Use of a Viabahn Stent for Repair of a Common Carotid Artery Pseudoaneurysm and Dissection
Article Outline
Carotid procedures in the previously operated neck are both technically demanding and subject to increased rates of complications. Adding radiation to the operated field only increases these risks. The incidence of cranial nerve injury in the reoperative neck has increased. Similarly, patients with a history of radiation are at increased risk for stroke, cranial nerve injury, and wound complications. Before the endovascular era, the only option for repair of an extracranial carotid aneurysm was open operation. Recently, more experience has been gained using endovascular techniques to repair these aneurysms. We present a patient with a history of radiation and radical neck dissection who developed a pseudoaneurysm of the common carotid artery. This pseudoaneurysm was repaired successfully using a Viabhan® covered stent graft.
Carotid procedures in the previously operated neck are both technically demanding and subject to increased rates of complications. Adding radiation to the operated field only increases these risks. The incidence of cranial nerve injury in the reoperative neck has increased.1 Similarly, patients with a history of radiation are at increased risk for stroke, cranial nerve injury, and wound complications.2, 3, 4 Before the endovascular era, the only option for repair of an extracranial carotid aneurysm was open operation. Recently, more experience has been gained using endovascular techniques to repair these aneurysms.5, 6, 7, 8, 9, 10 We present a patient with a history of radiation and radical neck dissection who developed a pseudoaneurysm (PSA) of the common carotid artery. This PSA was repaired successfully using a Viabhan® covered stent graft.
Case Report
A 65-year-old white male with a history of tobacco abuse and laryngeal cancer was referred to us. His laryngeal cancer was treated with radiation and radical neck dissection 10 years prior to presentation. Approximately 2 years prior to his presentation, the patient reported neck pain and was found to have a left common carotid artery (LCCA) dissection. Anticoagulation was initiated and the patient was observed. He did well for 2 years, but several weeks prior to presentation at our facility he complained of transient vision changes in the left eye. A carotid ultrasound confirmed the known dissection but also demonstrated an accompanying focal aneurysm in the LCCA. A computed tomography (CT) angiogram was obtained. This indicated a flow-limiting stenosis of the LCCA with thrombosis of the false lumen distally. The true lumen was narrowed to 2.8
mm. There was a PSA of the common carotid artery distally. There was concern the patient was experiencing emboli from the dissection/PSA. He was placed on clopidogrel 75mg daily. He was scheduled for a diagnostic carotid angiogram with possible angioplasty and stent placement.
Informed consent was obtained. The patient was taken to the peripheral catheterization laboratory. The procedure was performed using intravenous sedation and local anesthetic so that neurological monitoring could be performed. A standard right femoral artery approach was used. An arch aortogram was obtained, indicating the position of the great vessels. The patient was given 5,000 units of heparin intravenously prior to manipulation of the arch vessels, and activated clotting time was maintained at >275 sec. The LCCA was selected with a vertebral catheter and a stiff-angled guidewire. After selection of the common carotid artery, an angiogram was obtained. This indicated a dissection and PSA with a swirl pattern in the PSA (Fig. 1). Two-view cerebral angiograms were performed, indicating an absent anterior cerebral artery but otherwise no anatomic abnormalities. A stiff-angled guidewire was used to obtain access to the external carotid. Care was taken not to track into the false lumen. Using a long multipurpose catheter, a wire exchange to a 0.035-inch supercore wire (Guidant, Santa Clara, CA) was performed. An 8-French, 65cm sheath (Teleflex Medical, Research Triangle Park, NC) was advanced just proximal to the dissection. Before crossing the dissection, an angiogram was obtained to confirm the position in the true lumen. The dilator was replaced and the sheath and dilator were advanced past the area of dissection. No cerebral protection device was used owing to the need to use a 0.035-inch wire for placement of the covered stent graft. An 8mm×5cm Viabahn stent graft was introduced through the sheath and positioned to cover both the dissection and PSA. The sheath was withdrawn to expose the stent. The distal landing zone was just proximal to the bulb region. Follow-up imaging indicated complete exclusion of the aneurysm with brisk flow maintained into the internal and external carotid arteries (Fig. 2). There was good reexpansion of the true lumen. No postdilation was required. Completion cerebral angiograms were obtained and demonstrated no changes. The sheath was removed over the supercore wire. The patient was observed overnight. He was neurologically intact the next morning and discharged on clopidigrel 75mg daily.
Fig. 1
Initial angiogram indicating carotid aneurysm. Note swirl pattern.
Fig. 2
Completion angiogram indicating complete exclusion of aneurysm.
Discussion
Extracranial carotid aneurysms are quite rare. El-Sabrout and Cooley11 encountered only 67 aneurysms of the extracranial carotid artery in their 35-year experience of 7,394 aortic and peripheral aneurysms at Texas Heart Institute in Houston, Texas. They noted that the vast majority of these were either pseudoaneurysmal or resultant from previous patch angioplasty (37 of 67) or atherosclerotic degeneration (23 of 67). Our patient presented with a PSA that was likely the result of a radiation-induced carotid dissection. Until quite recently, this patient would have required an open intervention in a previously operated, irradiated field. Potential complications can include wound infection, aneurysmal degeneration of the repair site, increased risk of stroke, and significantly increased risk of cranial nerve injury.1, 2, 3, 4, 10 In addition, an open repair may have required a venous conduit. This may or may not be available in all cases. If required, flap coverage would be difficult and fraught with additional risks of complications.
A Viabahn heparin-coated stent graft was used in this case. In addition to its ease of deployment and proven track record in peripheral vessels, it has a lower profile and greater flexibility than other covered stent grafts. We also felt a self-expanding stent was more suitable for use in a compressible area such as the neck. Cerebral protection was not used in this case. Although it is possible to place a protection device, the smaller 0.014-inch guidewire does not provide sufficient support to place the currently available covered stents. In addition, the Viabahn stent graft and other covered stents of sufficient cross section are designed to track over 0.035-inch wires. An unacceptable risk of further damage to the intima exists from a “snowplow” effect secondary to the wire/device size mismatch. The patient was placed on clopidogrel prior to the procedure and will remain on antiplatelet therapy. We feel that this will reduce the risk of embolic events related to placement of a covered stent graft.
There have been several case reports dealing with covered stents in the carotid circulation for a variety of indications.5, 6, 7 Zhou et al.10 presented their experience with carotid artery aneurysms between 1984 and 2004. In addition to reduced hospital stay, they found decreased rates of cranial nerve injury, wound infection, and stroke as their use of endovascular repair increased. Bush et al.8 reported 100% successful aneurysm thrombosis with no neurological events in their small series of five patients. Yi et al.9 reported similar success rates for occlusion and patency in their series of 10 patients. Given this growing body of evidence, we feel endovascular stent-graft repair of the carotid artery aneurysm and PSA is emerging not only as an excellent alternative to open surgery but in many cases should be considered first-line therapy.
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PII: S0890-5096(09)00324-0
doi:10.1016/j.avsg.2009.07.037
Published by Elsevier Inc.
