What are the management and treatment options for symptoms related to the interior medullary artery in patients with Fibromuscular Dysplasia (FMD)?

Management of Interior Medullary Artery Symptoms in FMD

I need to clarify that the question appears to reference the "interior medullary artery," but the provided evidence exclusively addresses fibromuscular dysplasia (FMD) affecting the carotid, vertebral, and renal arteries—not specifically medullary arteries. Assuming you're asking about intracranial/vertebral artery FMD symptoms (which supply the medulla), I'll address management based on the strongest available guideline evidence for cerebrovascular FMD.

Symptomatic Disease Management

For patients with neurological ischemic symptoms (stroke, TIA, or vertebrobasilar symptoms) from FMD affecting cerebrovascular arteries, initiate antiplatelet therapy immediately and consider angioplasty with or without stenting for symptomatic disease. 1

Initial Medical Management

• Start antiplatelet therapy in ALL patients with cerebrovascular FMD, regardless of symptom status, to prevent thromboembolism 1

  • Aspirin 81-325 mg daily is the standard regimen 1
  • Alternative options include clopidogrel 75 mg daily or aspirin plus extended-release dipyridamole (25/200 mg twice daily) 1
  • The optimal drug and dosing regimen have not been definitively established, but aspirin remains first-line 1, 2

• Obtain contrast-enhanced imaging (CTA, MRA, or catheter angiography) to confirm diagnosis and assess extent of disease 1

Revascularization Decisions

Carotid or vertebral angioplasty with or without stenting is reasonable for patients with retinal or hemispheric cerebral ischemic symptoms related to FMD of the ipsilateral artery (Class IIa recommendation) 1

• This applies to symptomatic patients with stroke, TIA, or ongoing ischemic symptoms 1, 3
• Comparative data between angioplasty alone versus stenting are not available 1

Do NOT revascularize asymptomatic FMD regardless of stenosis severity (Class III: No Benefit) 1, 3, 2

Special Consideration: Arterial Dissection

If symptoms are due to carotid or vertebral artery dissection (a recognized complication of FMD presenting with headache, Horner syndrome, or stroke) 4, 5:

• Initiate antithrombotic therapy for 3-6 months (Class IIa) 1

  • Either anticoagulation: IV heparin (PTT 1.5-2.0× control) followed by warfarin (INR 2.0-3.0), OR low-molecular-weight heparin followed by warfarin 1
  • OR antiplatelet therapy: aspirin 81-325 mg daily or clopidogrel 75 mg daily 1

• After 3-6 months, transition to long-term antiplatelet therapy 1

• Consider angioplasty and stenting only if ischemic symptoms persist despite antithrombotic therapy (Class IIb) 1

Surveillance Protocol

• Perform annual noninvasive imaging (duplex ultrasound, CTA, or MRA) initially to detect disease progression 1, 4, 3, 2
• Reduce imaging frequency once stability is confirmed over 2-3 years 4, 3, 2

Clinical Manifestations to Recognize

FMD affecting vertebrobasilar circulation can present with 1, 4, 2:

• Stroke or TIA from reduced blood flow or thromboembolism 4, 2
• Spontaneous arterial dissection 4, 5
• Horner syndrome 4, 2, 5
• Cranial nerve palsies 4, 2
• Subarachnoid hemorrhage from aneurysmal rupture 4, 2, 5

Common Pitfalls to Avoid

• Do not withhold antiplatelet therapy in asymptomatic patients—guidelines clearly support its use even without symptoms 3, 2
• Do not revascularize asymptomatic disease—this exposes patients to procedural risk without proven benefit 1, 3, 2
• Do not assume FMD is limited to one vascular bed—it is a systemic arterial disease requiring comprehensive imaging from head to pelvis at diagnosis 4, 5, 6
• Consider dissection in any FMD patient with acute neurological symptoms—this changes management to antithrombotic therapy rather than immediate revascularization 1