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Renal artery stenosis and fibromuscular dysplasia
Atherosclerotic renal artery stenosis (in an older patient, at the ostium) is treated medically in most cases, because CORAL and ASTRAL showed no benefit from stenting; fibromuscular dysplasia (FMD) — in a young woman, in the mid artery, with a "string of beads" appearance — responds well to plain balloon angioplasty, no stent needed; revascularisation in atherosclerosis is kept for special situations such as recurrent "flash" pulmonary oedema.
Why it matters in the exam
The exam asks to recognise when to suspect renovascular hypertension and what to do. Clues: hypertension starting before age 30 or after age 55, resistant or suddenly worsening hypertension, an abdominal bruit, kidney size asymmetry of more than 1.5 cm, hypokalaemia (from secondary aldosteronism), and a rise in creatinine of more than 30% after starting ACE inhibitors or ARB — suggesting bilateral stenosis or stenosis in a solitary kidney. The first test is duplex (peak velocity above 180–200 cm per second, or a renal-to-aortic velocity ratio above 3.5), followed by CTA or MRA.
In atherosclerotic stenosis the treatment is best medical therapy: blood pressure control (including ACE inhibitors or ARB with monitoring of kidney function), statin, antiplatelet therapy and smoking cessation. The ASTRAL (2009) and CORAL (2014) trials did not show that stenting improves blood pressure, kidney function or cardiac events. Revascularisation is considered for recurrent unexplained pulmonary oedema ("flash pulmonary oedema"), rapidly worsening kidney failure with bilateral stenosis or a solitary kidney, and truly resistant hypertension. In FMD — mainly a woman aged 15–50 — the common type is the multifocal type with a "string of beads" in the mid and distal artery; the treatment for hypertension is balloon angioplasty without a stent, with a good chance of improvement, especially in the young. FMD is a systemic disease, so imaging of all the arteries (CTA from head to pelvis) is done to look for aneurysms and dissections, including in the neck and brain arteries.
In a patient with FMD and cervical artery dissection or a brain aneurysm, the renal finding is only part of the picture, so management includes multisystem follow-up.
Key points
- Atherosclerotic — ostial, medical treatment.
- CORAL and ASTRAL — no benefit from stenting.
- Recurrent pulmonary oedema — consider a stent.
- FMD — young woman, "string of beads", balloon.
- FMD — imaging of all arteries.
Summary table
| Feature | Atherosclerotic stenosis | FMD |
|---|---|---|
| Typical patient | Older, smoker, other vascular disease | Woman aged 15–50 |
| Location | Ostium, proximal segment | Mid and distal artery, "string of beads" |
| Treatment | Best medical therapy; stent in special situations | Balloon angioplasty without a stent |
| Trials or further work-up | CORAL and ASTRAL: no benefit from stenting | Imaging of all arteries |
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Sources
- ESC Guidelines for the management of peripheral arterial and aortic diseases, 2024 — Renal artery disease
- First International Consensus on the diagnosis and management of fibromuscular dysplasia, 2019 — Diagnosis and treatment
- Cooper et al., CORAL, N Engl J Med, 2014 — Stenting and medical therapy for atherosclerotic renal-artery stenosis
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.