Atherosclerotic Renal Artery Stenosis Where's Waldo?

We have all treated patients who dramatically improve declining renal function, previously uncontrollable hypertension, or episodic flash pulmonary edema after stenting a severe atherosclerotic renal artery lesion(s). Experience with these success stories has proven that atherosclerotic renal artery stenosis (RAS) in some patients (the Waldos in the crowd of patients with atherosclerotic RAS) can impair renal perfusion and activate the renin-angiotensin system to amplify hypertension. However successful stenting of atherosclerotic renal artery lesions rarely cures hypertension and improves blood pressure in only 50% to 70% of patients (1), whereas renal function is improved in only 25% of those with impaired glomerular filtration at baseline (2). In fact, renal function deteriorates in 10% to 20% of patients after "successful" stenting. Many different issues contribute to clinical outcome after renal artery stenting, and more reliable predictors for selecting patients who are likely to clinically benefit from stenting atherosclerotic RAS are needed. We should require more than simply visualizing a stenosis before stenting is performed (3).