What is the recommended management for cranial fibromuscular dysplasia?

Management of Cranial Fibromuscular Dysplasia

For symptomatic cranial FMD with prior stroke or TIA, initiate antiplatelet therapy (aspirin 81-325 mg daily), blood pressure control, and lifestyle modifications as first-line management; reserve carotid angioplasty with or without stenting only for patients with recurrent ischemic events despite optimal medical therapy. 1

Medical Management (First-Line for All Patients)

Antiplatelet Therapy

• Initiate antiplatelet therapy with aspirin (81-325 mg daily) for all patients with cranial FMD, regardless of symptom status 1, 2
• For symptomatic patients (prior stroke/TIA without other causes), antiplatelet therapy is a Class I recommendation 1
• For asymptomatic patients, platelet inhibitor therapy is reasonable to prevent thromboembolism, though optimal dosing is not established 1, 2
• Continue antiplatelet therapy long-term, especially when radiographic abnormalities persist 1

Blood Pressure Control

• Implement aggressive blood pressure control as part of comprehensive stroke prevention 1
• Target blood pressure management is essential given the vascular nature of FMD 3

Lifestyle Modifications

• Address modifiable risk factors including smoking cessation (approximately 50% of FMD patients have tobacco use history) 1, 4
• Implement standard stroke prevention lifestyle measures 1

Surveillance Imaging Strategy

Initial Monitoring

• Perform annual noninvasive imaging of carotid arteries initially to detect disease progression or severity changes 1, 2, 3
• Use duplex ultrasonography, CT angiography, or MR angiography for surveillance 3, 5
• Catheter angiography remains the gold standard for diagnosis but is reserved for cases where revascularization is being considered 5, 6

Long-Term Follow-Up

• Once stability is confirmed, imaging frequency can be reduced 1, 2, 3
• Continue surveillance indefinitely given the systemic nature of FMD 5, 6

Interventional Management (Reserved for Specific Indications)

When to Consider Revascularization

• Carotid angioplasty with or without stenting may be reasonable for patients with recurrent ischemic stroke despite optimal medical management 1
• This is a Class IIb recommendation (may be reasonable), indicating limited supporting evidence 1
• Consider intervention for symptomatic patients with retinal or hemispheric cerebral ischemic symptoms related to ipsilateral carotid FMD 1, 2

When NOT to Intervene

• Revascularization is NOT recommended for asymptomatic FMD regardless of stenosis severity (Class III: No Benefit) 1, 2
• This is a critical pitfall to avoid—severity of stenosis alone does not justify intervention in asymptomatic patients 1, 2

Special Considerations for FMD with Dissection

Dissection Without Intraluminal Thrombus

• Antiplatelet therapy is reasonable for patients with stroke/TIA attributable to dissection with FMD and no evidence of intraluminal thrombus (Class IIa) 1
• Avoid anticoagulation in intracranial dissections due to increased subarachnoid hemorrhage risk 1

Dissection With Persistent Symptoms

• For extracranial dissection with ongoing symptoms despite medical therapy, surgical procedures may be considered 1
• Options include proximal ligation, trapping procedures, or extracranial-intracranial bypass, though evidence is limited 1

Systemic Evaluation

Screen for Multivascular Involvement

• FMD is a systemic arterial disease requiring evaluation of other vascular territories 3, 5, 6
• Assess renal arteries (most commonly affected), vertebral arteries, and iliac arteries 3, 5, 6
• Screen for intracranial aneurysms, which can complicate cervicocranial FMD 5, 7

Aneurysm Management

• Aneurysm formation is a potential complication requiring specific attention 3, 5
• Ruptured intracranial aneurysms require either microvascular neurosurgical clipping or endovascular coiling 5

Clinical Outcomes and Prognosis

• Conservative management with antiplatelet therapy and risk factor modification results in low rates of recurrent cerebrovascular events 4
• In one cohort of 67 patients followed over time, only 1 patient experienced a cerebrovascular event (TIA), and 7 had progressive disease or additional symptoms 4
• Stenosis progression in FMD is typically slow 5, 7

Critical Pitfalls to Avoid

• Do not withhold antiplatelet therapy in asymptomatic patients—guidelines clearly support its use in carotid FMD 1, 2
• Do not perform revascularization based solely on stenosis severity in asymptomatic patients—this is explicitly not recommended 1, 2
• Do not use anticoagulation for intracranial dissections due to hemorrhage risk 1
• Do not fail to screen for multivascular involvement—FMD is a systemic disease 3, 5, 6