fibromuscular dysplasia

Etiology

• idiopathic

Epidemiology

• women are affected more than men
• generally affects patients 15-30 years of age
  • most likely cause of hypertension in an asymptomatic young person with normal laboratory tests
• elderly patients with fibromuscular dysplasia may represent a more benign clinical phenotype

Pathology

• dysplastic disease affecting medium-size & small arteries
• disease can affect any layer of the arterial wall, medial fibroplasia is most common
• 60-70% have renal vascular involvement
• cerebrovascular involvement occurs in 30% of cases
• stenotic lesions (renal artery stenosis) may limit or occlude blood flow & predispose to aneurysm formation or dissection
• not a result of atherosclerosis or inflammation

Clinical manifestations

• most common presentation is hypertension

Laboratory

• plasma renin activity elevated with renal vascular involvement
• other laboratory tests normal

Radiology

• duplex renal ultrasound
  • may show asymmetric kidney size
  • doppler may show renal artery stenosis
• renal artery CT angiography: (gold standard)
  • 'string of beads' appearance
  • represents alternating stenotic & aneurysmal regions of arteries
• computed tomographic angiography
  • sensitivity suboptimal for detecting distal renal artery stenosis, a common location for fibromuscular dysplasia

Management

• antiplatelet therapy for asymptomatic individuals
• percutaneous transluminal angioplasty for symptomatic patients
  • 2/3 of patients cured by angioplasty alone
• surgery when angioplasty fails or when aneurysm or dissection is present

More general terms

• dysplasia
• arterial disease

Additional terms

• percutaneous transluminal coronary angioplasty (PTCA)
• renal artery stenosis (RAS)