Aortic coarctation revealed by subarachnoid hemorrhage in a 17-year-old patient: A rare association with multiple basilar trunk aneurysms

Abstract

Aortic coarctation is a common congenital cardiovascular anomaly, usually located at the aortic isthmus. It is associated with an increased risk of intracranial aneurysms, which may rupture and lead to subarachnoid hemorrhage (SAH), particularly in the setting of long-standing proximal arterial hypertension. We present the case of a 17-year-old adolescent who was admitted with severe SAH (modified Fisher grade IV) secondary to a ruptured basilar trunk aneurysm, which was treated by endovascular coil embolization. Post-embolization investigations revealed severe arterial hypertension, prompting further vascular imaging. Thoracic computer tomography angiography showed a tight stenosis of the descending thoracic aorta consistent with postductal coarctation, with extensive collateral circulation. This case underscores the importance of considering aortic coarctation in young patients presenting with intracranial aneurysm or SAH and highlights the pivotal role of cross-sectional imaging in the diagnostic workup.

Introduction

Aortic coarctation is a relatively common congenital cardiovascular malformation, accounting for approximately 5%-8% of all congenital heart defects. It most frequently affects the aortic isthmus, just distal to the origin of the left subclavian artery. Less commonly, it may involve other segments of the descending thoracic aorta. The condition is usually diagnosed during childhood; however, milder forms may remain clinically silent and present later in adolescence or adulthood, often because of complications related to long-standing hypertension [1].

Chronic proximal arterial hypertension associated with coarctation of the aorta is considered an important contributor to intracranial aneurysm formation. In a prospective magnetic resonance angiographic study, Connolly et al. [2] detected intracranial aneurysms in 10% of patients with coarctation, a frequency significantly higher than that expected in the general population (approximately 2%) [2]. These aneurysms may present with subarachnoid hemorrhage (SAH), particularly in young patients, making early recognition of underlying etiologies crucial.

From a radiological perspective, the identification of an intracranial aneurysm in a young patient should prompt a systematic search for associated or underlying conditions. In particular, secondary causes of hypertension should be considered, including aortic coarctation, renal artery stenosis, and catecholamine-secreting tumors such as pheochromocytoma [3]. In addition, associated conditions such as autosomal dominant polycystic kidney disease should be considered because of its well-established association with intracranial aneurysms [4].

Case report

A 17-year-old previously healthy male presented to the emergency department with sudden onset of a severe headache followed by transient loss of consciousness. On admission, he was somnolent (GCS 12/15) and exhibited signs of meningeal irritation without focal neurological deficits. Noncontrast brain Computed tomography (CT) demonstrated diffuse subarachnoid hemorrhage with intraventricular extension (modified Fisher grade IV). Cerebral digital subtraction angiography identified a ruptured basilar trunk aneurysm, which was successfully treated by endovascular coil embolization.

During postprocedural monitoring, persistent severe arterial hypertension was noted despite medical therapy. Given the patient's young age, a secondary vascular cause was suspected. Thoracic CT angiography revealed severe focal coarctation of the descending thoracic aorta located 17 mm distal to the origin of the left subclavian artery. The stenotic segment had a minimal luminal diameter of approximately 4 mm and was associated with mild pre-stenotic dilatation. Extensive collateral circulation involving the intercostal, internal mammary, bronchial, and paravertebral arteries was present. Concentric left ventricular hypertrophy was also identified.

Further cerebrovascular imaging demonstrated a total of 3 aneurysms arising from the basilar artery trunk, including the ruptured aneurysm responsible for the hemorrhage. No additional intracranial vascular malformations were identified. The imaging findings were consistent with postductal aortic coarctation associated with multiple basilar trunk aneurysms. The 2 additional unruptured basilar trunk aneurysms were subsequently referred to the vascular surgery team for further management. Unfortunately, detailed information regarding their exact size, morphology, neck-to-dome ratio, presence of daughter sacs, and specific management strategy was not available in the medical records accessible to the authors (Fig. 1).

Fig. 1.

Sagittal (A) and coronal (B) reconstructions of thoracic CT angiography showing a short-segment, abrupt postductal coarctation of the descending thoracic aorta (yellow arrow and red arrow), located 17 mm distal to the left subclavian artery. (C and D) Pre-treatment cerebral angiography demonstrating a basilar trunk aneurysm, visualized as a well-defined aneurysmal sac opacifying during the arterial phase following selective injection of the vertebrobasilar circulation. (E and F) Final angiographic control following endovascular coil embolization of the basilar trunk aneurysm, showing complete occlusion of the aneurysmal sac with preservation of the parent artery and absence of residual contrast opacification.

Discussion

Intracranial aneurysms and subarachnoid hemorrhage (SAH) in young patients represent relatively uncommon but clinically important conditions. Although subarachnoid hemorrhage predominantly affects middle-aged and older adults, it also occurs in younger patients, with approximately 20% of cases reported in individuals younger than 45 years [5]. In this population, aneurysmal rupture may be associated with predisposing conditions such as hereditary connective tissue disorders, vasculopathies, infections, and secondary hypertension. This epidemiological profile emphasizes the importance of a systematic diagnostic evaluation when aneurysmal disease is identified at a young age.

Intracranial aneurysms are heterogeneous in terms of morphology and pathogenesis. Saccular (berry) aneurysms are the most common type and typically arise at arterial bifurcations exposed to increased hemodynamic stress. Blister aneurysms are rare, fragile, broad-based lesions that arise from a focal disruption of the arterial wall and are associated with a high risk of rupture and procedural complications. Infectious (mycotic) aneurysms result from infectious destruction of the arterial wall, often in the setting of infective endocarditis. Hypertensive and dysplastic aneurysms are associated with chronic vascular remodeling and medial degeneration, whereas dissecting aneurysms result from an intimal tear with subsequent intramural hematoma formation and are more frequently encountered in younger patients or those with underlying arteriopathies. Among these mechanisms, hemodynamic stress related to sustained arterial pressure elevation is particularly relevant in patients with secondary hypertension [6,7].

The pathophysiology of hypertension-related aneurysm formation is multifactorial. Chronic elevation of arterial pressure promotes endothelial dysfunction, loss of vascular smooth muscle cells within the tunica media, and fragmentation of elastic fibers. These structural changes weaken the arterial wall, particularly at arterial bifurcations within the cerebral arterial circle, where hemodynamic stress is substantial. Over time, compensatory vascular remodeling may become insufficient, resulting in focal arterial dilatation and eventual aneurysm formation. Persistent pulsatile stress may further promote aneurysm enlargement and increase the risk of rupture, particularly in patients with longstanding or poorly controlled hypertension [8].

Although the association between coarctation of the aorta (CoA) and intracranial aneurysms (IAs) has been well documented, the precise prevalence of IAs in patients with CoA remains uncertain and has not been systematically established. Previous studies have reported widely varying detection rates, ranging from 2.5% to 50%, highlighting the need for more accurate assessment of this potentially serious cerebrovascular complication [9]. A prospective magnetic resonance angiographic study by Connolly et al. [2] identified intracranial aneurysms in approximately 10% of patients with CoA, supporting the increased prevalence of IAs in this population. This association is thought to be multifactorial, with chronic proximal hypertension and altered cerebral hemodynamics considered potential contributing factors [2]. Beyond cerebrovascular complications, CoA is frequently associated with other cardiovascular abnormalities, particularly bicuspid aortic valve and left ventricular hypertrophy, as well as premature atherosclerotic changes of the proximal aorta. Extracardiac associations, including renal and genetic abnormalities, may also occur, reinforcing the importance of a comprehensive systemic assessment once the diagnosis is established [1].

Regarding the potential genetic and systemic etiology of aortic coarctation, no specific genetic testing or formal genetic counseling was documented in the available medical records. Similarly, detailed information regarding a comprehensive systemic evaluation for associated connective tissue disorders or other genetic aortopathies was not available to the authors. This represents a limitation of the present case and highlights the importance of considering genetic and syndromic evaluation in young patients presenting with CoA associated with intracranial aneurysms.

Available literature indicates that intracranial aneurysms associated with CoA may involve both the anterior and posterior circulations. Reported posterior circulation aneurysms include lesions involving the basilar tip, posterior cerebral artery, superior cerebellar artery, and posterior inferior cerebellar artery [9]. In this context, the presence of multiple aneurysms involving the basilar artery trunk in our patient represents an uncommon anatomical presentation. However, given the limited number of reported cases and the substantial heterogeneity of the available literature, no definitive predilection for either the anterior or posterior circulation can currently be established.

From a pathophysiological perspective, chronic proximal hypertension and altered cerebral hemodynamics associated with CoA may contribute to intracranial aneurysm formation through sustained vascular wall stress and abnormal flow patterns. However, current evidence remains insufficient to establish a specific hemodynamic mechanism responsible for preferential involvement of the posterior circulation or the basilar artery. In the present case, the basilar location may therefore represent an unusual anatomical distribution rather than evidence of a specific posterior circulation predilection.

Basilar trunk aneurysms present specific therapeutic challenges compared with many aneurysms of the anterior circulation. Their deep location and close relationship with numerous perforating arteries make both microsurgical and endovascular treatment technically demanding. In particular, inadvertent occlusion of perforating branches may result in brainstem ischemia and significant neurological morbidity. Endovascular approaches, including stent-assisted techniques and flow diversion, therefore require careful assessment of the perforator anatomy, parent vessel configuration, and overall aneurysm morphology. These anatomical considerations further emphasize the clinical significance of the basilar location in the present case [10].

Radiology plays a central role not only in the diagnosis and characterization of intracranial aneurysms but also in identifying their underlying systemic causes. In young patients presenting with SAH or incidentally detected aneurysms, CT angiography and MR angiography allow accurate assessment of aneurysm morphology, size, location, and rupture status. Importantly, imaging evaluation should not be restricted to the cerebral circulation [11]. A comprehensive vascular assessment may be necessary to identify systemic causes of secondary hypertension, including aortic coarctation [6]. In our case, the diagnosis of CoA was established following the investigation of persistent severe hypertension after cerebral aneurysm treatment, highlighting the pivotal role of cross-sectional imaging in detecting previously unrecognized systemic vascular disease.

On imaging, aortic coarctation typically appears as a focal narrowing of the aortic lumen, most commonly involving the aortic isthmus near the ductus arteriosus. Three anatomical patterns are classically described: preductal, juxtaductal, and postductal. In the present case, the stenosis was located distal to the origin of the left subclavian artery and was therefore classified as a postductal coarctation. The minimal luminal diameter of the stenotic segment was approximately 4 mm. Associated imaging findings included mild pre-stenotic dilatation and extensive collateral circulation involving the intercostal, internal mammary, bronchial, and paravertebral arteries. CT angiography and MR angiography are essential for pre-therapeutic assessment, providing detailed information regarding the severity and extent of the stenosis, associated aortic abnormalities, and collateral circulation, all of which are important for treatment planning.

Management of patients with intracranial aneurysms associated with CoA requires a multidisciplinary and prioritized approach. In the setting of aneurysmal rupture, securing the cerebral lesion by endovascular coiling or surgical clipping is the immediate priority because of the risk of rebleeding. Once the patient is stabilized, treatment of the underlying CoA may be considered to address the associated hemodynamic abnormalities and hypertension. Endovascular stent implantation is recommended in appropriately selected patients with significant CoA and hypertension, whereas surgical repair remains an option depending on anatomical and clinical characteristics. Balloon angioplasty alone may be considered in selected circumstances but is associated with a higher risk of intimal injury and aneurysm formation compared with stent placement [12].

Long-term follow-up is essential given the chronic nature of the vascular complications associated with CoA. Patients remain at risk of persistent or recurrent hypertension, recoarctation, and late aortic complications, including aneurysmal degeneration [12]. In addition, the association between CoA and intracranial aneurysms supports consideration of appropriate cerebrovascular surveillance in selected patients [2,12]. Strict blood pressure control remains a key component of long-term management and may help reduce cerebrovascular and cardiovascular risk [12]. Lifelong cardiovascular and cerebrovascular follow-up with individualized imaging surveillance is therefore recommended [12].

Several clinical and etiological data, including detailed blood pressure measurements, genetic evaluation, and comprehensive morphological characterization of the additional unruptured aneurysms, were not available in the records reviewed for this case. This represents a limitation of the present report and should be considered when interpreting the clinical and pathophysiological findings. In adolescents and young adults, the diagnosis of a congenital cardiovascular condition associated with intracranial aneurysms may also have a psychological impact, related to the perceived risk of neurological or cardiovascular complications and the need for lifelong medical surveillance, highlighting the importance of appropriate psychological support and patient-centered counseling.

This case highlights the importance of a multidisciplinary approach integrating neurological, cardiovascular, radiological, and vascular expertise in the diagnosis, treatment, and long-term surveillance of young patients presenting with intracranial aneurysms associated with aortic coarctation.

Conclusion

This case highlights the importance of considering aortic coarctation in young patients with intracranial aneurysm or subarachnoid hemorrhage. Early recognition of this association is vital for both neurological and cardiovascular management. Cross-sectional imaging, particularly CT angiography, plays a key role in the diagnostic workup and treatment planning.

Ethics approval

Our institution does not require ethical approval for reporting individual cases.

Patient consent

Written informed consent was obtained from the patient(s) for their anonymized information to be published in this article.