A ruptured aneurysm at the basilar artery fenestration

Endovascular treatment of an aneurysm arising from the minor limb of an upper basilar artery fenestration: illustrative case

BACKGROUND

An aneurysm arising in an upper basilar artery (BA) fenestration is extremely rare. The authors reported a case involving successful endovascular treatment of an aneurysm arising from the minor limb of an upper BA fenestration.

OBSERVATIONS

A 65-year-old woman presented with an incidentally detected upper BA aneurysm arising from the minor limb of an upper BA fenestration. The irregularly shaped aneurysm was 6.0 × 2.7 mm in diameter, and the minor limb had several perforators. The aneurysm was nearly completely occluded with a catheter-assisted technique. The authors preserved both limbs of the BA fenestration. The postoperative course was uneventful, and the patient had an excellent clinical course with no neurological deficits or aneurysmal recanalization.

LESSONS

The case is the first report of an unruptured aneurysm arising at the minor limb of an upper BA fenestration. In this case, the authors preserved the minor limb with endovascular treatment. The authors believe catheter-assisted coil embolization to be a feasible endovascular technique in such cases.

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.

Fenestrations of the basilar artery demonstrated on magnetic resonance angiograms: an analysis of 212 cases

Fenestration of the basilar artery (BA) is a rare variant of the intracranial artery, well demonstrated in autopsy and angiographic studies. Some angiographic series show a high incidence of associated aneurysms at the basilar fenestration site. The purpose of this study is to report the incidence of BA fenestration, its configurations, associated aneurysms, and arterial anomalies in a large series of intracranial MR angiograms (MRAs). A total of 16,416 MRAs were retrospectively reviewed to identify the location, size and associated intracranial arterial anomalies of BA fenestrations. All images were obtained with the time-of-flight (TOF) technique. Of the 16,416 MRAs, 215 fenestrations were found in 212 cases (1.29%). Most fenestrations were located in the proximal BA. The average length of the fenestration was 4.6 mm; the largest was 15.6 mm. No aneurysm was found at the site of the fenestration. Thirteen aneurysms were found in nine cases at locations other than the BA: seven in the middle cerebral artery (MCA), one in the anterior cerebral artery (ACA), one in the anterior communicating artery (Acom), one in the vertebral artery (VA), one at the carotid siphon, and two at the internal carotid-posterior communicating artery (IC-PC). Arterial anomalies in other locations were found in 26 cases. BA fenestrations were found in 1.29% of the 16,416 cases studied. There were no aneurysms at the BA fenestration site. Aneurysms at the BA fenestration site may be an exceedingly rare phenomenon.

Endovascular treatment of basilar artery aneurysms associated with distal fenestration. A case report

SUMMARY

Segmental non-fusion of the basilar artery results from failed fusion of the neural arteries and from regression of the bridging arteries that connect the longitudinal arteries. This condition is associated with aneurysm formation in 7% of cases. Distally unfused arteries with associated aneurysms are very rare. We report on a case of successful endovascular treatment of an aneurysm of the distally unfused basilar trunk.

Segmental unfused basilar artery with kissing aneurysms: report of three cases and literature review

Basilar artery "fenestration" is the result of a failed fusion of the bilateral longitudinal neural arteries and can be associated with a saccular aneurysm, which typically arises at the proximal juncture of the unfused segment. "Kissing" aneurysms at this site, i.e. two aneurysms arising from the proximal junction of the unfused segment of the basilar artery pointing anteriorly and posteriorly are reported to be exceedingly rare. We present three patients with this rare condition, all of them being treated by endovascular techniques.

Coil embolization of "kissing aneurysms" associated with distal basilar artery fenestration

The authors present an extremely rare case of kissing aneurysms associated with fenestration of the distal basilar artery. The two aneurysms were successfully treated with endovascular coil embolization. We provide two-dimensional (2D) and three-dimensional (3D) angiographic features of the kissing aneurysms, and procedural details of coil embolization. To the best of our knowledge, this is the first demonstration of kissing aneurysms at the fenestrated distal basilar artery.

Ruptured aneurysm arising from a basilar artery fenestration and associated with a persistent primitive hypoglossal artery

✓ A 42-year-old woman experienced the sudden onset of a severe headache. Angiograms demonstrated a persistent primitive hypoglossal artery (PHA) originating from the internal carotid artery at the C-2 vertebral level. In addition, a fenestration at the PHA—basilar artery (BA) junction and an aneurysm at the proximal end of this fenestration were revealed. To perform endovascular embolization of the aneurysm, a microcatheter was introduced into the aneurysm sac via the PHA and two Guglielmi Detachable Coils were placed in the aneurysm. The patient's postoperative course was uneventful, and she was able to resume her normal life. Although many clinical cases have been reported in which a ruptured aneurysm was associated with a PHA or a BA fenestration, as far as the authors know there has been no case in the literature in which a ruptured aneurysm associated with both anomalies and no case in which endovascular embolization was used to treat a ruptured aneurysm associated with a PHA. This rare case is discussed and a review of the relevant literature is presented.

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.

Supraclinoid internal carotid artery fenestration with an associated aneurysm. Case report

The case of an aneurysm occurring at the site of fenestration of the supraclinoid portion of the left internal carotid artery (ICA) is reported. A 37-year-old woman presenting with subarachnoid hemorrhage was found to have bilateral ICA aneurysms at the level of the posterior communicating arteries (PCoA's). The patient underwent right-sided craniotomy with uneventful clipping of the right PCoA aneurysm, and attempted clip placement on the contralateral left ICA aneurysm. The follow-up angiogram revealed a residual dome on the left ICA aneurysm, which was noted to originate at the proximal end of a fenestration of the left supraclinoid ICA. This represents the third reported case of fenestration of the intracranial ICA associated with an aneurysm. Intracranial artery fenestrations and their embryological origins are also reviewed.

Aneurysm of the fenestrated basilar artery: report of two cases

This report describes two patients with fenestrated basilar artery aneurysms, and one of the patients underwent a postmortem examination. In our cases, the aneurysms arose at the proximal end of the fenestration, which involved the proximal third of the basilar artery. Subtraction angiography and oblique projections were essential in diagnosing the aneurysms. Complete neck clipping was successfully performed through a lateral suboccipital approach in the two cases. Technical aspects of neck clipping of the aneurysm of this unique location are discussed. Pathogenesis of these rare aneurysms is also discussed with clinical and histopathological data.

Cerebral arterial fenestrations associated with intracranial saccular aneurysms

Fenestrations of cerebral arteries other than the anterior communicating artery are rare congenital anomalies, which may be associated with saccular aneurysms. In such cases, the aneurysms may be located at the fenestration itself or may involve other intracranial vessels. This kind of association is not infrequently the cause of angiographic diagnostic problems, as well as surgical difficulties, and consequently needs to be well known to physicians. Four recent cases of rare fenestrations of cerebral arteries associated with intracranial aneurysms are reported in this study and discussed together with a review of the literature.

Duplication of the vertebro-basilar system

During the examination of 75 fixed brains and 2086 vertebral angiograms we encountered two cases of fenestration of the vertebral artery and two cases of partial duplication of the basilar artery. In the first case, an 81 year old male, there was fenestration, of the basilar artery at the union of the two vertebral arteries. The fenestration was 9mm long with no associated vascular disease. The other partial duplication of the basilar artery was observed in the upper portion of the artery in a 54 year old male patient investigated angiographically for subarachnoid haemorrhage. The fenestration of the third case was demonstrated in the intracranial part of the right vertebral artery of a 50 year old female patient during digital subtraction angiography for subarachnoid haemorrhage. In the fourth case, the fenestration was found angiographically at the atlanto-axial level in the extracranial portion of the left vertebral artery in a 37 year old female patient with subarachnoid haemorrhage from an arteriovenous malformation in the left cerebral hemisphere. The embryonic, histological and radiological implications of the duplication are discussed.

Cerebral arterial fenestration

Fenestration or duplication of a cerebral vessel is a rare congenital variation which most commonly involves the vertebral artery and is usually of no clinical significance. Fenestrations may have associated aneurysms remote to the anomaly or involving the proximal bifurcation of the fenestration. They may also be associated with other vascular malformations e.g. arteriovenous malformations and venous angiomas. Four fenestrated cerebral vessels and their angiographic appearances are reported in this study.

Aneurysms associated with fenestrated anterior cerebral arteries. Report of four cases and review of the literature

Four cases of aneurysms associated with a fenestrated anterior cerebral artery are presented. The combination of aneurysms and fenestration of the anterior cerebral artery is rare, and nine cases including ours have been reported. In all cases fenestrations were found within the distal two-thirds of the horizontal portion of the anterior cerebral artery. It may be presumed that fenestration of the anterior cerebral artery is the remnant of the plexiform anastomosis in the fetal stage, especially between the anterior cerebral artery and the primitive olfactory artery.

Saccular aneurysm associated with segmental duplication of the basilar artery. A morphological study

Saccular aneurysm associated with segmental duplication (also called "fenestration") of the basilar artery is an anomaly that results from an embryonic fault. Reports of the treatment of the aneurysmal component have only recently appeared in the neurosurgical literature, and little has been written on the morphology of this anomaly. This study answers the need for information about its structure to the extent permitted by the examination of a single specimen. The specimen was obtained at postmortem examination. A cast of its interior features was made with a synthetic rubber. After the cast was removed, the entire anomaly was serially sectioned for histological study. Defects in the wall of the basilar artery were seen microscopically at each end of the fenestration. At the extensive proximal defect, a saccular aneurysm arose that bulged into the window between the two limbs of the segmental duplication and also presented dorsally and ventrally. It had fatally ruptured. The manner in which the fenestration was formed by intraluminal septa was also revealed.

Ruptured anterior communicating artery aneurysms associated with fenestration of the anterior cerebral artery

Two patients with ruptured anterior communicating artery aneurysms associated with fenestration of the anterior cerebral artery are reported. In the literature, only 12 angiographic demonstrations of fenestration of the anterior cerebral artery have been reported. All fenestrations were limited to the distal half of the A1 portion, and seven of the 12 cases were associated with aneurysms. The high incidence of coexisting fenestration and aneurysm suggests that congenital factors may play a role in the pathogenesis of cerebral aneurysm.

Ruptured aneurysm at the anterior cerebral artery fenestration. Case report

✓ Fenestration of the anterior cerebral artery is rare. The authors describe a case of a ruptured aneurysm arising from the proximal end of a fenestration of the anterior cerebral artery. The lesion was demonstrated by angiography and confirmed at surgery.