What is the management approach for fibromuscular dysplasia (FMD)?

Management of Fibromuscular Dysplasia

All patients with fibromuscular dysplasia should receive antiplatelet therapy and undergo annual noninvasive imaging surveillance initially, with revascularization reserved exclusively for those with symptomatic disease causing retinal or hemispheric ischemia, refractory hypertension, or progressive renal dysfunction. 1

Initial Diagnostic Workup

Imaging Strategy:

• Begin with duplex ultrasonography as the initial screening test 2
• Proceed to CT angiography or MR angiography for comprehensive vascular bed assessment 2
• Reserve catheter angiography (the gold standard) for cases where noninvasive tests are inconclusive or when you plan to proceed with revascularization during the same procedure 2, 3
• Do not order captopril renal scintigraphy, selective renal vein renin measurements, or plasma renin activity—these are not recommended screening tests 2

Systemic Evaluation:

• FMD is a systemic arterial disease, not a localized condition 2, 3
• Evaluate all major vascular territories, particularly carotid, vertebral, renal, and iliac arteries, even if only one site is symptomatic 2, 4
• Screen for aneurysms, which are a recognized complication 2

Medical Management (All Patients)

Antiplatelet Therapy:

• Administer platelet-inhibitor medication to all patients with FMD to prevent thromboembolism, though the optimal drug and dosing regimen remain undefined 1

Blood Pressure Control:

• All patients require appropriate antihypertensive therapy 2
• RAS blockers (ACE inhibitors or ARBs) are the drugs of choice when percutaneous intervention is not feasible 2
• Critical caveat: Monitor renal function carefully when using RAS blockers, as these patients may have bilateral disease 2

Surveillance Imaging:

• Perform annual noninvasive imaging of affected arteries initially to detect progression 1
• Once stability is confirmed over 2-3 years, imaging frequency can be reduced 1

Revascularization Decisions

Renal Artery FMD:

Indications for intervention:

• Refractory hypertension despite optimal medical therapy 1, 2
• Progressive renal dysfunction 1
• Intractable heart failure 1

Technique selection:

• Percutaneous transluminal renal angioplasty (PTRA) without stenting is first-line for symptomatic renal FMD 2, 5, 6
• Use stenting only for dissection or balloon angioplasty failure 2
• Reserve open surgical revascularization for complex aneurysms, lesions involving arterial bifurcations/branches, or failed endovascular therapy 2

Important distinction: Multifocal FMD (the classic "string-of-beads" appearance) can often be managed conservatively with medication alone, particularly in older patients with less severe hypertension 7. The natural history is relatively benign with progression occurring in only a minority 6.

Carotid/Vertebral Artery FMD:

Indications for intervention:

• Retinal or hemispheric cerebral ischemic symptoms (TIA or stroke) related to FMD of the ipsilateral carotid artery 1
• Symptomatic dissection 3, 5

Technique selection:

• Carotid angioplasty with or without stenting is reasonable, though comparative data are lacking 1

Absolute contraindication to revascularization:

• Do not revascularize asymptomatic FMD of any artery, regardless of stenosis severity 1
• This is a Class III (No Benefit) recommendation—revascularization provides no proven benefit and exposes patients to procedural risk 1

Common Pitfalls to Avoid

• Do not assume FMD is localized: Always evaluate multiple vascular beds, as this is a systemic disease affecting 4% of adult women 5, 4
• Do not rush to revascularization: The natural history is relatively benign, and medical management achieves blood pressure control below 140/90 mmHg in two-thirds of patients across all treatment groups 7
• Do not stent routinely: Stenting in renal FMD should be reserved for complications, not used as primary therapy 2
• Do not ignore the younger patient with hypertension: Consider FMD in anyone ≤35 years with new-onset hypertension or any young person with a cervical bruit 5

Special Populations

Focal vs. Multifocal Disease:

• Focal FMD (tubular stenosis) more often requires revascularization and occurs more frequently in men diagnosed at younger ages with higher blood pressure 7
• Multifocal FMD (string-of-beads, >80% of cases) can be managed conservatively in approximately 60% of cases with similar blood pressure outcomes to revascularization 7

Aneurysm Management:

• Treat aneurysms with covered stents or open surgical repair 5
• For ruptured intracerebral aneurysms, options include microvascular neurosurgical clipping or endovascular coiling 3