The Effect of Endovascular Treatment of Renal Artery Stenoses on Coexistent Aneurysms Associated with Fibromuscular Dysplasia

 

Clinical question

Is renal artery stenting safe and effective for patients with coexisting renal artery aneurysms secondary to fibromuscular dysplasia?

Take away point

Renal artery stenting is safe and effective in the setting of FMD related renal artery aneurysms, and can lead to overall regression in aneurysm size.

Reference

Chen Y, Dong H, Zou Y, Li H, Che W, Xiong H, Jiang X. The Effect of Endovascular Treatment of Renal Artery Stenoses on Coexistent Aneurysms Associated with Fibromuscular Dysplasia. J Vasc Interv Radiol. 2023 Aug;34(8):1353-1358.

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Study design

Single center retrospective

Funding Source

No funding

Setting

Academic center

Figure

Digital subtraction angiograms showing pretreatment (left) renal artery stenosis and aneurysm, and post-treatment (right) improvement in the aneurysm size after successful angioplasty.

Summary

Fibromuscular dysplasia (FMD) is an idiopathic, segmental, nonatherosclerotic, and noninflammatory arterial disease, which most commonly affects the renal and internal carotid arteries. Endovascular treatment for RAS and RAA in patients with FMD is limited, and the prognosis of RAA when RAS is treated remains unclear.

19 patients with coexistent RAS and RAA who underwent RAS-specific endovascular therapy were included in this study. Patients with coexistent RAS and RAA who underwent covered stent implantation or coil embolization for RAA were not included in this study. Patients who underwent endovascular treatment of the renal artery met all of the following indications: high blood pressure, angiographic evidence of 70% RAS, and a life expectancy of 2 years.

Patients were placed in the supine position, anesthetized locally with 2% lidocaine, and had baseline angiography performed using a 6-F guiding catheter. A balloon with a diameter 20% - 30% smaller than that of the reference was used on the first attempt. Procedural success of PTRA was defined as a residual stenosis of <50% in diameter after full balloon dilatation, and stent placement was performed when the blood flow was impeded by dissection.

The primary endpoints were the maximum diameter and improvement in renal artery occlusions, and the secondary endpoints were changes in blood pressure, number of antihypertensive drugs, renal function, and adverse events. Of the 19 patients, 2 had multifocal RAS, 17 had unifocal RAS, 14 had 1 RAA, 2 had 2 RAAs, and 3 had >2 RAAs. Twenty-one RASs were treated with PTRA alone, and the remaining 3 were treated with stent implantation.

The success rate of RAS-specific endovascular therapy was 100%, and the mean degree of stenosis decreased from 86.4% -11.9 to 12.6% -5.7%. The maximum diameter of all RAAs and SRAAs decreased significantly during a mean of 4.2 years, and the maximum diameter of non-SRAAs did not change. In the 19 patients with FMD, the systolic and diastolic blood pressures decreased, the number of antihypertensive medications decreased, and the serum creatinine level remained stable. The primary patency rates of PTRA and stent implantation were 89.5% and 100%, respectively.

Commentary

The authors evaluated the role of angioplasty or stenting for the treatment of renal artery stenosis with coexisting renal artery aneurysms in patients with FMD. There is limited information on this topic in the literature, and this study fills a gap in knowledge. The authors found that treating the renal artery stenoses also led to a regression in mean aneurysm size. They speculate that this is due to decreased blood pressure, although that was not directly tested. The study is limited by its single-center nature, small sample size, retrospective analysis, and long period of patient inclusion. Larger, multicenter studies would be useful to confirm these findings, and intra-arterial pressure measurements could be used to test the hypothesis that renal artery stenting leads to decreased arterial pressures within the renal artery aneurysms.

Post author

Timothy Huber, MD
Jefferson Radiology
@IR_Huber