Prevalence of Renal Artery Stenosis at the Time of Cardiac Catheterization
Complications of Renal Stent Placement
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Renal artery stenosis (RAS) is common among patients with atherosclerosis, and is found in 20-30% of individuals who undergo diagnostic cardiac catheterization. Renal artery duplex ultrasonography is the diagnostic procedure of choice for screening outpatients for RAS. Percutaneous renal artery stent placement is the preferred method of revascularization for hemodynamically significant RAS, and is favored over balloon angioplasty alone. Stent placement carries a class I recommendation for atherosclerotic RAS according to ACC and AHA guidelines. Discordance exists between the very high (>95%) procedural success rate and the moderate (60-70%) clinical response rate after renal stent placement, which is likely to be a result of poor selection of patients, inadequate angiographic assessment of lesion severity, and the presence of renal parencyhmal disease. Physiologic lesion assessment using translesional pressure gradients, and measurements of biomarkers (e.g. brain natriuretic peptide), or both, could enhance the selection of patients and improve clinical response rates. Longterm patency rates for renal stenting are excellent, with 5-year secondary patency rates greater than 90%. This Review will outline the clinical problem of atherosclerotic RAS and its diagnosis, and will critically assess treatment options and strategies to improve patients' outcomes.
Patients with atherosclerotic coronary artery disease or peripheral arterial disease, associated with uncontrolled hypertension or renal insufficiency, are at increased risk for renal artery stenosis (RAS).[1] When selecting patients for renal artery stenting, both functional and anatomical data should be considered to optimize the benefit of revascularization for each individual. Well-accepted indications for renal artery revascularization are outlined in Box 1 . Primary stent placement (the practice of deploying a stent regardless of the result of balloon angioplasty as opposed to provisional stent placement, where stenting is performed only if the balloon angioplasty result is poor), has largely replaced surgical therapy in patients with suitable anatomy who do not respond to medical therapy.[2] In this Review, we examine the management of RAS in the context of diagnostic imaging, patient selection to improve the treatment response rate, and procedural safety.