Initial Management
Cervical spine immobilization, which is usually appropriate, should be performed in the setting of any significant traumatic injury that could involve the neck.
Patients with internal carotid artery dissection may present to the emergency department (ED) in various ways and with various nonspecific complaints, but in all cases, the emergency physician should maintain a high index of suspicion. If internal carotid artery dissection is included in the differential diagnosis, the possibility should be pursued until it is clinically ruled out.
Depending on the likelihood of dissection, patient characteristics, neurologic status, and hemodynamic stability, medical management may occur during the diagnostic process or after the diagnosis is made. As in all medical care decisions, the benefits of treatment must be carefully weighed against the risks. Input from endovascular and surgical consultants should facilitate management decisions.
Initial computed tomography (CT) of the head is usually warranted, depending on the patient’s presentation. If the scan yields negative results or the findings do not correlate with the patient’s symptoms and signs, it should be followed up by a more definitive imaging modality, such as magnetic resonance angiography (MRA), CT angiography (CTA), or conventional angiography (depending on institutional preferences; see Workup).
In a prospective study that used repeated MRI over 6 months to investigate spatial and temporal dynamic changes of intramural hematomas in 10 patients with acute spontaneous internal carotid artery dissection, Heldner et al found an early postdissection volume increase with progression of the internal carotid artery stenosis in five patients. [20] Overall, spontaneous internal carotid artery dissection had a good prognosis with spontaneous hematoma resorption in all of the investigators’ patients, but early follow-up imaging may be considered, particularly in the case of new clinical symptoms.
Pharmacologic, Endovascular, and Surgical Therapy
There is no general consensus regarding optimal management of internal carotid artery dissection, but the choice among medical, endovascular, [21] and surgical options may depend on the type of injury, the anatomic location, the mechanism of injury, coexisting injuries, and comorbid conditions. Therefore, after the diagnosis is made, the risk-to-benefit ratio of antithrombotic therapy should be determined, especially in cases of high-impact trauma, and vascular surgery or interventional radiology consultations should be obtained.
Anticoagulant therapy should be initiated when a thrombus is detected. Anticoagulation with intravenous (IV) heparin followed by warfarin has generally been accepted as adequate medical management for preventing thromboembolic complications. Do not initiate anticoagulation in trauma patients without first ruling out intracranial hemorrhage (ICH) and extracranial sources of hemorrhage.
Antiplatelet therapy has also been used alone, especially when systemic anticoagulation is contraindicated. Do not initiate either anticoagulation or antiplatelet therapy in pregnant patients without consulting an obstetrician.
Candidates for angioplasty and stent placement include patients with persistent ischemic symptoms despite adequate anticoagulation, patients with a contraindication to anticoagulant therapy, patients with an iatrogenic dissection developing during an intravascular procedure, and patients with significantly compromised cerebral blood flow. [21, 22, 23]
Surgery has a limited role in the management of carotid artery dissections. The usual complications associated with surgical or endovascular procedures may occur if such procedures are employed in the early management of the dissection.
Nonetheless, a literature review study by Xianjun and Zhiming indicated that in selected patients, internal carotid artery dissections can be effectively managed with stenting or stent-graft-supported angioplasty. [21] The review included 201 patients who suffered traumatic, spontaneous, or iatrogenic internal carotid artery dissection. Endovascular treatment of these patients had a 99.1% technical success rate, with no procedure-associated mortality reported.
Perioperatively, there was an overall rate of major cardiovascular events of 4% in this review, and postoperatively, over a mean 16.5-month follow-up period, the rate of intimal hyperplasia or in-stent restenosis or occlusion was 3.3%. [21] Over a mean 20.9-month follow-up period, recurrent transient ischemic attack in the treated vessel’s territory occurred in just 2.1% of patients.
In a study of 18 selected patients with extracranial internal carotid artery dissection, Juszkat et al found carotid artery stenting to be safe and effective. [24] In all patients, stent deployment immediately restored flow in the true lumen of the internal carotid artery. Complete resolution of clinical symptoms was observed in 14 patients (78%), partial improvement in two (11%), and persistence of neurologic deficit in only two (11%).
Consultations
For each patient with carotid artery dissection, the risks and benefit of initiating antithrombotic therapy must be assessed. Consultation with one or more of the following services may be useful, particularly in difficult situations such as multiple trauma, traumatic brain injury, preexisting brain lesion, or upper gastrointestinal bleeding:
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Neurology
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Vascular surgery
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Neurosurgery
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Interventional radiology
Long-Term Monitoring
Patients should be closely monitored for delayed ischemic or embolic neurologic symptoms and for the hemorrhagic side effects of antithrombotic medication. Ischemic stroke, mainly from thromboembolic complications of the initial dissection, may occur. Hemorrhagic stroke may occur secondary to anticoagulant use in some patients.
If anticoagulation is initiated, it should be continued for 3-6 months with appropriate follow-up for international normalized ratio (INR) and prothrombin time (PT) monitoring. The target range for the INR should be 2.0-3.0. Follow-up with CTA, Doppler ultrasonography (DUS), or another angiographic imaging modality should be done several months after the event to reevaluate the dissection. Dissection may recur in the unaffected artery; the incidence of this development may be higher than 1% per year in patients with a known heritable arteriopathy.
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Arterial dissection. (A) Tear and elevation of intima from wall of artery, resulting in luminal stenosis. Illustration shows stasis of flow in false lumen beneath elevated intima. This condition creates blind pouch that predisposes patient to thrombus formation. (B) Subadventitial dissection represents hemorrhage between media and adventitia. Artery may become dilated as result of thickening of arterial wall, with some degree of luminal narrowing. Elevation of intimal flap is not commonly associated with this type of dissection. Hemorrhage may extravasate through adventitia, resulting in pseudoaneurysm or fistula formation.
