What is the management approach for fibrocystic dysplasia?

Management of Fibromuscular Dysplasia

Percutaneous transluminal renal angioplasty (PTRA) without stenting is the first-line revascularization technique for symptomatic renal fibromuscular dysplasia (FMD), which can restore renal perfusion pressure and effectively lower blood pressure. 1

Diagnostic Approach

• Duplex ultrasonography is recommended as an initial screening test for FMD (Class I recommendation) 1
• Computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) are appropriate screening tests when FMD is suspected 1
• Catheter angiography remains the gold standard for diagnosing FMD and should be performed when clinical suspicion is high and noninvasive tests are inconclusive 1
• FMD lesions are typically truncal or distal in the renal artery, which distinguishes them from atherosclerotic lesions that are more often proximal or ostial 2

Treatment Algorithm

Step 1: Initial Medical Management

• All patients with FMD should receive appropriate medical therapy to reduce blood pressure as first-line treatment 1
• RAS blockers (ACEIs/ARBs) are the drugs of choice when percutaneous intervention is not feasible, but require careful monitoring of renal function 1
• Blood pressure control is essential to prevent complications in other vascular beds, as FMD is now recognized as a systemic disease 1, 3

Step 2: Indications for Revascularization

Consider invasive treatment when:

• Hypertension cannot be adequately controlled with antihypertensive medications 2
• Patient has impaired renal function or ischemic nephropathy 2
• Recurrent flash pulmonary edema or resistant hypertension is present 4

Step 3: Revascularization Approach

• PTRA without stenting is the treatment of choice for symptomatic renal FMD (Class IIa recommendation) 1, 4
• Pressure gradients are normally completely abolished with PTRA, and there is typically no indication for stent placement 2
• Stenting should be considered only for management of dissection or balloon angioplasty failure 1

Step 4: Surgical Management

Surgical revascularization is indicated in cases of:

• PTRA complications (thrombosis, perforation, progressive dissection) 2
• Repeated PTRA failure or restenosis 2
• Complex aneurysms or lesions involving arterial bifurcation or branches 1

Special Considerations

• FMD is significantly more prevalent in females than males (>4:1 ratio), accounting for up to 10% of cases of renovascular hypertension 2
• FMD patients are typically younger and have fewer risk factors for atherosclerosis compared to those with atherosclerotic renal artery stenosis 2
• Evaluation of other arterial territories, particularly carotid and vertebral arteries, is necessary as FMD can affect multiple vascular beds 1, 3
• Aneurysm formation is a potential complication that requires monitoring 1
• Centralization of management in specialized centers is recommended for optimal outcomes 2

Follow-up Recommendations

• Regular monitoring of blood pressure and renal function is essential after revascularization 3
• Long-term follow-up imaging may be necessary to detect restenosis or development of aneurysms 1
• Patients should be monitored for potential involvement of other vascular beds over time 1, 3

Pitfalls and Caveats

• Do not confuse FMD with atherosclerotic renal artery stenosis, as the treatment approaches differ 2
• Avoid stenting in FMD unless specifically indicated, as angioplasty alone is usually sufficient 1, 2
• Remember that FMD is a systemic disease that can affect multiple vascular territories beyond the renal arteries 1, 3
• Careful monitoring of renal function is necessary when using RAS blockers in patients with bilateral renal artery stenosis or stenosis in a solitary functioning kidney 4, 1