Endovascular treatment of an iatrogenic right subclavian artery pseudoaneurysm associated with an arteriovenous fistula

Abstract

This report describes the case of a frail 36-year-old patient who underwent an endovascular treatment of a right subclavian artery pseudoaneurysm (SAP) associated with an arteriovenous fistula secondary to a traumatic central venous catheter insertion. The deployment of a covered stent from the innominate to the right common carotid artery combined with coiling of the SAP and the internal mammary artery was performed. Two additional covered stents were deployed from the vertebral artery to the distal subclavian artery to preserve right upper extremity circulation. This case highlights the feasibility of an endovascular treatment of a complex SAP in a candidate unsuitable for open surgery.

Central venous catheters (CVCs) are used commonly in the treatment of acutely ill patients for volume resuscitation, administration of drugs, hemodynamic monitoring, and dialysis. Even though the placement of CVC is considered safe, complications may occur in 4% to 35% of cases.¹ Despite most CVC placements being nonconsequential, inadvertent arterial puncture may result in adverse events, such as arteriovenous fistula, arterial dissection, hematoma, pseudoaneurysm, and stroke.² Iatrogenic pseudoaneurysm after CVC placement has an incident rate of 0.05% to 2.00%.³ The literature reporting iatrogenic SAP consists of few case reports.4, 5, 6 Open surgical procedures including direct repair, ligation, or bypass are the most commonly described treatment, although, in high-risk patients, endovascular interventions or thrombin injections have been described as safe options.⁶ In this case report, we describe a strategy involving the placement of covered stents and coiling to exclude an SAP. Patient consent was obtained for the publication of the enclosed content and images.

Case Report

A 36-year-old man presented to our tertiary care center in October 2022 in cardiogenic shock secondary to a giant cell myocarditis. Owing to the rapid decline in his cardiac function (left ventricular ejection fraction of 15%), the patient was placed on extracorporeal membrane oxygenation and was transferred to a cardiac transplantation center temporally for left and right ventricular assistance. His hospitalization was complicated by acute renal failure requiring hemodialysis, which required the placement of a right internal jugular 12F dialysis catheter. A tracheostomy was also performed because of a prolonged intubation. After 2 weeks, his general condition improved, leading to cardiac assistance removal and his transfer back to our center in a stable state with minimal ventilatory parameters.

Upon arrival to our intensive care unit, it was noted on physical examination that there was an important pulsatile mass associated with a thrill in zone 1 of the right cervical region, next to the dialysis catheter, which was in place and functional. When the vascular surgery service was consulted, the patient was afebrile, with normal vital signs. An axial thoracic computed tomography angiogram (CTA) revealed the presence of a 3.9 × 3.0 × 6.0 cm pseudoaneurysm of the right subclavian artery with the most posteroinferior portion communicating with the internal jugular vein (Fig 1). Three-dimensional reconstructions were performed to assess the anatomy (Fig 2, A and B). All supra-aortic vessels were patent, and the codominant vertebral arteries (VAs) equally contributed to the basilar artery. The SAP was extending from <4 mm distal to the origin of the subclavian artery to 5 mm proximal to the right VA origin (Fig 3). There were no signs of active bleeding or hematoma. The dialysis catheter was located at the superior level of the SAP and entered at the confluence of the brachiocephalic veins.

Fig 1.

Initial computed tomography angiography (CTA) demonstrating the arteriovenous fistula between the right internal jugular vein and the right subclavian artery

Fig 2.

(A) Three-dimensional reconstruction demonstrating a lateral view of the origin of the right vertebral artery (VA) in relation to the pseudoaneurysm. (B) Three-dimensional reconstruction demonstrating an anterior view of the pseudoaneurysm and the origin of the right subclavian artery.

Fig 3.

Sizing sheet of the right subclavian pseudoaneurysm.

Open surgical options for a proximal SAP would have required a partial or total sternotomy. Considering the poor cardiac function of the patient, a minimally invasive approach was necessary. A hybrid approach involving a carotid-subclavian or axillary bypass was deemed too risky for infection with the presence of a tracheostomy. A simple subclavian artery covered stent placed across the arterial defect would not have guaranteed sufficient sealing between the origin of the subclavian artery and the beginning of the SAP, because its length was too short. Kissing stents were considered, but the authors were concerned that the smaller stent, which would be the carotid stent, would have been compressed and at risk of thrombosis. Thrombin injection was contraindicated because of the pseudoaneurysm's large neck and the risk of pulmonary embolism related to the arteriovenous fistula. After a multidisciplinary discussion, an endovascular strategy was deemed the best therapeutic option considering the diameter discrepancy between the arteries and the precarious condition of the patient. Therefore, the patient was booked for an intervention 10 days after readmission considering there was no indication for an urgent intervention and the patient was still improving from his complex medical condition.

Under general anesthesia, a left percutaneous common femoral artery access and a right open high-brachial artery access were performed. The patient received 5000 U intravenous heparin. Angiography (Fig 4) was performed before deploying a VBX-8Lx59 mm (W. L. Gore & Associates, Flagstaff, AZ) covered stent from the innominate trunk to the right common carotid artery. This stent was chosen because of its ability to be postdilated up to 16 mm and molded at different diameters in the proximal and distal segments. Owing to the mismatch in diameters between the innominate trunk and the common carotid artery, a 12-mm noncompliant balloon was used to obtain an adequate sealing in the innominate artery. The structure of the stent also allowed for minimal foreshortening with postdilatation. From the right brachial access, the right internal mammary artery was catheterized and embolized with 3-mm coils. The right proximal subclavian artery and the pseudoaneurysm were then coiled with large diameter coils (18-20 mm). Finally, the right VA was catheterized and 5 × 28 and 6 × 22 mm BeGraft Peripheral Stent Graft (Bentley InnoMed, Hechingen, Germany) were deployed with the dual objective of having a distal seal in the subclavian artery to totally exclude the aneurysm while maintaining perfusion to the arm from the retrograde flow of the patent VA. A final angiogram demonstrated patency of the stents and absence of an endoleak (Fig 5, A and B). Finally, distal Doppler signal, pulse oximetry, and capillary refill confirmed an adequate perfusion of the hand. The patient's postoperative course was uneventful, without upper extremity ischemia or claudication. A new hemodialysis catheter was installed in the left internal jugular vein and the right one was retrieved with an angiogram demonstrating the resolution of the fistula. Postoperative CTA performed 3 days later confirmed technical success. The tracheostomy was closed 8 weeks later and the patient was discharged home 3 months later. At the 6-month follow-up, the patient remains asymptomatic. A right radial pulse was palpated, while a systolic blood pressure differential of 24 mm Hg between both upper extremities was present.

Fig 4.

Angiogram of the right subclavian pseudoaneurysm.

Fig 5.

(A and B) Final angiogram after covered stenting of brachiocephalic-to-right-carotid artery and coil embolization of the proximal right subclavian artery demonstrating adequate exclusion of the pseudoaneurysm (A) and adequate perfusion of the right subclavian and axillary artery by the retrograde flow from the vertebral artery (VA) (B). (C and D) Final computed tomography (CT) scan after the intervention demonstrating the stenting of the brachiocephalic-to-right-carotid artery (C) and the stenting of the right VA to the right subclavian artery (D).

Discussion

Iatrogenic subclavian artery pseudoaneurysms (SAPs) are a relatively rare phenomenon, but they are highly suspected based on clinical findings of a pulsatile mass, hematoma, hemodynamic instability, and/or compressive or ischemic symptoms. A CTA is essential to confirm and describe the characteristics of the SAP.⁷ When an arterial complication occurs, the management should be tailored to the patient's anatomy and condition.⁶ According to Guilbert et al.,¹ catheters of <7F located in compressible areas of the neck can be removed safely; otherwise, an intervention should be considered, In this case, a simple pull/pressure technique was not an option considering the CVC size (12F), the presence of a large pseudoaneurysm and its proximal localization. Open repair would have required a median sternotomy or thoracotomy to obtain a proximal control. To minimize the procedure's risks, a reasonable hybrid alternative could have implied a right carotid-to-subclavian artery bypass followed by an innominate-to-carotid artery covered stenting with coiling of the vertebral and distal subclavian arteries. However, the infectious and cardiac risk assessment associated with the tracheostomy and poor cardiac function of our patient were deemed prohibitive for open repair.

To our knowledge, vertebral to distal subclavian artery stenting has not been described for the treatment of an iatrogenic arterial injury. The main benefit of this configuration was to maintain a major inflow to the upper extremity coming from the retrograde VA. If an embolization alone of the subclavian artery had been chosen, blood supply from collateral network could have been insufficient, which would have required an urgent extra-anatomic bypass in a nonideal timeline. We considered our strategy more predictable in potentially decreasing the risk of immediate arm ischemia associated with an acute occlusion of the subclavian artery.

Considering the large size of the pseudoaneurysm, prompt treatment was necessary. In the patient's specific anatomy and situation, the complex endovascular repair described in this report was considered a safe option.

Conclusions

A novel combination of covered stenting and coiling was used to exclude a complex SAP combined with an arteriovenous fistula in a high-risk patient for open repair. Patients could benefit from advanced endovascular treatment, although long-term outcomes need to be assessed.

Disclosures

None.