Bilateral agenesis of the internal carotid artery associated with basilar artery aneurysm treated via the endovascular route. A case report

Bilateral internal carotid artery agenesis coexisting with bovine aortic arch: case report and literature review

This case study aims to elucidate the rare occurrence of bilateral internal carotid artery agenesis combined with a bovine aortic arch. The main objectives are to explore the incidence, embryological origins, clinical manifestations, and associated anomalies of this unique vascular condition. The study involves a detailed investigation of a 55-year-old male with a history of recurrent transient ischemic attacks (TIAs) using MRI and CT scan. The patient's medical history, clinical examination, and imaging results were systematically analyzed to provide a thorough understanding of the anatomical variations. The main findings include the rare coexistence of bilateral ICA agenesis and a bovine aortic arch, making this the 39th documented occurrence of bilateral ICA agenesis and the first recorded instance of its association with a bovine aortic arch. Also, the study highlighted the demographic characteristics, clinical presentations, and associated anomalies observed in the 38 documented cases of bilateral internal carotid artery agenesis. This case report contributes valuable insights into the rarity of bilateral internal carotid artery agenesis and its unprecedented association with a bovine aortic arch. The findings emphasize the importance of heightened anatomical awareness in clinical practice, particularly. Recognizing and understanding such variations is crucial for accurate diagnosis, appropriate management, and improved patient outcomes. Further research in this area is warranted to deepen our understanding of these complex vascular anomalies.

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

BACKGROUND AND PURPOSE

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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 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.

A Rare Case of Congenital Internal Carotid Artery Agenesis and Contralateral Internal Carotid Artery Aneurysm

Agenesis of the internal carotid artery (ICA) is a rare congenital entity. This anomaly is typically occult in nature. However, the effects of an incidental discovery secondary to a contralateral ICA aneurysmal rupture can be devastating. The association between agenesis of the ICA and contralateral intracranial aneurysm formation is significantly higher than de novo incidental intracranial aneurysms in the general population. It is important to evaluate the presence of a contralateral intracranial aneurysm in the setting of known agenesis of the ICA. This allows for the performance of prophylactic embolization and characterizes collateral cerebral circulation.

Cerebral Aneurysms with Internal Carotid Artery Agenesis: A Unique Case Similar to Moyamoya Disease and Literature Review

Internal carotid artery (ICA) agenesis/aplasia is occasionally accompanied with cerebral aneurysms caused by hemodynamic stress. If the aneurysms are located around the circle of Willis, they are managed with clipping or coil embolization. Herein, we report a case of ICA agenesis with perforating artery aneurysms treated successfully with revascularization. Moreover, a literature review of ICA agenesis with cerebral aneurysms was performed to compare with the current case. We conducted a literature review using data from PubMed. A secondary search was also performed by reviewing the references of each article previously searched. In our case, the aneurysms shrank and disappeared after direct and indirect bypass surgeries, and indirect bypass developed as in moyamoya disease (MMD). The epidemiological and clinical features of aneurysms accompanied with ICA agenesis were identified via a literature review. Aneurysms with ICA agenesis categorized as type F based on the Lie classification system, or referred to as rete mirabile, are occasionally located in an untreatable site; hence, they cannot be treated with clipping or coil embolization. Moreover, results showed that previous studies did not use revascularization for the treatment of aneurysm. In conclusion, if an aneurysm with ICA agenesis is difficult to approach directly or via an endovascular procedure, revascularization can be a treatment option.

Unilateral agenesis of internal carotid artery associated with superior cerebellar artery aneurysm and anomalous origin of ophthalmic artery arising from the ipsilateral posterior communicating artery

Congenital agenesis of the unilateral internal carotid artery is a rare anomaly. The agenesis of the internal carotid artery is associated with a higher incidence of intracranial aneurysms. This report describes a rare case of internal carotid artery agenesis associated with an aneurysm of the left superior cerebellar artery in a 52-year-old woman. The left middle cerebral artery was supplied from the vertebrobasilar system through the dilated left posterior communicating artery associated with anomalous origin of the left ophthalmic artery from the left posterior communicating artery. This report demonstrates a rare combination of left internal carotid artery agenesis with associated intracranial aneurysm and anomalous origin of the ophthalmic artery, discussion of embryogenesis, clinical significance, and imaging findings.

Congenital absence of the bilateral internal carotid artery: a review of the associated (ab)normalities from a newborn status to the eighth decade of life

PURPOSE

Due to the fact that the internal carotid artery (ICA) is responsible for nourishing two thirds of the brain volume, our aim was to inspect the morphofunctional consequences of the bilateral lack of this artery.

METHODS

In order to examine this condition, we referred to both the library archive of our Faculty of Medicine and electronic databases of anatomical and clinical reports that included the following keywords: "absence," "aplasia," or "agenesis" in combination with "internal carotid artery," "common carotid artery," or only "carotid artery."

RESULT

We found 60 recorded cases of the bilateral ICA absence in the subjects of newborn status to the eighth decade of life, which had been discovered in 20 countries. The following ten parameters were described: the embryological base, terminology, history, incidence, general data, differential diagnosis, collateral circulation, the associated vascular aplasia and/or other variants, pathophysiology, and the importance in praxis.

CONCLUSION

This review noted all the cases of the bilateral ICA aplasia published for the past 104 years. Although there were 11.6% of cases of the associated cerebral aneurysms and 1-4 cases of 16 other diseases, approximately one quarter of the cases was without any pathology.

Segmental Aplasia of Bilateral Internal Carotid Arteries Accompanied by Intracranial Aneurysms: A Case Report

A 68-year-old woman presented with segmental aplasia of bilateral internal carotid arteries accompanied by unruptured intracranial aneurysms. The abnormality was discovered incidentally at the age of 44 years. Cerebral angiography showed occlusion of bilateral internal carotid arteries, and the carotid territory was supplied by each posterior communicating artery with small intracranial aneurysms. Endovascular treatment for the intracranial aneurysms was planned. However, the patient did not want to undergo the endovascular procedure because of the increased risk due to the associated bilateral carotid abnormalities. Cerebral angiography was performed again at the age of 66 years, and the size of the aneurysms had not changed. Based on their segmental identity, aplasia of segment 6 of the internal carotid artery (ICA) including the first portion of the ophthalmic artery was observed bilaterally.

Bilateral absence of the internal carotid artery and basilar aneurysm

Bilateral agenesis or hypoplasia of the internal carotid artery (ICA) is a rare anomaly of embryogenesis and the simultaneous occurrence of aneurysms is higher than in the general population. We report a 74-year-old patient presenting a spontaneous subarachnoid haemorrhage whose CT-angiography showed a basilar aneurysm and bilateral absence of the internal carotid arteries. Also bilateral hypoplastic carotid canal in the skull base was identified. Digital subtraction angiography after surgical clipping of the aneurysm confirmed the absence of the internal carotid arteries; anterior circulation was totally supplied by enlarged posterior communicating arteries.

Bilateral hypoplasia of the internal carotid artery, presenting as a subarachnoid hemorrhage secondary to intracranial aneurysmal formation: a case report

INTRODUCTION

Hypoplasia of the internal carotid artery is a rare congenital anomaly, with only 24 cases of bilateral internal carotid artery hypoplasia reported to date. Here, we present the case of a 48-year-old woman with bilateral internal carotid artery hypoplasia. She had a collateral circulation through the vertebrobasilar system; however given the high pressure flow she developed aneurysmal formations in the posterior communicating artery. To the best of our knowledge, only seven reported cases of internal carotid artery hypoplasia have been associated with intracranial aneurysmal formations.

CASE PRESENTATION

A 48-year-old Sindhi woman from Karachi, Pakistan, presented to our emergency room with a sudden onset headache and was diagnosed as having a subarachnoid hemorrhage. Digital subtraction angiography revealed hypoplasia of her internal carotid artery bilaterally with an associated fusiform aneurysm of the posterior communicating artery. Our patient declined any operative intervention in view of the associated risks. She died of a rebleed six weeks after her initial presentation.

CONCLUSION

Bilateral internal carotid artery occlusions can present with subarachnoid hemorrhages due to associated intracranial aneurysm formation. Prior knowledge about the possible existence of such angioarchitectural arrangement is mandatory for an early diagnosis. However, even with prompt diagnosis, management options with acceptable risk-benefit equations are still unavailable.