An unusual case of a giant extracranial vertebral artery aneurysm

Abstract

Objective

Extracranial vertebral artery (VA) aneurysms are rare and are often post-traumatic secondary to penetrating or blunt injuries. Primary extracranial VA aneurysms are far less common. Most of these lesions are located in the proximal (V₁) and middle (V₂) segments of the VA.

Method

We report an extremely rare case of a giant aneurysm of the extracranial vertebral artery in a 50-year-old woman who presented with a right posterior neck swelling, headache and pain at the site of the mass. Angiography confirmed aneurysm of V₃ segment of the right VA. Treatment included ligation of the artery and aneurysmectomy.

Result

Magnetic resonance angiography at 12 months showed obliterated proximal segment of the right VA with no obvious flow distally.

Conclusion

Aneurysms of the extracranial VA are clinically relevant because of the associated risks of rupture and distal embolization. For patients with rupture, pending rupture or a significant mass effect due to a giant lesion, surgery is the treatment modality of choice to attain symptomatic relief.

Keywords

Giant vertebral aneurysm surgical management

Introduction

Aneurysms of the extracranial portion of the VA are rare, and are often post-traumatic secondary to penetrating or blunt injuries.¹ Consequently, most of the reports of extracranial VA describe pseudoaneurysms. Primary extracranial VA aneurysms are far less common. They may be infective in origin or be associated with systemic diseases such as Ehlers-Danlos syndrome, neurofibromatosis, and fibromuscular dysplasia.¹ Most of these lesions are located in V₁ and V₂ segments of the VA.² Presentation varies from asymptomatic aneurysm diagnosed on routine imaging to dizziness, headaches, and neurologic deficits from cerebral ischemia or nerve compression.² Angiography remains the gold standard in diagnosis and characterization of these lesions.

Case report

A 50-year-old woman was referred to our hospital with a right posterior neck swelling that has been increasing gradually in size over a period of six years. During the few months leading up to admission, she started experiencing bouts of severe headache and pain at the site of the mass. Her medical history was notable for neurofibromatosis type 1 and essential hypertension. No other systemic illnesses, history of trauma or neck surgery. Physical examination demonstrated a pulsatile, moderately tender mass in the right suboccipital region measuring 20 × 20 cm (Figure 1). No neurological deficit was noted. Echocardiogram was normal. Duplex ultrasound revealed a right posterior neck aneurysm with a posterior haematoma suggestive of previous rupture. Angiography confirmed a large saccular aneurysm originating from the distal segment (V₃) of the right VA (Figure 2). The external and internal carotid arteries were normal. During operative intervention, proximal and distal vascular control was obtained and the aneurysm was excised. Postoperatively, there was no neurological deficit. Pathological analysis of the specimen showed a thick-walled aneurysm measuring 9.5 × 8.5 cm with organized intraluminal thrombus (Figure 3). Magnetic resonance angiography at 12 months showed obliterated proximal segment of the right VA with no obvious flow distally. An ecstatic intracranial segment of the left VA showed no significant change. The patient remained well at four years follow-up.

Figure 1.

A 50-year-old woman with a giant right vertebral artery aneurysm.

Figure 2.

Four vessel Angiogram demonstrating a large aneurysm arising from the right vertebral artery.

Figure 3.

Surgical specimen showing a thick-walled aneurysm with organized intraluminal thrombus.

Discussion

To the best of our knowledge, extracranial VA aneurysm of this size has not been reported previously in the literature. The significance of extracranial VA aneurysm lies in its life threatening complications of distal embolism and rupture. For patients with rupture, pending rupture or a significant mass effect due to a giant lesion, surgery is the treatment modality of choice to attain symptomatic relief.³ Proximal lesions are preferably treated with aneurysmectomy and vascular reconstruction whenever feasible.² Lesions of the distal vertebral artery are best treated by infraoccipital revascularization procedures, most often a carotid-to-vertebral artery bypass with vein or transposition of the external carotid artery, or by distal and proximal ligation of the vessel followed by resection of the lesion in the presence of a patent contralateral vertebral artery and normal posterior cerebral circulation.^1,3 Temporary central balloon occlusion of the vertebral artery can be useful in the latter case for preoperative assessment of the neurological outcome.⁴ Endovascular embolization has recently been shown to be safe and effective alternative to surgery in selected cases.⁵

Footnotes

Acknowledgement

The authors would like to especially thank the patient for allowing this case to be published.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

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