What is the treatment for bilateral renal artery stenosis?

Treatment of Bilateral Renal Artery Stenosis

For patients with bilateral renal artery stenosis, initial medical therapy should be attempted, with revascularization reserved for those who fail medical management, develop progressive renal dysfunction, or experience flash pulmonary edema. 1

Diagnostic Approach

• Diagnosis depends on clinical suspicion and arterial imaging for patients with unexplained progressive hypertension or renal dysfunction 1
• Duplex ultrasound is recommended as first-line imaging to identify increased peak systolic velocity in renal arteries 1
• Confirmation with CT angiography or MR angiography is often needed before invasive studies 1

Medical Management (First-Line Therapy)

Pharmacological Options:

• Calcium channel blockers, beta-blockers, and diuretics are recommended first-line treatments for hypertension associated with bilateral renal artery stenosis 1
• ACE inhibitors or ARBs may be considered in bilateral renal artery stenosis but require close monitoring due to risk of acute kidney injury 1, 2, 3

Monitoring During Medical Therapy:

• Monitor serum creatinine closely when initiating ACE inhibitors/ARBs in bilateral disease 2, 3
• A rise in serum creatinine >30% may indicate need for revascularization 1
• Increases in blood urea nitrogen and serum creatinine are usually reversible upon discontinuation of ACE inhibitors/ARBs 2

Indications for Revascularization

Revascularization should be considered in patients with bilateral renal artery stenosis who have:

• Failed antihypertensive drug therapy 1
• Progressive loss of renal function 1
• Episodes of flash pulmonary edema 1
• Acute oligo-anuric renal failure with kidney ischemia 1

Revascularization Options

Endovascular Procedures:

• Endovascular stenting is the preferred revascularization method for atherosclerotic bilateral renal artery stenosis 1
• Balloon angioplasty with bailout stenting is preferred for fibromuscular dysplasia 1
• Restenosis may develop in 15-24% of treated patients 1

Surgical Revascularization:

• Reserved for patients with complex anatomy, associated aortic disease, or after failed endovascular therapy 1
• Higher complication rates compared to endovascular approaches 1

Special Considerations

Atherosclerotic vs. Fibromuscular Dysplasia:

• Atherosclerosis accounts for approximately 90% of bilateral renal artery stenosis cases, especially in older patients 4
• Fibromuscular dysplasia (10% of cases) is more common in younger patients, especially women 4
• Treatment approach differs: stenting for atherosclerotic disease vs. angioplasty without stenting for FMD 1

Post-Revascularization Management:

• Most patients will still require antihypertensive medications after revascularization 1
• ACE inhibitors/ARBs may be safely restarted after successful revascularization 5
• Continue to monitor for restenosis, which may not always be associated with worsening hypertension or kidney function 1

Outcomes and Prognosis

• Observational studies show improved BP control and mortality after successful revascularization 1
• Post-hoc analysis of the CORAL trial suggests mortality benefit of revascularization in patients without proteinuria 1
• The most reliable predictor for effective BP reduction after revascularization is a short duration of pressure elevation 1

Pitfalls and Caveats

• Routine revascularization is not recommended for all patients with atherosclerotic renal artery stenosis 1
• Revascularization procedures carry significant risks including bleeding, athero-embolic events, and procedure-related complications 6
• ACE inhibitors/ARBs can cause acute kidney injury in bilateral renal artery stenosis and require careful monitoring 2, 3
• Randomized trials have shown modest benefits of angioplasty over medical therapy alone, primarily in bilateral disease 6