Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 22-12: Renal Artery Stenosis + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Produced by atherosclerotic occlusive disease (most patients) or fibromuscular dysplasia Hypertension Acute kidney injury with initiation of angiotensin-converting enzyme (ACE) inhibitor therapy if stenosis is bilateral +++ General Considerations ++ Atherosclerotic ischemic renal disease Accounts for most cases of renal artery stenosis Occurs most commonly in persons older than age 45 who have a history of atherosclerotic disease elsewhere Other risk factors include Chronic kidney disease Diabetes mellitus Tobacco use Hypertension Fibromuscular dysplasia is a less common cause +++ Demographics ++ Approximately 5% of Americans with hypertension suffer from renal artery stenosis + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Refractory hypertension New-onset hypertension in older patient Pulmonary edema with poorly controlled blood pressure Acute kidney injury upon starting an ACE inhibitor Abdominal bruit on affected side +++ Differential Diagnosis ++ Hypertensive nephrosclerosis Primary hyperaldosteronism Cushing syndrome Coarctation of the aorta + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests ++ Elevated blood urea nitrogen and serum creatinine Hypokalemia May be found in patients with bilateral renal artery stenosis Reflects activation of the renin-angiotensin-aldosterone system in response to reduced blood flow (a "prerenal" state) +++ Imaging Studies ++ Abdominal ultrasound shows asymmetric kidney size Initial screening tests: Doppler ultrasonography, CT angiography, and magnetic resonance angiography (MRA) Doppler ultrasonography Highly sensitive and specific (85% and 92%, respectively, in a meta-analysis of 88 studies) and relatively inexpensive Poor choice for patients who are obese, unable to lie supine, or have interfering bowel gas patterns CT angiography A noninvasive procedure Consists of intravenous digital subtraction angiography with arteriography Uses a spiral (helical) CT scan with intravenous contrast injection Sensitivity ranges from 77% to 98% and specificity from 90% to 94% MRA Excellent but expensive Sensitivity is 77% to 100% and specificity ranges from 71% to 96% Turbulent blood flow can cause false-positive results The imaging agent gadolinium has been associated with nephrogenic systemic fibrosis, which occurs Primarily in patients with GFR < 15 mL/min/1.73 m2 Rarely in patients with GFR of 15–30 mL/min/1.73 m2 or greater In patients with acute kidney injury In kidney transplant patients Renal angiography Gold standard for diagnosis; performed after initial imaging test result is abnormal Fibromuscular dysplasia has characteristic "beads-on-a-string" appearance CO2 subtraction angiography used when risk of dye nephropathy exists (eg, diabetic patients with kidney injury) Risk of atheroembolic phenomena after angiography ranges from 5% to 10% + Treatment Download Section PDF Listen +++ +++ Medications ++ Pharmacologic antihypertensive agents that avoid ACE inhibitors and ACE receptor blockers +++ Surgery ++ Surgical bypass (revision) is an option for atherosclerotic ischemic renal disease +++ Therapeutic Procedures ++ Angioplasty for atherosclerotic ischemic renal disease Might reduce number of antihypertensive medications Equally as effective as, and safer than, surgical revision Stenting Produces significantly better results than angioplasty However, blood pressure is equally improved, and serum creatinines are similar at 6 months of observation Percutaneous transluminal angioplasty can be curative for fibromuscular dysplasia + Outcome Download Section PDF Listen +++ +++ Follow-Up ++ Monitor blood pressure, kidney function, serum lipids +++ Complications ++ Resistant hypertension Chronic kidney disease +++ When to Refer ++ Inability to control hypertension Kidney injury +++ When to Admit ++ Malignant hypertension + References Download Section PDF Listen +++ + +Cooper CJ et al; CORAL Investigators. Stenting and medical therapy for atherosclerotic renal-artery stenosis. N Engl J Med. 2014 Jan 2;370(1):13–22. [PubMed: 24245566] + +O'Connor SC et al. Recent developments in the understanding and management of fibromuscular dysplasia. J Am Heart Assoc. 2014 Dec;3(6):e001259. [PubMed: 25527625] + +Raman G et al. Comparative effectiveness of management strategies for renal artery stenosis: an updated systematic review. Ann Intern Med. 2016 Nov 1;165(9):635–49. [PubMed: 27536808]