Dilemmas in the management of renal artery stenosis.

Atherosclerotic renovascular disease (ARVD) accounts for >90% of renal artery stenosis (RAS) in Western populations; the remainder are due to fibromuscular disease (FMD). The epidemiology is quite different in the Indian subcontinent and the Far East where Takayasu's arteritis may be responsible for up to 60% of RAS cases. ARVD is very commonly associated with hypertension and renal dysfunction; it is a disease of ageing and is frequently observed in association with other vascular diseases. There is increasing evidence that in patients with ARVD and chronic renal dysfunction the aetiology of the latter is more often due to long-standing intra-renal vascular disease and parenchymal injury than to reversible ischaemia. This is reflected in the variability in renal functional outcome following revascularization, with an improvement in renal function being observed in only a minority of patients; the majority show no apparent change or even a decline in renal function. A major current challenge concerns the identification of patients who are likely to benefit from renal revascularization procedures, but technological advances in imaging offer potential in aiding this selection. Large-scale randomized controlled trials are required to determine the overall effects of renal artery intervention and, more specifically, to help identify which subgroups of patients will benefit from revascularization.