Fusiform aneurysm associated with fenestration of the posterior communicating artery

Treatment of an intracranial aneurysm in the setting of fenestration of cranial division of the internal carotid artery: Technical considerations and a literature review

Although rare, cerebral arterial fenestration may present challenges in diagnosis and treatment. Here we present a case of a supraclinoid internal carotid artery (ICA) fenestration adjacent to an ICA aneurysm, successfully treated with balloon-assisted coil embolization. A female in her 50's presented with an acute subarachnoid hemorrhage from a ruptured left ICA-ophthalmic artery (OA) aneurysm. Digital subtraction angiography revealed a focal ICA fenestration distal to the posterior communicating artery (Pcom). The patient underwent successful coil embolization of the aneurysm using the balloon-assisted technique. No immediate hemorrhagic, thromboembolic, or neurological complications were observed. The patient was discharged in good condition after 2 weeks of hospitalization. A comprehensive literature review of 33 cases was subsequently performed to understand the characteristics of this condition. Cases involving the cranial division of the ICA forming the fenestration exhibited caliber differences significantly more frequently (p = 0.02). Embryological insights revealed distinctions between the cranial divisions of the ICA, influencing fenestration morphology and associated aneurysm formation. Endovascular treatment poses the risk of vascular injury, necessitating the identification of this variation and procedural planning.

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.

Fenestrations and Various Duplications of the Posterior Communicating Artery in the Prenatal and Postnatal Periods

BACKGROUND

The 2 paired arteries-the posterior communicating arteries (PCoAs) and the precommunicating parts of the posterior cerebral arteries-form the so-called posterior segment of the cerebral arterial circle on the base of the brain. A number of (ab)normal morphologic features were described in the literature (e.g., unusual kinking, or extreme elongations, hypoplasia, duplications, fenestrations, the infundibular widening, or aplasia of the PCoA in the prenatal and/or postnatal periods). The aim of this study was to analyze an incidence of various fenestrations and duplications of the PCoA, and describe their general features and their association with other vascular abnormalities.

METHODS

The research was performed on the brains of 200 human fetuses and 377 adult cadavers of both genders and different ages using microdissection and macrodissection methods.

RESULTS

There were 0.34% cases with PCoA fenestrations and 3.12% cases with various PCoA duplications. Their morphologic features were described and compared with the similar PCoA abnormalities recorded in the scientific literature. There was no association between the PCoA and either duplication or aneurysm in adult cases.

CONCLUSIONS

After thorough examination, the fenestrations and duplications of the PCoA are distinguished as 2 special forms of vascular abnormalities, and the PCoA duplications are characterized as partial and total. Furthermore, whereas the low incidence of a fenestration of the PCoA suggests it to be a sufficiently rare phenomenon, the duplications of the PCoA trunk are fairly frequent, especially concerning its terminal segment.

Extremely long posterior communicating artery diagnosed by MR angiography: report of two cases

We report two cases of an extremely long left posterior communicating artery (PCoA) diagnosed by magnetic resonance (MR) angiography. The PCoA arose from the normal point of the supraclinoid internal carotid artery and fused with the posterior cerebral artery (PCA) at its posterior ambient segment, forming an extremely long PCoA and extremely long precommunicating segment of the PCA. To our knowledge, this is the first report of such variation. Careful observation of MR angiographic images is important for detecting rare arterial variations. To identify these anomalous arteries on MR angiography, partial maximum-intensity-projection images are useful.

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.

Aneurysmal subarachnoid hemorrhage with concomitant posterior communicating artery fenestration

Fenestrations of the posterior communicating artery (PCoA) are extremely rare. Associated aneurysms have only been documented three times in the literature, and none associated with a subarachnoid hemorrhage. We describe a 52-year-old female who presented with a subarachnoid hemorrhage secondary to a ruptured saccular aneurysm at the proximal limb of a fenestrated right PCoA. The patient was also found to have bilateral middle cerebral artery (MCA) aneurysms. Surgical management included surmising the etiology of the subarachnoid hemorrhage with subsequent clipping of both the right PCoA and MCA aneurysm. The potential embryological mechanisms leading to a PCoA fenestration are discussed.

Duplicate origin of the posterior communicating artery diagnosed by magnetic resonance angiography

Extremely rarely, a posterior communicating artery (PCoA) of "duplicate origin" occurs when two branches of the PCoA arise separately from the supraclinoid segment of the internal carotid artery (ICA) and quickly fuse to form an arterial ring. Three such cases previously reported were described as "fenestration." We report the case of this rare variation diagnosed by magnetic resonance angiography and discuss the differentiation of PCoA of duplicate origin from PCoA fenestration, supraclinoid ICA fenestration, and hyperplastic anterior choroidal artery.