Does Renal Artery Stenting Preserve Kidney Function?
Although atherosclerotic renal artery lesions tend to progress with time, relatively few arteries go to complete occlusion within a 5-year period.12 In the absence of complete occlusion, there is little or no correlation between the degree of anatomic stenosis and glomerular filtration rate. In 1 study in patients with unilateral RAS and an apparently normal contralateral kidney, glomerular filtration rate ranged from normal to nearly zero when, at most, a 50% reduction might be expected.13 Similarly, nuclear studies in patients with unilateral RAS reveal that glomerular filtration rate in the nonstenotic kidney often is the same as or even lower than that in the kidney distal to a stenosis.14 The lack of correlation between the severity of renal arterial disease and kidney function probably relates to the presence of ischemic damage in the poststenotic kidney and hypertensive injury in the nonstenotic kidney. Thus, in many patients with RAS, intrinsic kidney damage rather than the vas
