What are the latest guidelines for managing a patient with an Internal Carotid Artery (ICA) dissection?

Management of Internal Carotid Artery Dissection

For patients with ICA dissection, initiate antithrombotic therapy immediately—either antiplatelet therapy (aspirin 81-325 mg daily or clopidogrel 75 mg daily) or anticoagulation (heparin followed by warfarin)—for 3-6 months, followed by long-term single antiplatelet therapy. 1, 2

Diagnostic Approach

Imaging modalities for diagnosis:

• CT angiography, MR angiography, or catheter-based contrast angiography are the recommended diagnostic tools (Class I recommendation) 1, 2
• Duplex ultrasound may miss dissections originating above the jaw angle, limiting its utility as a standalone diagnostic test 2
• Look for the characteristic "string sign" (tapered narrowing), intimal flap, or intramural hematoma on cross-sectional imaging 1

Medical Management

Antithrombotic Therapy (First-Line Treatment)

Initial 3-6 month treatment period:

• Either anticoagulation OR antiplatelet therapy is reasonable (Class IIa recommendation) 1, 2
• Anticoagulation options: heparin or low-molecular-weight heparin followed by warfarin 1
• Antiplatelet options: aspirin (81-325 mg daily), clopidogrel (75 mg daily), or extended-release dipyridamole plus aspirin 1, 2
• No definitive evidence favors anticoagulation over antiplatelet therapy—both are considered acceptable first-line options 1, 2

After 3-6 months:

• Transition to long-term single antiplatelet therapy with aspirin (81-325 mg daily) or clopidogrel (75 mg daily) 2

Blood Pressure Management

• Antihypertensive medication to control blood pressure and reduce arterial wall stress is recommended 2
• Beta-blockers, angiotensin inhibitors, or non-dihydropyridine calcium channel blockers (verapamil or diltiazem) may be considered, though their safety and effectiveness are not well established (Class IIb recommendation) 1, 2

Endovascular Intervention

Indications for carotid angioplasty and stenting:

• Consider endovascular therapy when ischemic neurological symptoms persist or worsen despite antithrombotic therapy (Class IIb recommendation) 1, 2
• Also reasonable for patients with expanding pseudoaneurysms, severe flow compromise, or contraindications to anticoagulation 3, 4
• Embolic protection devices during stenting may reduce stroke risk when technically feasible 2

Important caveat: Most strokes in ICA dissection are embolic rather than hemodynamic in origin, as evidenced by the predominance of cortical and large subcortical infarcts rather than watershed patterns 5. This supports the rationale for antithrombotic therapy as first-line treatment.

Follow-Up and Monitoring

Imaging surveillance:

• Non-invasive imaging (duplex ultrasound, CTA, or MRA) at 1 month, 6 months, and annually to assess vessel patency and exclude new lesions 2, 6
• Serial imaging is critical because up to 38% of patients may develop abnormal findings requiring retreatment 4

Clinical monitoring:

• Assess for new neurological symptoms at each follow-up 2
• Screen for contralateral dissection, which occurs in approximately 2% of patients 6

Clinical Presentation Patterns to Recognize

Prodromal symptoms (occur before stroke in many cases):

• Unilateral headache or neck pain 1, 2
• Horner syndrome (ptosis, miosis, anhidrosis) on the affected side 1, 2
• After these warning symptoms, cerebral or retinal ischemia develops in 50-95% of cases 1, 2

Acute presentations:

• Transient ischemic attack (TIA) 6
• Ischemic stroke (accounts for 2% of all strokes, but 10-15% in patients under 45 years) 2
• Visual symptoms or amaurosis fugax 6

Critical Pitfalls to Avoid

• Do not delay treatment waiting for definitive imaging if clinical suspicion is high—early anticoagulation may prevent stroke in patients with prodromal symptoms 6
• Do not assume ultrasound alone is sufficient—it has a 95% sensitivity but may miss high cervical or vertebral dissections 2, 6
• Do not discontinue antithrombotic therapy prematurely—maintain for the full 3-6 months before transitioning to single antiplatelet therapy 1, 2
• Do not overlook the need for long-term follow-up imaging—vessel healing abnormalities may require retreatment in up to 17% of cases 4

Prognosis

• With appropriate antithrombotic therapy, recurrent stroke risk is very low 6
• Vessel recanalization occurs in many patients, with some showing complete resolution of dissection on follow-up imaging 7, 6
• Mortality from acute stroke in untreated or delayed diagnosis cases remains significant, emphasizing the importance of early recognition and treatment 6