Renal Artery Stenosis

Question 1

Define renal artery stenosis.

Answer 1

Renal artery stenosis (RAS) is a narrowing of the renal artery lumen. It is considered angiographically significant if more than a 50% reduction in vessel diameter is present.

Question 2

Explain the aetiology/risk factors of renal artery stenosis.

Answer 2

Dyslipidaemia
Smoking
Diabetes

Question 3

Summarise the epidemiology of renal artery stenosis.

Answer 3

RAS has a prevalence of 0.2% to 5% in all hypertensive patients. Atherosclerotic RAS accounts for 90% of all RAS. Prevalence is as high as 25% in patients with CAD undergoing cardiac catheterisation. Two percent of end-stage renal disease (ESRD) is due to ischaemic nephropathy.

Question 4

Recognise the presenting symptoms of renal artery stenosis. Recognise the signs of renal artery stenosis on physical examination.

Answer 4

Onset of hypertension age >55 years
History of accelerated, malignant, or resistant hypertension
History of unexplained kidney dysfunction
History of multi-vessel coronary artery disease
History of other peripheral vascular disease
Abdominal bruit
Sudden or unexplained recurrent pulmonary oedema

Question 5

Identify appropriate investigations for renal artery stenosis and interpret the results.

Answer 5

Serum creatinine
Serum potassium
Urinalysis and sediment evaluation
Aldosterone-to-renin ratio
Duplex ultrasound
CT angiography