1Renal Unit The James Cook University Hospital Marton Road Middlesbrough 2Renal Unit The Freeman Hospital Newcastle upon Tyne, UK Email: john.main{at}stees.nhs.uk
Sir,
Van Ampting et al. [1] add more evidence to the literature regarding the common co-existence of atheromatous renal artery stenosis (ARAS) and renal failure. The fact that, in most cases, the ARAS was unilateral has only one explanationthe cause of nephron loss in these patients is not due to a stenosis of the renal artery.
Atherosclerotic hypertensive smokers are at risk of progressive renal failure and developing stenoses of any artery. This co-existence has been wrongly used to support the hypothesis that ARAS itself leads to progressive nephron loss. There is little evidence in favour of this, and lots against. Progressive renal failure is very unusual in the face of haemodynamically significant stenosis due to fibromuscular disease [2]. Individual kidney glomerular filtration rate studies in patients with chronic renal failure and unilateral ARAS show the renal impairment to be just as bad in the non-stenosed kidney [3]. Several studies have looked for and demonstrated ARAS in patients undergoing coronary angiography, for example, most recently, Agel et al. found that 28% of patients had clinically silent unilateral ARAS and 10% had bilateral ARAS [4]. In other words ARAS is often present without renal impairment. The failure to achieve significant benefits with regard to renal function despite successful intervention [5] is explained most easily if the ARAS is not causing the renal impairment.
This latest study confirms that, although it is easy to find ARAS in elderly end-stage renal failure patients, in most cases it is not the cause of their renal failure. There are undoubtedly a small group of clinical problems that are caused by ARAS that can be relieved by revascularization, but not enough evidence to suggest that progressive renal failure is one of them.
Conflict of interest statement. None declared.
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