Agenesis Of Internal Carotid Artery Research Articles

Combined lie's type D and type A agenesis of the left internal carotid artery diagnosed by magnetic resonance angiography.

To report an unusual case of combined Lie's types A and D of internal carotid artery (ICA) agenesis, diagnosed by magnetic resonance angiography (MRA). A 60-year-old woman with dizziness underwent cranial magnetic resonance imaging (MRI) and MRA of the intracranial region for the evaluation of brain and vascular lesions. The magnetic resonance machine was a 3.0-T scanner. MRI showed no abnormalities, except for multiple small white matter lesions. MRA showed that the left ICA was absent, except for the supraclinoid segment, and an anastomotic vessel was present between the paraclinoid segments of the bilateral ICAs, indicating Lie's type D ICA agenesis. The left posterior communicating artery (PCoA) was also present. Thus, there were also features of type A ICA agenesis. The anastomotic vessels between the bilateral ICAs and ipsilateral PCoA were relatively small in caliber. Lie's type D ICA agenesis usually does not communicate with the anterior and posterior circulations. We encountered a case of combined type D and type A ICA agenesis. To our knowledge, no similar case has been reported in the English literature. This is the second case of type D ICA agenesis with patent ipsilateral PCoA. We speculate that in case of type A ICA agenesis, when the development of the PCoA is insufficient to support collateral blood flow, an anastomotic vessel between bilateral ICAs may develop.

Congenital Left Internal Carotid Artery Agenesis with Intercavernous Anastomosis

Congenital Left Internal Carotid Artery Agenesis with Intercavernous Anastomosis

Right-sided aortic arch with isolation of the left innominate artery and hypoplasia of the left internal carotid artery.

Here, we report a case of the right-sided aortic arch with isolation of the left innominate artery and hypoplasia of the left internal carotid artery. A 42-year-old male patient underwent a whole-body computed tomography angiography (CTA) examination upon the clinical suspicion of vasculitis. CTA revealed a right-sided aortic arch with the isolation of the left innominate artery and hypoplasia of the left internal carotid artery. The right-sided aortic arch, with the isolation of the left innominate artery, is a scarce vascular variation that may occur with other cardiovascular anomalies such as ventricular septal defect. It can be asymptomatic or can present with symptoms of subclavian steal syndrome. Although its association with the agenesis of the left internal carotid artery has been reported, its association with the hypoplasia of the left internal carotid artery has not been reported previously to the best of our knowledge.

Unilateral Agenesis of the Internal Carotid Artery: A Report of Two Rare Cases

Background: Internal carotid artery (ICA) agenesis occurs when one or both of the blood vessels that supply blood to the brain do not develop. Congenital agenesis of the ICA rarely occurs. It is usually asymptomatic but may sometimes associate with neurological symptoms such as migraine and pulsatile tinnitus. Moreover, differentiating it from occlusion of ICA is important in patients with stroke. Case Report: We report two cases (63-years-old man and 69-year-old woman) of asymptomatic unilateral ICA agenesis who were referred to our cardiovascular hospital for coronary artery bypass graft. Due to a suspicious history of transient ischemic attack, the patients underwent carotid ultrasonography. With findings suggestive of unilateral ICA agenesis at color Doppler, patients underwent computed tomography angiography that confirmed the diagnosis. Conclusion: Suspecting ICA agenesis at color Doppler imaging of the neck and differentiating it from occluded ICA at CT angiography is important for correct diagnosis and management of the patients.

Unilateral rete mirabile in multiple intracranial arteries with ipsilateral agenesis of the internal carotid artery: a case report

BackgroundRete mirabile of the cerebral artery is a rare anomaly, with most previous cases occurring in the middle cerebral artery or internal carotid artery. Here, we present the first report of unilateral rete mirabile in multiple intracranial arteries with ipsilateral internal carotid artery agenesis.Case presentationA 64-year-old Japanese woman was brought to the emergency department of our hospital in a deep coma. Computed tomography of the head showed severe intraventricular hemorrhage with subarachnoid hemorrhage. Computed tomography angiography showed not only congenital left internal carotid artery agenesis, but also rete mirabile of the left posterior communicating artery, the left posterior cerebral artery, and the left anterior cerebral artery. This unilateral vessel anomaly complex may have contributed to the formation of a peripheral aneurysm arising from a perforating branch of the pericallosal artery, which ruptured. The patient underwent urgent bilateral external ventricular drainage, but deteriorated and was declared brain dead.ConclusionsWe report the first case of unilateral rete mirabile in multiple intracranial arteries. Because the cerebral arteries in patients with rete mirabile may be vulnerable, close attention should be paid to the development of cerebral aneurysms.

Internal Carotid Artery Agenesis: A Rare Incidental Finding

Internal carotid artery agenesis is a very rare anomaly, occurring during the early stages of embryonic development. We report the clinical presentation and imaging findings both on CT and MRI of the incidental finding of a left internal carotid agenesis in a 40 year old female. Magnetic resonance angiography was the most valuable diagnostic tool for the positive diagnosis, showing the absence of the left internal carotid artery, with left circulation arising from the right anterior cerebral artery and left posterior cerebral artery. Unenhanced computed tomography was used to differentiate between internal carotid agenesis and hypoplasia. Imaging should also look for associated malformations such as aneurysms as well as ischemic and hemorrhagic complications.

Bilateral Internal Carotid Artery Agenesis : Very Rare Cause of Bilateral Pulsatile Tinnitus

Bilateral internal carotid artery agenesis is a very rare congenital anomaly. Intracranial blood circulation in the affected internal carotid artery side is provided by collateral vasculature, contralateral internal carotid artery through the anterior communicating artery, and from the vertebrobasilar system through the posterior communicating artery. People with this abnormality may be asymptomatic for many years. However, patients may also be present with ischemic stroke orsubarachnoid hemorrhage, headache, and blurred vision. Diagnosis is usually incidental by the performance of carotid artery doppler ultrasonography or cervical/cranial magnetic resonance imaging owing to other symptoms. We report a case of bilateral internal carotid artery agenesis with pulsatile tinnitus lasting five years in the light of clinical presentation and imaging findings.

ICA agenesis with transcavernous anastomosis: a systematic review.

To present two cases of Internal Carotid Artery (ICA) agenesis and conduct a systematic review to assess for associations with other anomalies and intracranial aneurysms. We performed a retrospective review of published cases of patients with ICA agenesis with intercavernous anastomosis in MEDLINE database on August 2022 using search terms "internal carotid artery", "agenesis" and "transcavernous anastomosis". We also included two cases of ICA agenesis with type D collateral that we encountered. Total of 46 studies that included 48 patients and two of our cases resulted in 50 patients. Only 70% of studies reported the location of a collateral vessel of which more than two-thirds were on the floor of sella. More than half of the vessels connected cavernous segments of ICA. A1 segment ipsilateral to the side of ICA agenesis was absent in most of the cases but was not true for all cases. Aneurysm was seen in more than one-quarter of the patients. It can also mimic microadenoma as in prior reported cases as well as in one of our cases. ICA agenesis with type D collateral is a rare anomaly but clinically relevant due to the increased risk of an aneurysm or mimic microadenoma or false alarm for occlusion of ICA but knowledge of this rare variant can help in better management of these patients.

Proposed new classification for internal carotid artery segmental agenesis based on embryologic and angiographic correlation.

Internal carotid artery (ICA) agenesis is a rare anatomical variant that can involve different segments of the ICA. Although many authors proposed their own classifications of this variant basing on different criteria, none of these allows to include all the cases described in the literature. The aim of the authors is to propose a new classification that allows to include all cases of ICA agenesis described until now. The study is based on the review of all the cases of ICA agenesis described in the literature and of the classifications already proposed. After the analysis of these cases, we looked for the limits of each classification to elaborate a new more complete one. We found 228 cases of ICA agenesis. Among them 40 were not includible in the existing classifications. For this reason, we proposed a new classification based on the type of flow compensation and on the embryological events that determine the different variants. The flow is compensated in Type I by the Circle of Willis; in Type II by the non-regression of an embryonic artery; in Type III by the presence of an arterio-arterial anastomosis and in Type IV by external-internal carotid arteries anastomoses. After the literature review, we proposed a new comprehensive classification based on the detailed analysis of arterial embryology. Even if all the embryological details that determine this complex variant are not completely understood yet, this classification allows to include all the cases described in literature.

Agenesis of the Left Internal Carotid Artery and Congenital Pituitary Aplasia

Agenesis of the Left Internal Carotid Artery and Congenital Pituitary Aplasia

Dolichoectasia of the left internal carotid artery with unilateral agenesis of the right internal carotid artery

Dolichoectasia of the left internal carotid artery with unilateral agenesis of the right internal carotid artery

Cerebrovascular disorders associated with agenesis of the internal carotid artery: Findings on digital subtraction angiography.

Agenesis of the internal carotid artery (ICA) is a rare vascular condition that is complicated by intracranial aneurysms and rete mirabile. The altered hemodynamics caused by this distinctive cerebrovascular angioarchitecture can cause ischemic or hemorrhagic accidents. Data on clinical and radiographic features have been limited to describing this vascular pattern. We present five cases of agenesis of the internal carotid artery confirmed by digital subtraction angiography (DSA) and further investigate the influence of altered angioarchitecture on the integrity of intracranial morphology. Cases of ICA anomalies were screened from the patients who underwent DSA in two hospitals. Clinical manifestation, radiographic features, management, and outcomes were retrospectively reviewed. Five patients [mean age 44 years (range, 30-65 years)] were included. Two patients presented with subarachnoid hemorrhage, one with cognitive impairment, one with dizziness, and one with intermittent headache. DSA demonstrated that three cases were complicated by intracranial aneurysms, one by dural arteriovenous fistula, and one by rete aneurysm. Three patients underwent endovascular treatment and one underwent bypass surgery. No patient died or experienced cerebrovascular accident during short-term follow-up. ICA agenesis can be complicated by disorders such as intracranial aneurysm, rete aneurysm, and dural arteriovenous fistula. This suggests that ICA agenesis is associated with a tendency towards disrupted cerebrovascular homeostasis resulting from altered hemodynamics.

Developed Circuminfundibular Anastomosis Associated with Vascular Abnormalities

We report a 74-year-old male patient who presented with left hemiplegia and disturbance of consciousness. Computed tomography revealed diffuse subarachnoid hemorrhage, which was prominent in the right Sylvian and basal cisterns. Digital subtraction angiography revealed absence of the C2 segment of the right internal carotid artery (ICA) and a significantly developed circuminfundibular anastomosis. Occlusion of the bilateral vertebral arteries (VAs) was also seen. The upper basilar artery was supplied by the circuminfundibular anastomosis and collaterals from the VAs. Since the source of bleeding was unclear, the patient was treated conservatively. Circuminfundibular anastomosis is a potential anastomosis around the pituitary stalk. It is formed by the superior hypophyseal arteries, prechiasmal arteries, and infundibular arteries bilaterally. Agenesis of the contralateral ICA often leads to development of ICA-ICA anastomoses. In this case, the anastomosis developed due to agenesis of the C2 segment of the right ICA and occlusion of the bilateral VAs.

Stroke in sickle cell disease in association with bilateral absence of the internal carotid arteries. Case report

BackgroundCongenital absence of the internal carotid artery (ICA) is a highly infrequent congenital incidence and occurs in less than 0.01% of the population; bilateral absence is exceedingly rare, diagnosed below 10% of the unilateral absence of the ICA. Sickle cell disease (SCD) is a serious disorder and carries a high risk of stroke.Case presentationWe present a five-year-old child with SCD who experienced an ischemic stroke episode with epileptic seizures. Neuroimaging revealed the agenesis of both ICAs. The frequency, embryology, and collateral pathway of the vascular anomaly as the clinical presentation, of this rare hematologic disease, are discussed.ConclusionsSickle cell disease (SCD) carries a high risk of stroke. Congenital absence of ICA occurs in less than 0.01% of the population; bilateral absence is diagnosed below 10% of the unilateral absence of the ICA.

Pediatric moyamoya disease associated with ipsilateral internal carotid artery agenesis: illustrative case

BACKGROUNDAlthough most cases of internal carotid artery (ICA) agenesis are clinically silent due to a well-developed collateral pathway, some cases may develop ischemic symptoms when they are associated with other occlusive cerebrovascular disorders. The authors describe herein the first case with ICA agenesis that developed ischemic attack because of coincidence with moyamoya disease.OBSERVATIONSA 3-year-old girl was admitted to the authors’ hospital due to sudden onset of right arm weakness followed by clonic convulsion. Skull computed tomography could not identify the carotid canal on the left side. Simultaneously, magnetic resonance (MR) imaging and MR angiography demonstrated the luminal stenosis and outer diameter reduction of the carotid fork and posterior cerebral artery on the left side. She was diagnosed with unilateral moyamoya disease associated with ipsilateral ICA agenesis. She successfully underwent combined bypass surgery on the left side and has been free from any cerebrovascular events during a follow-up period of 6 months.LESSONSWhen patients with ICA agenesis develop ischemic symptoms, careful investigation of the cause and appropriate care, including surgical treatment, are required.

Agenesis of the internal carotid artery associated with intracranial aneurysms: Endovascular treatment and intraoperative complications management.

Agenesis of the internal carotid artery (ICA) is a rare condition, whereas the association of this condition and the presence of intracranial aneurysms is higher in comparison to patients with normal vasculature. Endovascular treatment of this particular subgroup of patients has been described, but complications associated during treatment have not. Herein, we describe the endovascular treatment of intracranial aneurysms in two cases complicated with coil protrusion and in-stent thrombosis in the setting of agenesis of the ICA which were treated successfully without clinical compromise. One-year follow-up digital subtraction angiography demonstrated the complete obliteration of both aneurysms. In most of the cases, coil protrusion does not require further intervention; nevertheless, in the setting of ICA agenesis, stent placement is a potential alternative. In-stent thrombosis should be treated promptly with the available tools, in our case intra-arterial Alteplase reperfused the parent vessel.

Previously unreported variant collateral supply in an acute stroke patient with anomalous common and internal carotid artery anatomy undergoing mechanical thrombectomy.

Agenesis of the common carotid and internal carotid arteries are rare entities. Approximately 100 cases of internal carotid artery (ICA) agenesis are reported in the literature, and even fewer cases of common carotid agenesis. The collateral supply in such cases is well described and typically follows one of only a small number of variations. Lie classically described six major pathways of collateral supply in ICA agenesis (Congenital Anomalies of the Carotid Arteries. Excerpta Medica, Amsterdam, 1968; 35). Vasovic etal. in a comprehensive review of all published cases of common carotid agenesis have similarly described the typical variations in collateral supply seen in this setting. Neither described the anatomy presented here.

Unilateral absence of internal carotid artery: A rare case report

Unilateral absence of internal carotid artery (ICA) is a rare congenital anomaly. We present the case of a 35-year-old man with episodes of recurrent strokes in the past and now presenting with right-sided upper limb weakness. Radiological diagnostic workup revealed a thin left ICA in the neck with non-visualization beyond petrous bone in the intracranial course. The ipsilateral brain parenchyma is supplied by vessels from the contralateral side of the Circle of Willis. As the patient had no evidence of a cerebrovascular accident on radiological evaluation and no neurological signs and symptoms, he was discharged with anticoagulant medications with the advice of follow-up. This is the first report to describe a case of ICA agenesis with a pattern of collateral circulation that doesn’t fit any of the six types described by Lie.

Management of symptomatic posterior circulation flow aneurysms associated with agenesis of the internal carotid artery

Internal carotid artery agenesis, unilateral or bilateral is a rare congenital anomaly. Cerebral circulation challenged by this lack of anterior supply is compensated by increased flow through the posterior circulation and circle of Willis. This hyperdynamic circulation results in flow-related aneurysms, especially along the branching segments. We present the clinical, imaging and endovascular management of three symptomatic patients with discussion of relevant literature.

Internal Carotid Artery Agenesis Associated with Contralateral Posterior Communicating Artery and Basilar Tip Aneurysms: A Case Report

Background: The absence of the internal carotid artery is an extremely rare congenital anomaly with a reported incidence of 0.01%. As with other anatomical vascular variants, they usually follow a silent course and are typically discovered incidentally. Case Presentation: We report an unusual case of a 30-year-old male medically free who presented to the emergency department with sided numbness involving both upper and lower limbs while he was swimming. Brain imaging revealed a congenital absence of the right internal carotid artery in association with basilar tip saccular aneurysm and right posterior communicating artery aneurysm. The patient was treated successfully with endovascular stent-assisted coiling of the basilar artery and stenting of the right posterior communicating artery. Conclusion: The main significant impact that this condition harbors is the high association with intracranial aneurysms secondary to hemodynamic stress on other intracranial arteries with compensatory increased flow. This case report supports this hypothesis and shows complex endovascular management.