Fenestration of the supraclinoid internal carotid artery associated with aneurysm and ischemic stroke

Imaging and blood flow characteristics of cerebrovascular fenestration malformation and its relationship with the occurrence of ischemic cerebrovascular disease

OBJECTIVE

To explore the imaging and transcranial Doppler cerebral blood flow characteristics of cerebrovascular fenestration malformation and its relationship with the occurrence of ischemic cerebrovascular disease.

METHODS

A retrospective analysis was conducted on the imaging data of 194 patients with cerebrovascular fenestration malformation who visited the Heyuan People's Hospital from July 2021 to July 2023. The location and morphology of the fenestration malformation blood vessels as well as the presence of other cerebrovascular diseases were analyzed. Transcranial Doppler cerebral blood flow detection data of patients with cerebral infarction and those with basilar artery fenestration malformation were also analyzed.

RESULTS

A total of 194 patients with cerebral vascular fenestration malformation were found. Among the artery fenestration malformation, basilar artery fenestration was the most common, accounting for 46.08% (94/194). 61 patients (31.44%) had other vascular malformations, 97 patients (50%) had cerebral infarction, of which 30 were cerebral infarction in the fenestrated artery supply area. 28 patients with cerebral infarction in the fenestrated artery supply area received standardized antiplatelet, lipid-lowering and plaque-stabilizing medication treatment. During the follow-up period, these patients did not experience any symptoms of cerebral infarction or transient ischemic attack again. There were no differences in peak systolic flow velocity and end diastolic flow velocity, pulsatility index and resistance index between the ischemic stroke group and the no ischemic stroke group in patients with basal artery fenestration malformation (P > 0.05).

CONCLUSION

Cerebrovascular fenestration malformation is most common in the basilar artery. Cerebrovascular fenestration malformation may also be associated with other cerebrovascular malformations. Standardized antiplatelet and statin lipid-lowering and plaque-stabilizing drugs are suitable for patients with cerebral infarction complicated with fenestration malformation. The relationship between cerebral blood flow changes in basilar artery fenestration malformation and the occurrence of ischemic stroke may not be significant.

Endovascular treatment of a supraclinoid internal carotid artery fenestration aneurysm: A case report and literature review

Supraclinoid internal carotid artery (ICA) fenestration aneurysm is rare. Except for open surgery, endovascular treatment (EVT) is considered an alternative for such an aneurysm. However, experience with this procedure is lacking. Therefore, we reported such a case. A 61-year-old woman suffered subarachnoid hemorrhage. Digital subtracted angiography (DSA) showed bilateral middle cerebral artery (MCA) aneurysms and a saccular aneurysm associated with fenestration of the supraclinoid ICA. Two MCA aneurysms were treated with single coiling, and the supraclinoid ICA fenestration aneurysm was coiled under stent assistance. The postoperative recovery was uneventful. At this time, a literature review was performed on the role of EVT in supraclinoid ICA fenestration aneurysms. A total of 13 supraclinoid ICA fenestration aneurysms treated by EVT in 11 cases, including our case, were obtained. After EVT, good outcomes were obtained in all cases. To our knowledge, this is the first study to review the role of EVT for supraclinoid ICA fenestration aneurysms. Our case report and literature review indicated that EVT for such aneurysms may be feasible and act as a therapeutic alternative.

Endovascular treatment of an aneurysm associated with fenestration of the supraclinoid internal carotid artery: Case report and review of the literature

Background

Fenestrations or divisions of the vascular lumen into separate channels appear to be common anatomical variations in patients with intracranial aneurysms. The most frequent sites of occurrence are the anterior communicating artery (ACom), followed by vertebrobasilar and middle cerebral artery (MCA) locations.

Case presentation

A 61-year-old female was brought to the emergency department after experiencing severe headache with abrupt onset, nausea, and vomiting. Clinical examination on arrival showed a drowsy patient (GCS 14), with neck stiffness, but no cranial nerve palsies or other neurological deficits (Hunt-Hess 2). Non-contrast head CT and CT angiography revealed subarachnoid and intraventricular hemorrhage (modified Fisher 4) and two saccular aneurysms, one located on the right supraclinoid ICA with peripheral calcifications, measuring 20 × 12 mm, the second on the left MCA bifurcation, 6 × 4 mm. 3D rotational angiography revealed a right ICA fenestration located between the ophthalmic (OA) and posterior communicating artery (PCom). The proximal part of the fenestration harbored a large saccular aneurysm projecting superiorly with the neck engulfing the origin of the fenestration; due to the favorable neck and geometry of the aneurysm, endovascular coil occlusion was chosen as a treatment option without balloon or stent assistance. The decision was taken to clip the MCA aneurysm.

Conclusion

Supraclinoid ICA fenestrations are rare anatomical variations. Endovascular treatment of supraclinoid ICA fenestration-related aneurysms is feasible and safe, with the notable concern of perforators originating from the limbs.

Association of cerebral infarction with vertebral arterial fenestration using non-Newtonian hemodynamic evaluation

PURPOSE

Cerebral artery fenestration is a rare vascular anomaly, but its existence has been increasingly documented. The association of cerebral infarction and fenestration is of great clinical interest, and the exact underlying mechanism remains unclear. This study aims to identify risk factors contributing to cerebral infarction by computational hemodynamics analysis.

METHODS

Eight patients with image findings of fenestration structure were recruited in this research, in which four suffered fenestration-related cerebral infarction (A series) while the other four (B series) were set as control matched by the fenestration size. Three-dimensional models were reconstructed from the MRA images and computational simulations with non-Newtonian flow model were performed to get interested hemodynamic characteristics.

RESULTS

The blood flow pattern was relatively separated along two channels of fenestration in series A compared with series B cases in Group 1-2, however, no significant difference was shown in Group 3-4. Quantitatively, planes were cut in the middle of fenestrations and the ratio of mass flow rate and area was calculated at systolic peak. Results showed that the side of the dominant blood supply was opposite between A and B series, and the dominant side was also opposite between small and large fenestrations. In infarction cases, the basilar top was distributed with larger areas of detrimental hemodynamic indicators and a larger concentrated high viscosity region.

CONCLUSION

The flow division condition throughout the fenestration structure has a key impact on further flow redistribution and flow pattern. The blood viscosity has the potential to be a useful tool in identifying the risk factors for cerebral infarction and more emphasis should be placed on the hemodynamic environment at superior cerebellar arteries.

Endovascular Treatment of Fenestration-related Aneurysms : Morphological Features, Operative Techniques and Therapeutic Outcomes

PURPOSE

Endovascular treatment of fenestration-related aneurysms (FAs) is prone to technical challenges, given the inherent complexities. Herein, we have analyzed FAs in terms of angioarchitectural characteristics and outcomes achieved through endovascular intervention.

METHODS

Data accrued prospectively between January 2002 and July 2020 were productive of 105 FAs in 103 patients, each classifiable by the nature of incorporated vasculature as proximal portion, fenestrated limb, or distal end. Our investigation focused on clinical and morphological outcomes, with emphasis on technical aspects of treatment.

RESULTS

The FAs selected for study originated primarily in anterior communicating artery (AcomA: 88/105, 83.8%), followed by basilar (7/105, 6.7%), anterior cerebral (4/105, 3.8%), and internal carotid (3/105, 2.8%) arteries. In nearly all locations, proximally situated aneurysms (43/105, 41%) were more frequent than aneurysms arising at distal ends (3/105, 2.8%), but the majority of AcomA lesions involved fenestrated segments (58/88, 65.9%); and most fenestrated channels (90/105, 85.7%) were asymmetric in size. Orifices of smaller fenestrated limbs were intentionally compromised during coil embolization in 23 aneurysms (21.9%), achieving complete (n = 19) or incomplete (n = 4) compromise, without resultant symptomatic ischemia. Saccular occlusion proved satisfactory in 77 lesions (73.3%). In follow-up monitoring of 100 patients for a mean period of 35.3 ± 26.5 months, 17 instances of recanalization (17.0%) occurred (minor, 9; major, 8). There was no recanalization of aneurysms with compromised limbs.

CONCLUSION

Coil embolization of FAs is safe and effective, enabling tailored procedures that accommodate aberrant angioanatomic configurations. Compromise of a single limb during coiling also appears safe, conferring long-term protection from recanalization.

Supraclinoid Internal Carotid Artery Fenestration with Associated Aneurysm: Case Report and Literature Review

Fenestration of the supraclinoid internal carotid artery (ICA) is extremely rare and may occasionally be associated with saccular aneurysms; nevertheless, the natural history remains unclear. The authors reviewed the cases of fenestration of the supraclinoid ICA and evaluated the clinical characteristics and angioarchitecture with particular focus on the incidence for aneurysm development and rupture. Previously reported 24 cases and 1 new case from our institute were examined for the presence of aneurysms (including size and presence of bleb) leading to subsequent subarachnoid hemorrhage (SAH). Furthermore, 16 cases with sufficient information were classified into one of the three types according to the developmental condition of fenestration and fusion site: Type A (developed fenestration in which the ICA appears to duplicate [two cases]); Type B (hypoplastic fenestration fused to the ICA at the origin of the posterior communicating artery [Pcom] [six cases]); and Type C (hypoplastic fenestration fused to the Pcom itself or appeared to be a duplicated Pcom [eight cases]). In type A, the two cases had an aneurysm (100%), one of which caused SAH (50%). In type B, all six cases had an aneurysm (100%), and one of five led to SAH (20%) (one case lacked information regarding SAH). In type C, five of the eight cases had an aneurysm (62.5%), with no SAH (0%). The result suggested that the extent of development of fenestration and the location of fusion are related to the incidence of aneurysms and risk for rupture.

An interdisciplinary approach to the treatment of a complex infraclinoidal internal carotid artery aneurysm

We present the case of a 49-year-old woman with sudden onset of severe headaches and a ruptured aneurysm located inside the fenestration of the infraclinoid part of the internal carotid artery in the segments C4 and C5 distal to the origin of the ophthalmic artery. An interdisciplinary approach enabled the successful treatment of the aneurysm by wrapping and stent-assisted coiling. We discuss this rare congenital anomaly of a fenestrated internal carotid artery together with the 12 other cases published worldwide.

Fenestration of the supraclinoid segment of the ICA and associated aneurysms: a case report with literature review

The supraclinoid ICA fenestration (SIF) is considered an extremely rare congenital anomaly. However, most of the reported cases of SIF are associated with intracranial aneurysms either ruptured or unruptured. We report the case of a 55-year-old patient with a right SIF and an unruptured, large, wide-necked aneurysm located on the larger limb of the fenestration and a second small aneurysm distal to the SIF. The aneurysms were treated with a Pipeline flow-diverter stent, achieving the complete reconstruction of the anatomy of the carotid siphon. The literature concerning these peculiar anatomic conditions has been reviewed, allowing discussion about treatment of such associated lesions.

Basilar artery fenestration: an unusual possible cause of ischaemic stroke?

Basilar artery fenestration is an uncommon congenital dysplasia and may be associated with ischaemic stroke. We present a case of a previously healthy 36-year-old man who presented with vertigo and vomiting. MRI showed posterior circulation territory infarction. High-resolution magnetic resonance angiography revealed a slit-like fenestration in the basilar artery. This patient had no traditional vascular risk factors or aetiology of cryptogenic stroke. The patient recovered from his neurological deficit after antiplatelet therapy and was given prophylactic aspirin therapy. There was no recurrence of symptoms after 12 months of follow-up.

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.

Supraclinoid internal carotid artery fenestration harboring an unruptured aneurysm and another remote ruptured aneurysm: case report and review of the literature

A fenestration of the supraclinoid internal carotid artery (ICA) is a rare congenital condition. We report an aneurysm arising from the proximal end of an ICA fenestration that was treated by endovascular coiling. Three-dimensional rotational angiography of preoperative cerebral angiography provided an understanding of the complex anatomy of the aneurysms associated with the fenestration and may facilitate the clinical decision regarding the treatment option. Endovascular coiling appears to be safe and effective for treating an aneurysm originating from a fenestration on the supraclinoid ICA, which is a difficult lesion to treat using a conventional surgical approach.

Fenestration of supraclinoid internal carotid artery and associated aneurysm: embryogenesis, recognition, and management

OBJECTIVE

Fenestration of internal carotid artery (ICA) is extremely rare and may be associated with aneurysms arising from the fenestrated segment. Here we report two cases with successful surgical clipping of associated saccular aneurysms, and we systematically review the 12 previously reported cases.

METHODS

In one case of 39-year-old female patient, the aneurysm and fenestration were found incidentally in the course of a workup for headaches and a thyroid nodule. In the second case, a 32-year-old female patient, the aneurysm was associated with subarachnoid hemorrhage in the setting of suspected postpartum eclampsia. In both instances the fenestration involved the supraclinoid ICA, and the aneurysm arose from the duplicated segment proximal to the origin of the posterior communicating artery. The aneurysms were more proximal than typical posterior communicating artery aneurysms, and fenestration was suspected by rotational three-dimensional angiography, and confirmed at surgery.

RESULTS

In both instances the aneurysm was approached via an extended pterional craniotomy. In one case, partial anterior clinoidectomy was necessary, along with decompression of the optic nerve canal for optimal exposure of the aneurysm neck. Clip reconstruction was successful, obliterating the aneurysm and preserving ICA patency.

CONCLUSIONS

ICA fenestration should be considered when one analyzes ventral supraclinoid ICA aneurysms. In these and other reported cases, aneurysm is generally amenable to surgical clipping despite broad neck incorporating the fenestrated arterial segment.

A rare case of supraclinoid internal carotid artery (ICA) fenestration in combination with duplication of the middle cerebral artery (MCA) originating from the ICA fenestration and an associated aneurysm

Fenestrations and duplications of the cervical and intracranial arteries are rare anatomic variants, reported to be associated with aneurysms or other vascular anomalies. We here present a patient with a supraclinoid ICA fenestration in combination with a duplication of the MCA originating from the ICA fenestration and an associated aneurysm.

Fenestration of a supraclinoid internal carotid artery associated with dual aneurysms: case report

BACKGROUND AND IMPORTANCE

We present a rare case of fenestration of the left supraclinoid intracranial internal carotid artery with 2 associated aneurysms arising proximally and distally from the fenestration that were successfully treated with endovascular coil embolization. This is the first report of these types of aneurysms treated with coiling alone.

CLINICAL PRESENTATION

A 47-year-old woman underwent a diagnostic workup; magnetic resonance angiography incidentally revealed 2 tandem aneurysms at the supraclinoid and paraclinoid portion of the left internal carotid artery. Angiography revealed fenestration of the left supraclinoid internal carotid artery with 2 aneurysms both proximal and distal to the fenestration. The patient underwent endovascular coil embolization of the aneurysms simultaneously. The smaller trunk was intentionally occluded to achieve complete packing of the proximal aneurysm. Both aneurysms were totally occluded, and no neurological deficits developed in the patient.

CONCLUSION

Based on previous reports, fenestration has the potential to form an aneurysm, and there seemed to be a relatively high incidence of rupture if accompanied by aneurysm. Coiling is one good option to treat aneurysms and should be considered when multiple aneurysms exist because all aneurysms can be treated simultaneously. Proximal occlusion of the smaller trunk is acceptable because of a retrograde flow from the distal end, even if one exists.

Congenital external carotid-internal carotid artery anastomosis diagnosed by MR angiography

We present what we believe is the first report of external carotid-internal carotid artery anastomosis, which forms a large arterial ring at the proximal cervical internal carotid artery (ICA). If the small channel of the proximal cervical ICA is occluded, the remaining large channel of the external carotid artery may be diagnosed as a nonbifurcating cervical carotid artery.