Arterial Fibrodysplasia

1. Arterial Fibrodysplasia

2. Arterial fibrodysplasia • Heterogeneous group of nonatherosclerotic, noninflammatory occlusive and aneurysmal diseases • Classified by layer affected – intima, media, adventitia • Most often renals and carotids, but described everywhere in the body

3. Arterial fibrodysplasia

4. Arterial fibrodysplasia • First described 1938 by Leadbetter • Second leading cause of surgically correctable of hypertension • Incidence < 0.5%

5. Arterial fibrodysplasia Pathogenesis • Unknown • Genetic – more common among first degree relatives with FMD and certain alleles of ACE • Hormonal influences on smooth muscle • Mechanical stress

6. Arterial fibrodysplasia DDx • Atherosclerosis – usually occurs at origin or proximal part of vessels in older patients with usual risk factors • Vasculitis – may look like FMD on imaging, but will have biochemical (or pathologic) evidence of inflammation

7. Renal artery dysplasia • Medial fibrodysplasia -- the big one (85%) • 90% female, usually 4th decade • Rare among African Americans • Morphology ranges from focal stenosis to series of stenoses with intervening aneurysmal outpouchings (“string of beads”) • Affects distal main renal artery, extending into 1st order segmanetal branches 25%

8. Renal artery dysplasia • Progression (new lesion, worse stenosis, larger aneurysm, HTN, loss of renal parenchyma) of disease occurs in 12-66% of patients, usually premenopausal women • In one series, 18% developed complete occlusion

9. Renal artery dysplasia

10. Renal artery dysplasia

11. Renal artery dysplasia

12. Renal artery dysplasia

13. Renal artery dysplasia Treatment • Medical treatment of HTN • Revascularization for patients who failed medical therapy, are noncompliant, or with loss of renal volume due to ischemic nephropathy • Surgery – 70-90% success rate (worse with longstanding HTN, concomitant atherosclerosis, complex branch vessel repair)

14. Renal artery dysplasia Treatment • PTA – mainstay of treatment • Lower morbidity, still allows for surgery later • Equally effective in main renal artery and branch stenoses • Stents usually reserved if results suboptimal after balloon or if dissection • Complications in 14% (access related problems, dissection, perforation, renal segment infarction) • Restenosis up to 27% after 2 years

15. Renal artery dysplasia Treatment • Follow-up after revascularization • Duplex imaging after procedure, 6 mo, 12 mo, then yearly to detect disease progression, restenosis, or loss of renal volume

16. Renal artery dysplasia Treatment

17. Cerebrovascular artery dysplasia • 0.4% of patients undergoing cerebral arteriogram • May cause HA, tinnutus, syncope, TIA, stroke • Symptoms may be due to stenosis, embolism or aneurysm rupture • In last 10 years, PTA has supplanted surgery as preferred treatment

18. Other vascular beds • External iliac arteries next most commonly affected • May present with claudication, critical limb ischemia, or peripheral embolism • In mesenteric arteries, may lead to intestinal angina or acute mesenteric ischemia (rarely)

19. Final points • Nonatherosclerotic, noninflammatory disease affecting medium sized arteries (most often renals) • Most commonly women 15-50 years old • Pathogenesis poorly understood • PTA treatment of choice • Stents usually not needed