Heparin Surface Stent-Graft for the Treatment of a Carotid Pseudoaneurysm
Article Outline
Carotid pseudoaneurysms are a rare consequence of carotid surgery, trauma, and infection. Historically, carotid aneurysms and pseudoaneurysms were treated surgically. However, endovascular techniques have recently become a valid alternative for the treatment of carotid pseudoaneurysms.
The case of a 57-year-old male patient with a pseudoaneurysm of the right internal carotid artery is described. The patient came to our unit with a painless and pulsatile mass in the neck, which was growing slowly. Five years earlier, he had undergone surgery on a saccular aneurysm located on the distal extracranial segment of the right internal carotid artery. The pseudoaneurysm was successfully treated with a heparin surface Viabahn stent-graft system (Gore AL, Flagstaff, AZ).
Heparin surface stent-grafts can be used for the treatment of carotid lesions and may offer protection against intimal hyperplasia and thrombosis. Further studies are needed to evaluate the long-term results.
Carotid pseudoaneurysms occur after carotid artery surgery, traumas, neck surgery, and infections.1, 2 They are usually painless, continue to grow slowly, and manifest as a pulsatile mass in the neck.3 However, they can manifest with more severe symptoms such as hemorrhage caused by rupture or with neurological symptoms caused by cerebral embolization.4, 5 Although historically carotid aneurysms and pseudoaneurysms were treated surgically,6 covered stents or stent-grafts have become a recent alternative treatment for this pathology with encouraging mid-term results. This case report describes the use of a covered stent to treat a carotid pseudoaneurysm. We believe that the use of a covered stent with a heparinized surface may have advantages as compared with other stents, in terms of decreasing the risk of thrombosis and perhaps intimal hyperplasia.
Methods
A 57-year-old man came to our unit with a painless, progressively growing and pulsating neck mass. Five years earlier he had undergone surgery to remove a saccular aneurysm located on the distal extracranial segment of the right internal carotid artery (ICA). The treatment consisted of aneurysmectomy and end-to-end anastomosis. His medical history was unremarkable and he did not show signs of dysphagia, fever, respiratory difficulties, or central neurological symptoms such as transient ischemic attack or stroke.
The ultrasound examination showed a partially thrombosed pseudoaneurysm, involving the third distal extracranial segment of the right ICA. It measured 40 × 60 mm and was caused by a dehiscence of the surgical anastomosis. The head and neck computed tomography angio scan confirmed the ultrasound findings (Fig. 1).
Fig. 1
Preoperative computed tomography angio scan showing the carotid pseudoaneurysm (arrow).
Urgent endovascular management was proposed and the patient gave his informed consent after the potential risks and benefits of the proposed treatment had been explained to him. The patient was not administered clopidogrel before surgery. In the operating theatre, after administration of 5,000 units of heparin, a selective angiogram of the carotid bifurcation was performed through a right femoral percutaneous access under local anesthesia. A 0.035 in guidewire (Implants Super stiff, Boston Scientific, Natick, MA) was placed in the external carotid artery after a 7F introducer sheath was placed in the common carotid artery and a road map was obtained to localize the lesion more precisely. After catheterization of the ICA by a 0.035 in Terumo guidewire (Terumo Medical Corporation, Japan), a 5 mm × 2.5 cm Viabahn stent-graft with heparin surface (Gore AL, Flagstaff, AZ) was placed on the ICA to cover the dehiscence (Figs. 2A, B). No cerebral protection device was used because there was no evidence of atherosclerotic lesions or dissection. The completion angiography demonstrated an endoleak caused by incomplete expansion of the stent-graft, which was successfully treated by dilation with an angioplasty balloon catheter (Ultrasoft 5 × 2 mm, Boston Scientific, Natick, MA). The final angiography showed the complete exclusion of the pseudoaneurysm and patency of the carotid arteries (Fig. 2C). An Angio-seal closure device (St. Jude Medical St. Paul, MN) was used to seal the femoral artery puncture.
Fig. 2
A Preprocedure angiography showing the right ICA pseudoaneurysm (arrow). B Intraoperative angiography highlighting the presence of an endoleak as the stent-graft did not fully expand. C Final intraoperative cervical and cerebral angiography showing exclusion of the pseudoaneurysm after stent-graft expansion and patency of the carotid arteries.
The postoperative stage was uneventful and the patient was discharged on the second postoperative day with double antiplatelet therapy (clopidogrel, 75 mg; aspirin, 325 mg).
Clinical and ultrasound follow-ups were performed, as well as angiography, 1, 3, and 6 months postoperatively. They showed complete exclusion of the lesion and patency of the ICA, with no evidence of stenosis or intimal hyperplasia (Figs. 3A-C).
Fig. 3
A, B Three-month ultrasound examination showing complete thrombosis and exclusion of the lesion as well as hypertrophic branches of the external carotid artery passing under the pseudoaneurysm B (arrow). C Three-month angiographic control confirming patency of the internal carotid artery.
Discussion
Carotid pseudoaneurysms occur after carotid artery surgery, traumas, neck surgery, and infections.1 Surgical treatment is not always feasible, especially when lesions are situated near the base of the skull, because of difficult exposure, distal vascular control, and the high rates of associated cranial nerve injuries (3-13%).
Recently, endovascular techniques have become a valid alternative for the treatment of carotid pseudoaneurysms. Hoppe et al. report encouraging short- and mid-term results after stent-graft placement in cases of carotid aneurysms, pseudoaneurysms, and carotid blowout syndrome.7 However, distal embolization,8 stent thrombosis, dissection, and restenosis are some of the most severe complications following carotid stenting, even when antiplatelet therapy is administrated.9 It is believed that intimal injury of the artery during carotid stenting triggers platelet activation and aggregation, as well as the inflammatory cascade with subsequent smooth muscle proliferation. Furthermore, thrombus formation immediately after carotid stenting and embolization to distal sites can cause serious postprocedural complications. The most important factors contributing to stent thrombosis include the small size of the vessel, stent under-dilation, and the presence of proximal or distal dissection.10 Chaturvedi et al. and McKevitt et al.11, 12 suggest that double antiplatelet therapy after carotid stenting plays an important role in reducing adverse neurological outcomes without further complications of increased bleeding.
With our patient, the decision to give him endovascular treatment was based on the perceived difficulty of exposing the ICA because of previous surgical repair and the distal extent of the lesion. Thus, placement of a short, self-expanding stent-graft was considered an applicable and minimally invasive therapeutic approach as the pseudoaneurysm was caused by dehiscence on the ICA anastomosis. The choice of a heparin-surface stent was based on the possibility of additional protection against intimal hyperplasia and thrombosis. In the published data, different studies report successful carotid aneurysm or pseudoaneurysm exclusion after placement of a Viabahn stent-graft. However, little has been published on the use of human carotid pseudoaneurysm being treated with a heparin surface stent-graft.13
In conclusion, heparin surface stent-grafts may be used for the treatment of carotid lesions and they offer additional protection against intimal hyperplasia and thrombosis. Further studies are needed to evaluate the long-term results for this new device.
References
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PII: S0890-5096(10)00144-5
doi:10.1016/j.avsg.2010.02.046
© 2010 Annals of Vascular Surgery Inc. Published by Elsevier Inc All rights reserved.
