Endovascular Treatment of a Giant Subclavian Artery Pseudoaneurysm Presenting 3 Years After a Gunshot Injury

Abstract

A 29-year-old male patient presented with shortness of breath, palpitation, and back pain 3 years after a gunshot injury. Magnetic resonance imaging and selective angiography showed a giant pseudoaneurysm of the right subclavian artery. It extended into the right paratracheal and retrocaval regions, compressing the lung parenchyma. Repair was deemed mandatory because of its large size and compressive symptoms. Endovascular exclusion was performed with placement of a stent-graft device, and the patient was scheduled for subsequent surgical removal of the associated mass.

VASCULAR DISEASE MANAGEMENT 2011;8(12):E200–E202

Key words: Aortic aneurysm stent graft repair, vascular surgery

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Introduction

Subclavian artery pseudoaneurysms occur only rarely. They tend to develop as a complication of central venous cannulation and, less frequently, from chest trauma. They tend to enlarge and threaten life from potential rupture and other complications.¹ Late clinical presentation is infrequent but has been previously reported. ­

Case Report

A 29-year-old male was admitted to the cardiology outpatient clinic with shortness of breath, palpitation, and back pain. He had an operation 3 years prior because of a gunshot injury in his right chest just beneath the clavicle. After operation, he remained asymptomatic for 2 years. This first operation involved lung repair and other maneuvers, without exposure or assessment of the subclavian artery or any other major vascular structure. He then developed symptoms of progressive dyspnea and intermittent palpitations. Physical examination was unremarkable. There was no pulsatile mass in the neck or chest. Laboratory results were normal. Electrocardiography and echocardiography studies were also normal. Chest magnetic resonance imaging (MRI) was performed after seeing a large soft-tissue mass on the chest x-ray. It showed a giant saccular pseudoaneurysm originating from the right subclavian artery (Figure 1). It extended to the right paratracheal and retrocaval regions, and clearly compressed the right lung parenchyma. There was also partial compression of the superior vena cava posteriorly but without signs of superior vena cava syndrome.

The pseudoaneursym measured 8 cm in diameter and 75% of its lumen was thrombosed. The patient was evaluated initially by a cardiovascular surgeon who determined that operative therapy would be excessively risky due to the size and anatomical location of the subclavian pseudoaneurysm. Endovascular therapy was therefore planned, aiming to exclude the lesion from the main blood flow by closing off the neck at the origin from the subclavian artery. Open surgery could be performed afterwards, if necessary, to remove the surrounding mass and relieve mass effect in the chest and mediastinum.

The endovascular procedure was performed via access through the right femoral artery. The pseudoaneurysm was found (angiographically) to communicate with the main subclavian artery via a relatively large 10 mm neck that was in close proximity to the origin of the right common carotid artery. More detailed visualization of the carotid artery and innominate artery bifurcation was afforded by placement of a guidewire into the carotid artery from the left femoral artery. Endovascular exclusion of the pseudoaneurysm was achieved with deployment of a 12 x 28 mm balloon-expandable peripheral stent-graft (Jostent, Abbott Vascular) within the lumen of the right subclavian artery in the segment between the innominate artery bifurcation and the origin of the right vertebral artery. Both the carotid artery and vertebral artery orifices were spared. Completion angiography showed complete closure and exclusion of the pseudoaneurysm (Figure 2). The patient was discharged the next day without complications and a control MRI examination was scheduled 3 months later to assess the final anatomic result and determine whether additional open surgical treatment was necessary.

Discussion

Subclavian artery pseudoaneurysms are rare and tend to represent iatrogenic lesions resulting from central venous punctures.¹ Blunt or penetrating chest trauma is another important etiology. Pseudoaneurysms associated with infection, arterial anomalies, and vasculitis have also been reported.² They usually progress as rapidly growing masses at the site of injury.³ Undertaking prompt repair is crucially important to avert serious morbidity and even mortality. Symptoms are usually dependent upon the size and the localization of the pseudoaneurysm. Possible manifestations include a visible and/or palpable mass (pulsatile or not), neck pain, thromboembolic complications, compression of surrounded organs (brachial plexus, trachea, esophagus, lung, vascular structures), and subclavian steal syndrome.⁴ Surgery has been the traditional treatment choice for most cases. However, endovascular stent graft placement is gaining popularity as an alternative modality to open surgery.^5-8 It is a less invasive and possibly lower-risk approach that has been reported to produce a high degree of technical and clinical success. Major disadvantages of graft stents are closure of arterial side branches and the potential for intimal hyperplasia. 

The patient herein reported had suffered a gunshot injury 3 years prior; such late presentation of a large subclavian artery pseudoaneurysm is quite rare, if not unheard-of. The choice of an endovascular non-surgical approach (after surgical consultation) offered this patient a less invasive treatment option that was well tolerated and resulted in successful exclusion and closure of the pseudoaneurysm. He may or may not require subsequent open surgical debridement or removal of persistent mass-effect in the surrounding tissues. Technically, the procedure required detailed visualization of the pertinent vascular anatomy, with close attention being paid to protecting the carotid artery as well as the vertebral artery. Precise angiographic visualization and length measurements allowed for the right choice in terms of the length of the stent-graft device to be implanted. Endovascular catheter-based repair may well become preferred therapy in such cases in the future.

Conclusion

Late presentation of a subclavian artery pseudoaneurysm secondary to a gunshot injury has been rarely, if ever, previously reported. Endovascular stent graft exclusion of the lesion proved effective and technically sound, sparing the patient the need for a major and likely riskier open surgical operation.

References

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From the Department of Cardiology, Istanbul Medicine Hospital, Istanbul, Turkey.
Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.
Manuscript submitted August 5, 2011, provisional acceptance given August 12, 2011, final version accepted September 16, 2011.
Corresponding author: Ahmet Karabulut, MD, Istanbul Medicine Hospital, Department of Cardiology, Hoca Ahmet yesevi Cad. No:149, Gunesli-Bagcilar, Istanbul, 34203, Turkey. Email: drkarabulut@yahoo.com