both angiograms. To ensure successful embolization, bilateral vertebral angiography should be performed for complete assessment of the morphological characteristics of aneurysm associated with fenestrated BA.

進行性に増大する後頭蓋か血栓性動脈りゅうに対する外科治療

We report 8 patients with growing thrombosed aneurysms in the posterior fossa, all of which seriously compressed the brain stem or medulla oblongata. Angiographically, 7 of 8 cases were categorized as so-called fusiform or dolichoectatic aneurysms and 1 case was a saccular aneurysm at the basilar artery fenestration. The unilateral vertebral artery was involved in 4 cases, the basilar artery in 2 cases, and the vertebro-basilar artery in 2 cases. The 7 males and 1 female ranged in age from 38 to 64 years (mean: 48.8 years). Hypertension and hypercholesterolemia were noted in all the patients. The 3 large aneurysms at the vertebral artery were excised after occipital artery (OA)—posterior inferior cerebellar artery (PICA) anastomosis in 2 cases and endarterectomy of the contralateral vertebral artery stenosis in 1 case. The bypass functioned well and patients recovered well. The 4 giant aneurysms of the vertebral and/or basilar artery were treated by a Hunterian ligation and high-flow bypass using the radial artery graft between the extracranial vertebral artery and the posterior cerebral artery (PCA). An inverted flow direction and termination of the aneurysmal sac led to the stagnation of the blood stream in the aneurysmal dome. However thromboembolism from intra-aneurysmal clot induced serious brain stem infarction in 3 cases, and aneurysmal growth after surgery was noted in all cases. To prevent intra-aneurysmal clotting in the acute phase, strong heparinization is essential and a second step to excise the growing aneurysm in the chronic phase is also required.

Endovascular treatment of kissing aneurysms at the fenestrated basilar artery: Case report with literature review

BACKGROUND Basilar artery fenestrations are most commonly located in the proximal basilar trunk close to the vertebrobasilar junction and may harbor saccular aneurysms. Surgical treatment of such aneurysms has been reported in several cases previously, despite the difficulty of the surgical approach. Endovascular treatment may provide a more convenient treatment alternative in such cases. This case is also interesting in that two discrete aneurysms arise from each limb of the fenestration. CASE REPORT A 20-year-old man presented with acute subarachnoid hemorrhage. He had two kissing aneurysms at the fenestrated proximal basilar artery as demonstrated by MRA and selective angiography. The two aneurysms were successfully treated with GDCs via the contralateral vertebral arteries. One-year control angiogram showed stable occlusion. CONCLUSION Aneurysms at the fenestrated basilar artery may be effectively treated with endovascular coil occlusion. The occurrence of multiplicity and the treatment alternatives are discussed, with relevant literature review.

瘤内塞栓療法によって治療した脳底動脈窓形成部破裂動脈瘤の1例

瘤内塞栓療法によって治療した脳底動脈窓形成部破裂動脈瘤の1例

Basilar Artery Fenestration Aneurysms Treated with Guglielmi Detachable Coils

Four patients with basilar artery fenestration aneurysms at the vertebra basilar junction were admitted after subarachnoid haemorrhage. In two of them attempted surgery failed. Subsequently, all four were embolised with Guglielmi Detachable Coils (GDC), three of them in the acute phase. In one case the initial embolisation was incomplete, but follow-up angiography demonstrated spontaneous total occlusion. In another, partial reopening was treated with further embolisation. Three patients recovered completely after treatment. One patient still has deficits related to surgery of an accompanying aneurysm at the middle cerebral artery. He is clinically improving but still not back at work. In two cases the fenestration was combined with a hypoplastic upper vertebral artery on one side. A hypoplastic veretebral artery on one side may frequently be part of the developmental anomaly of basilar fenestration aneurysms. The anatomical configuration and location of these aneurysms is such that their true nature is sometimes difficult to disclose at cerebral angiography and is only realised during embolisation. Treatment with GDC coils seems superior to surgery in basilar artery fenestration aneurysms.

Moyamoya with arterial anomalies: relevance to pathogenesis.

We report five patients with moyamoya associated with arterial anomalies, including five aneurysms, one with ectasia of the parent artery, a basilar artery fenestration and an arteriovenous malformation. Possible pathogenetic factors for moyamoya are discussed, and a prenatal origin is suggested.

A ruptured aneurysm at the distal end of the basilar artery fenestration associated with multiple fenestrations of the vertebrobasilar system: Case report

An aneurysm at the fenestrated basilar artery usually arises at the proximal end of the fenestration, with few exceptions. We failed to reveal any case of aneurysm at this site associated with multiple fenestrations of the vertebrobasilar system. This 62-year-old male was admitted to our hospital 1 day after a sudden onset of headache. CT scan showed subarachnoid hemorrhage, and angiogram revealed an aneurysm at the distal end of the fenestrated basilar artery in association with two other fenestrations of the vertebrobasilar system. The limb of the basilar artery fenestration was trapped tightly with one clip through the transcondylar approach. Postoperative course was uneventful, and postoperative angiogram showed complete disappearance of the aneurysm. An extremely rare case of an aneurysm at the distal end of the fenestrated basilar artery in association with multiple fenestrations of the vertebrobasilar system is reported. The coexistence of vertebral artery fenestration and the fenestration of the vertebrobasilar junction may give a clue to the mechanism of occurrence of basilar artery fenestration.

Basilar artery fenestration in association with aneurysms of the posterior cerebral circulation.

We reviewed all patients over a 3-year period with documented aneurysms of the posterior cerebral circulation, and re-examined the angiograms of 103 patients. There were 9 cases of fenestration of the basilar artery, all associated with aneurysms of the basilar artery. In 6, the aneurysm arose at the site of the fenestration. We believe that the presence of a fenestration predisposes to aneurysm formation, due to the combination of the resulting alteration in flow characteristics and the presence of a defect in the media of the vessel.

窓形成を伴った椎骨動脈合流部のlarge動脈瘤の治療例

We highlighted 2 cases of radical clipping of large aneurysms that were seen in the vertebrobasilar junction accompanied by a vascular deformity, consisting of fenestration of the split basilar artery at the origin of the basilar artery. Information concerning the inner and outer surface of the aneurysm were obtained pre-operatively from neuroradiographic studies by 3-D CT and 3-D CT endoscopy of the position of the neck, parent vessels of the vertebral arteries on both side, basilar artery and split basilar artery as well as its branches. The neck had a broad base in both cases. The height of the neck extended to the internal acoustic meatus, and it was possible to expose the periphery of the aneurysmal neck with an anterior transpetrosal approach. Based on the size of the aneurysm which was placed on the anterior surface of the brain stem, clipping or arterial reconstruction were performed in the first case under cover of barbiturates and deep hypothermia extracorporeal circulation, and in the second case in a state of circulatory arrest. The following provides a report of these 2 cases along with other cases treated so far.

Vertebrobasilar junction fenestration associated with dissecting aneurysm of intracranial vertebral artery.

Vertebrobasilar junction fenestration is considered to be a subtype of fenestration of the proximal basilar artery, which has been described only in autopsy cases. The fenestration associated with a dissecting vertebral aneurysm is extremely rare. A 47-year-old man presented with subarachnoid hemorrhage. The four-vessel angiogram showed a fusiform dilatation with an intimal flap of the left vertebral artery distal to the origin of the posterior inferior cerebellar artery and a fenestration at the vertebrobasilar junction, in which a small limb of the fenestration arising from the distal portion of the left vertebral artery bridged the proximal basilar trunk, while another limb had a large diameter showing the same diameter as the basilar artery. The dissecting aneurysm was treated with body clipping by directly clipping the ruptured portion of the aneurysm via a suboccipital approach in an early operation 48 hours after the ictus. The patient had a good recovery and returned to his work. He is well at a 5-year follow-up. The relevant angiographic features of the vertebrobasilar junction fenestration and the surgical treatment of such associated aneurysms are discussed.

BASILAR ARTERY FENESTRATION WITH THROMBOSIS

BASILAR ARTERY FENESTRATION WITH THROMBOSIS