Aneurysm of the fenestrated basilar artery: report of two cases

Management of basilar fenestration aneurysms: a systematic review with an illustrative case report

BACKGROUND

Basilar artery (BA) fenestration aneurysm (BAFA) is a rare phenomenon commonly accompanying other aneurysms. Treatment is challenging, and few cases have been reported. This review investigated the management outcomes of BAFAs.

METHODS

Publication databases were searched to identify studies evaluating outcomes of endovascular treatment (EVT) and microsurgical treatment of BAFAs from inception through 2021. Outcomes (clinical, angiographic, postoperative complications, and retreatment rates) were collected and analyzed. The authors present their case of a patient treated for a BAFA.

RESULTS

Including the authors' case, 184 patients with 209 BAFAs were reported in 68 studies. Most patients (130/175; 74.3%) presented with ruptured aneurysms, most commonly involving the proximal segment of the BA. Most BAFAs were small (52/103, 50.5%) and saccular (119/143, 83.2%). Most patients underwent EVT (143/184, 77.7%); the rest underwent microsurgery. Postoperative complications after EVT occurred in 10 (8.3%) of 120 patients, with 4 of the 10 experiencing strokes. At clinical follow-up, most EVT patients (74/86, 86.0%) showed good outcomes; 3.9% (2/51) had died. Most aneurysms managed with EVT (56/73, 76.7%) showed complete occlusion at follow-up; 7.3% (8/109) were retreated. Postoperative complications occurred in 62.2% (23/37) of microsurgical patients; 5 (21.7%) of the 23 experienced strokes. All patients showed good clinical outcomes at follow-up. Most aneurysms (22/28, 78.6%) treated microsurgically showed complete occlusion at angiographic follow-up, with no retreatment required.

CONCLUSION

BAFAs are often symptomatic; thus, treatment is challenging. By the 2000s, treatment had moved from microsurgical to endovascular modalities, with good clinical and angiographic outcomes.

Cerebral arterial fenestrations

Arterial fenestrations are an anatomic variant with indeterminate significance. Given the controversy surrounding fenestrations we sought their prevalence within our practice along with their association with other cerebrovascular anomalies. We retrospectively reviewed 10,927 patients undergoing digital subtraction angiography between 1992 and 2011. Dictated reports were searched for the terms "fenestration" or "fenestrated" with images reviewed for relevance, yielding 228 unique cases. A Medline database search from February 1964 to January 2013 generated 304 citations, 127 cases of which were selected for analysis. Cerebral arterial fenestrations were identified in 228 patients (2.1%). At least one aneurysm was noted in 60.5% of patients, with an aneurysm arising from the fenestration in 19.6% of patients. Aneurysmal subarachnoid hemorrhage or non-aneurysmal subarachnoid hemorrhage were present in 60.1% and 15.8%, respectively. For the subset of patients with an aneurysm arising directly from a fenestration relative to those patients with an aneurysm not immediately associated with a fenestration, the prevalence of aneurysmal subarachnoid hemorrhage was 66.7% vs. 58.6% (p = 0.58). Fenestrations were more often within the posterior circulation (73.2%) than the anterior circulation (24.6%), though there was no difference in the prevalence of aneurysms within these groups (61.1% vs. 60.7%, p = 1.0). Cerebral arterial fenestrations are an anatomic variant more often manifesting at the anterior communicating arterial complex and basilar artery and with no definite pathological relationship with aneurysms.

Endovascular management of multiple cerebral aneurysms in acute subarachnoid hemorrhage associated with fenestrated basilar artery. A case report and literature review

Aneurysms arising from the fenestration of the basilar artery are rare. We describe a patient with two aneurysms originating from the fenestration of the basilar artery and the middle cerebral artery. Endovascular treatment with detachable platinum coils was performed, and two aneurysms were cured at the same time. Endovascular treatment of aneurysms associated with fenestrated basilar artery appears to offer advantages over traditional open surgical techniques.

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

SUMMARY

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.

Ruptured saccular aneurysm of distal vertebral artery fenestration managed with Guglielmi detachable coils and intraventricular tissue plasminogen activator

BACKGROUND

Aneurysms associated with vertebrobasilar fenestrations are uncommon. We report on an unusual presentation of such aneurysm with a dedicated arterial pedicle, manifesting with significant intraventricular hemorrhage. Equally important, the aneurysm was managed in a multidisciplinary fashion, which, we think, greatly contributed to a good outcome.

CASE DESCRIPTION

A 55-year-old man presented in good condition after subarachnoid and massive intraventricular hemorrhage. The aneurysm location and the extent of intraventricular hemorrhage both presented concerns regarding treatment approach. The aneurysm was first treated with transarterial coil obliteration, and intraventricular tissue plasminogen activator (tPA) infusion was given, with rapid resolution of evolving hydrocephalus. The patient had an excellent outcome.

CONCLUSION

To our knowledge, this is the first report of a vertebrobasilar fenestration saccular aneurysm with a dedicated pedicle projecting toward the foramen of Magendie with significant intraventricular hemorrhage. In addition, this patient was successfully managed with endovascular obliteration and intraventricular tPA infusion.

Ruptured vertebrobasilar junction aneurysm associated with basilar artery fenestration

A case of a ruptured saccular aneurysm arising from the proximal portion of a partially duplicated basilar artery in a 36-year-old woman is reported. CT and lumbar puncture confirmed subarachnoid haemorrhage. Cerebral angiography detected a vertebrobasilar junction aneurysm associated with basilar artery fenestration. The patient underwent successful clipping and coating of the aneurysm by a right lateral suboccipital osteoclastic approach. Embryological development, pathogenesis, diagnostic and therapeutic difficulties of this vascular malformation are discussed in this report.

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

BACKGROUND

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.

CASE REPORT

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.

CONCLUSION

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.