Endovascular Treatment of Traumatic Carotid Pseudoaneurysm with Stenting and Coil Embolization
Article Outline
Posttraumatic internal carotid pseudoaneurysm is an infrequent but potentially life-threatening condition that complicates approximately one-third of blunt carotid injuries. Other types of injuries include dissection, thrombosis, and complete disruption. Historically, carotid pseudoaneurysms have been managed operatively with repair, ligation, and anticoagulation, with percutaneous angioplasty and stenting emerging over the past decade. We present the case of a 19-year-old patient with a posttraumatic internal carotid pseudoaneurysm that increased in size with conservative management and was treated with coil embolization and stenting.
Though an uncommon complication following blunt carotid trauma, pseudoaneurysm formation is associated with a significant risk of morbidity and mortality.1 Repair of carotid pseudoaneurysms is usually required because of the potential for rupture and distal embolization as they often contain thrombus. In addition, pseudoaneurysms may cause symptoms by compressing adjacent structures.2 The conventional treatment includes surgical excision and arterial reconstruction with vein or synthetic graft. Recently, the use of endovascular stents has emerged as an alternative treatment for posttraumatic or anastomotic carotid pseudoaneurysms in efforts to decrease the morbidity associated with open surgical repair. This report describes a case of a posttraumatic internal carotid pseudoaneurysm that was initially treated with anticoagulation and subsequently embolized and excluded with a bare metal stent.
Case Report
An otherwise healthy 19-year-old woman was evaluated for a posttraumatic asymptomatic internal carotid pseudoaneurysm. She was involved in a motor vehicle collision 6 months prior to presentation and had required a splenectomy and distal pancreatectomy at an outside institution, from which she had completely recovered. She was noted to have bilateral papillary dilatation and right facial drooping when first evaluated in the trauma bay; however, this spontaneously resolved within minutes with no residual deficit. Subsequent workup included computed tomographic (CT) scan of the head, which showed no intracranial injuries, as well as CT angiogram (CTA) of the neck and carotid duplex ultrasound, both of which showed evidence of bilateral internal carotid dissection and pseudoaneursym formation. Heparin anticoagulation was instituted, and the patient was eventually discharged home on warfarin. Follow-up CTA at 4 months showed resolution of the left-sided pseudoaneurysm and increase in size of the right-sided pseudoaneurysm.
After evaluation on the current presentation, a four-vessel arch angiogram and selective carotid views were obtained, confirming the presence of a distal internal carotid pseudoaneurysm on the right (Fig. 1), with no contralateral lesions. In the operating room angiography suite, using a fixed imaging system (Siemens, Munich, Germany), endovascular exclusion was performed 2 weeks later. Right common femoral access was used to access the right internal carotid artery following systemic heparinization, using a 0.035-inch stiff angled guidewire (Terumo, Somerset, NJ), an angled glide catheter (Angiodynamics, Queensbury, NY), and a 6-French Raabe sheath (Cook, Bloomington, IN) that was positioned in the common carotid artery. A 5 × 20 mm balloon (Gazelle; Boston Scientific, Natick, MA) was then inflated in the internal carotid artery over a 0.014-inch wire for 15 min to monitor for the development of neurological intolerance in the event thrombosis were to complicate pseudoaneurysm exclusion. This was well tolerated, and the decision was made to proceed with the planned intervention. Left common femoral puncture was then used to access the pseudoaneurysm with a 0.035-inch stiff angled guidewire, followed by a Renegade microcatheter (Boston Scientific) (Fig. 2). A 5 × 20 mm Acculink bare metal stent (Guidant, Santa Clara, CA) was then deployed across the neck of the pseudoaneurysm over a 0.014-inch wire. The microcatheter left in the pseudoaneurysm sac was used to deliver a 5 × 10 mm Tornado platinum coil (Cook). Completion angiography showed complete exclusion of the pseudoaneurysm (Fig. 3). The patient was discharged home the following morning on 1 month of clopidogrel and continues to be neurologically intact at 2-year follow-up. Stent patency was confirmed on Duplex carotid ultrasound postoperatively at 6 months, 1 year, and 2 years, with complete exclusion of the pseudoaneurysm.
Fig. 1
Selective right carotid injection, confirming the presence of a distal internal carotid pseudoaneurysm.
Fig. 2
Setup utilized prior to deployment of the stent across the base of the pseudoaneurysm, with a 0.035-inch stiff angled guidewire, a Renegade microcatheter positioned in the pseudoaneurysm, and a 0.014-inch wire in the internal carotid artery.
Fig. 3
The microcatheter left in the pseudoaneurysm sac was used to deliver a 5 × 10 mm Tornado platinum coil. Completion angiography showed complete exclusion of the pseudoaneurysm.
Discussion
Many individuals with blunt carotid injury are asymptomatic initially and may first present with a neurological deficit.1 Patients who therefore present with or develop neurological deficits and whose cerebral CT scans do not account for these deficits should undergo further investigation. The majority of posttraumatic blunt carotid injuries are best treated with anticoagulation, as reported in the trauma literature.1 This mainly applies to carotid dissections since up to 62% will revert to normal on follow-up angiograms.1 Pseudoaneurysms, however, are unlikely to spontaneously resolve,1, 3 and up to 29% of carotid dissections may result in pseudoaneurysm formation.1
Individuals with pseudoaneurysms may present with neurological symptoms weeks, months, or even years later.3, 4 This, along with the limitations of conservative management, is evidence for intervention following the initial diagnosis of a carotid pseudoaneurysm. The potential interventions include surgical repair, surgical ligation, and endovascular exclusion. However, inaccessible pseudoaneurysms have been managed by anticoagulation and proximal ligation with and without extracranial–intracranial bypass. Although the best definitive management remains unclear, endovascular exclusion is an attractive alternative in anatomically difficult situations.
Use of covered stents, bare metal stents, and vein-covered stents has been reported in the literature.5 Most series, however, provide little long-term follow-up data.
Even though the small number of cases of both post-carotid endarterectomy and traumatic carotid pseudoaneurysms does not provide the statistical power with which one can draw definitive conclusions, review of the literature raises several cautionary flags that should be considered before using covered stents in the carotid circulation for pseudoaneurysm repair.5 Although stent grafting of carotid pseudoaneurysms is currently an accepted treatment modality, it remains to be seen whether the incidence of covered stent occlusion should suggest their avoidance in repairs of the cerebral or carotid circulation, where the consequences of acute occlusion can be devastating or fatal. The use of an endovascular balloon test occlusion prior to stent deployment may provide characterization of the outcome of acute occlusion,6 as was performed in the current case; however, the reliability of such a test is unknown.
In addition to deploying endoluminal stents to exclude pseudoaneurysms, Bush et al.7 embolized the pseudoaneurysms by injecting coils through microcatheters through the interstices of the stents. The authors also recommended that the external carotid artery be embolized before stent placement if the pseudoaneurysm involves the external carotid artery. We did not embolize the external carotid artery, and the pseudoaneurysm thrombosed, as documented on early and late postoperative duplex scans. The use of smaller microcatheters, such as the Turbo-Tracker catheter (Boston Scientific) is recommended to avoid coil impaction and may be advantageous if coiling is performed through the interstices of the stent.
Self-expandable stents, as used in this case, have gained favor over balloon-expandable stents due to their flexibility and shape memory, minimizing the potential for collapse and deformation. Their use for traumatic carotid pseudoaneurysms without coiling has been successfully reported in small case series.8
Though several case reports have described the technical success achieved with endovascular stents for the treatment of carotid pseudoaneurysms, the relative infrequency of endovascular cases does not currently allow for determination of complication rates, durability of stents, or optimization of a postoperative regimen, especially in younger patients as described in this report.
We did not use a cerebral protection device because we believed the risk for cerebral embolization was low in the absence of atherosclerotic disease. In addition, no filling defects were noted on angiograms obtained before stent placement. While we cannot substantiate our opinion, it is probably prudent to use cerebral protection devices in patients with large pseudoaneurysms since they are likely to contain a large amount of thrombus. Although there is a theoretical benefit for cerebral protection during coil embolization, coil dislodgement during deployment has not been a limiting concern.
The role of anticoagulation therapy after stent placement is speculative. We gave our patients clopidogrel for 6 weeks afterward, as is the practice following carotid angioplasty and stenting for carotid occlusive disease. Despite the paucity of data to substantiate our opinion, we think these patients should receive clopidogrel for 4-6 weeks after stent placement and should not require warfarin sodium.
Conclusion
Endovascular exclusion of posttraumatic carotid pseudoaneurysms with a bare metal stent and coil embolization is technically feasible and safe. It should be considered in technically difficult situations, such as in reoperative cases or high inaccessible lesions. Cerebral protection devices may be of benefit if imaging studies demonstrate thrombus within the pseudoaneurysm. Closed cell stents have been used without coiling for traumatic pseudoaneurysms, and stent grafts have been used for traumatic and postoperative carotid pseudoaneusyms but with limited experience. Concerns about the long-term patency of these stents in the carotid artery position remain, and close follow-up with duplex surveillance should be emphasized.
References
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PII: S0890-5096(08)00039-3
doi:10.1016/j.avsg.2008.01.006
© 2008 Annals of Vascular Surgery Inc. Published by Elsevier Inc All rights reserved.
