Arterial Fibrodysplasia

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

Arterial fibrodysplasia

Arterial fibrodysplasia

First described 1938 by Leadbetter Second leading cause of surgically correctable

of hypertension Incidence < 0.5%

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

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

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%

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

Renal artery dysplasia

Renal artery dysplasia

Renal artery dysplasia

Renal artery dysplasia

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)

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

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

Renal artery dysplasia Treatment

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

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)

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