American Urological Association - Renovascular Hypertension: Fibromuscular Dysplasia
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Renovascular Hypertension: Fibromuscular Dysplasia

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  • Defined as fibrous and fibromuscular non-atherosclerotic or non-inflammatory stenosis of renal artery.
  • Found in ~30% of patients with renovascular hypertension.
  • Incidence 4/1000 for symptomatic renal FMD, medial fibroplasia 60-85%, perimedial fibroplasia 10-20% and intimal 1-5%.
  • Occurs at an earlier age than atherosclerosis (3rd to 4th decade) and is more common in women (medial form) (vs. older male in AS).
  • Intimal form common in male.
  • The pathogenesis remains unclear: arterial dysplasias are not confined to the kidney (cerebral, carotid, etc. can be affected)
  • 60-90% involve renal arteries; 50% bilateral, involves distal 2/3.
  • May also involve other vessel carotid arteries (26%) and mesenteric arteries (9%).
  • Mostly circumferential thickening; intimal can be eccentric.
  • Subclassified according to the part of the arterial wall is involved:
    • Intimal fibroplasia (primary and secondary)
    • Medial hyperplasia:
    • Medial fibroplasia with aneurysms
    • Perimedial fibroplasia
    • Periarterial fibroplasia
  • Cure rate for all types is 70% following surgery