- Non-atherosclerotic angiopathy of unknown cause that affects specific arteries
Incidence
- Young women (< 45yo)
Clinical
- If carotid artery affected → Sx of cerebrovascular disease
- TIAs = Most common manifestation
-
20% have a stroke by the time of presentation
- HTN ≈ 1/3 of pts due to renal artery involvement
Pathology
- Overgrowth of media (smooth muscle & fibrous tissue) in a segmental distribution → Concentric rings of Hyperplasia that project into the arterial lumen
- Very rarely a problem of intima or adventitia
- Involves straight central vessels
- Involves primarily:
- Middle 1/3 of extracranial ICA
- Middle/ distal 1/3 of Renal Artery
- External Iliacs
- Usually bilateral if cerebral & bilateral in 50% of renal cases
- In renal artery FMD - renal artery aneurysms frequently coexist
Investigaitons
- Radiology: String of beads in a long Internal Carotid Artery
- Angiography, MRA
Management
- Carotid:
- Due to high risk of stroke, lesion should be corrected by angioplasty with distal protection when pts develop Sx
- Surgery with dilation of carotid artery with graduated dilators or balloon dilation an alternative
- Renal:
- Balloon dilatation & stenting or surgery