Renal aery stenosis may occur In all of the following except -

Renal aery stenosis classically presents as hypeension if it affects a single kidney or as renal failure if it is bilateral. The hypeension is driven by activation of the renin-angiotensin system in response to renal ischaemia. In atherosclerotic renal aery disease, there is usually evidence of vascular disease elsewhere, paicularlyin the legs. Repeated episodes of acute pulmonary oedema associated with severe hypeension, occurring without other obvious cause (e.g. myocardial infarction, dysrhythmia, anaemia, thyrotoxicosis) in patients with normal or only mildly impaired renal and cardiac function, can occur in renal aery stenosis. This presentation is characteristic of bilateral renovascular disease because in unilateral disease salt and water retention are paly corrected by increased 'pressure natriuresis' in the normal kidney.in younger patients (< 50 years), fibromuscular dysplasia is a more likely cause of renal aery stenosis. This is an uncommon congenital disorder of unknown cause affecting the media ('medial fibroplasia'), which narrows the aery but rarely leads to total occlusion. It may be associated with disease in other aeries; for example, those who have carotid aery dissections are more likely to have this appearance in their renal aeries. It most commonly presents with hypeension in patients aged 15-30 years, and in women more frequently than men. Irregular narrowing ('beading') affects the distal renal aery, sometimes extending into intrarenal branches. ref:Harrison&;s principles of internal medicine,ed 18,pg no 2455