renal artery stenosis

Question 1

definition

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.[1] Ischaemic nephropathy is a chronic reduction in glomerular filtration rate that occurs from a narrowing in the renal artery. Renovascular hypertension is hypertension mediated by high levels of renin and angiotensin II, produced by an underperfused kidney supplied by a stenosed renal artery.

Typically due to atherosclerotic disease or fibromuscular dysplasia.

Often presents with accelerated or difficult-to-control hypertension.

Worsening kidney function, especially after initiating renin-angiotensin blockade, and recurrent flash pulmonary oedema are common features.

Presence of renal artery narrowing does not necessarily indicate clinical consequences. Renal artery stenosis, renovascular hypertension, and ischaemic nephropathy are various manifestations of this process.

Definitive diagnosis is with imaging.

Question 2

signs and symptoms

Answer 2

• history of accelerated, resistant or malignant hypertension
• unexplained kidney dysfunction
• history of multi-vessel coronary artery disease
• history of other peripheral vascular disease
• abdominal bruit
• sudden or unexplained recurrent pulmonary oedema
• history of acute kidney injury after administration of ARB or ACEi

Question 3

risk factors

Answer 3

• hypertension, onset of hypertension after 55
• dyslipidaemia
• smoking
• diabetes

Question 4

investigations

Answer 4

1st investigations:

• serum creatinine (to calculate GFR)
• serum potassium
• urinalysis and sediment evaluation
• aldosterone to renin ratio

test for diagnosis:
angiogram