Indications for Renal Artery Angioplasty and Stent Placement

Introduction

Percutaneous angioplasty and stent placement may be performed for renal artery stenosis causing renovascular hypertension or for preserving renal function. Regarding the former indication, up to 5% of patients with hypertension have atherosclerotic renal artery stenosis. The hypertension cure and response rates following stent placement range from 60% to 80%.

Regarding ischemic nephropathy (loss of renal function caused by renal ischemia from renal artery stenosis), there is improvement in renal function in about 25% to 35% and stabilization of renal function in the same percentage of patients. However, about 1/3 of patients showed deterioration of renal function.

Indications

Class I indications (there is evidence and/or general agreement that a given procedure or treatment is beneficial, useful, and effective):

• New-onset hypertension before 30 or severe hypertension after 55
• Accelerated, resistant, or maligant hypertension
• Development of new azotemia or worsening renal function after the administration of ACE inhibitors or angiotensin receptor blockers
• Unexplained atrophic kidney or a discrepancy in size between the two kidneys of >1.5 cm.
• Sudden, unexplained pulmonary edema: Patients with severe bilateral renal artery stenosis may present with recurrent pulmonary edema with or without left ventricular systolic dysfunction. Revascularization may decrease the recurrence of angina and pulmonary edema.

Class IIa indication (weight of evidence/opinion is in favor of usefulness/efficacy):

• Unexplained renal failure, including in individuals starting renal replacement therapy.

Class IIb indications (usefulness/efficacy is less well established by evidence/opinion):

• Multivessel coronary artery disease: Significant renal artery stenosis results in activation of the renin–angiotensin–aldostenrone system resulting in renovascular hypertension and increases cardiovascular and renal morbidity.
• Unexplained heart failure or refractory angina

Importantly, there is no evidence to support revascularization of asymptomatic high-grade renal artery stenosis incidentally diagnosed while imaging for unrelated causes (e.g., "drive-by" intervention during cardiac catheterization).

An important complication of renal artery angioplasty and stenting is acute renal failure, which occurs in 10%-20% of cases.

Future Directions

The angioplasty and stent for renal artery lesions (ASTRAL) trial compared the effect of maximal medical therapy plus revascularization to medical management alone on hypertension, renal function, and cardiovascular events in patients with atherosclerotic renal artery stenosis and renal failure. Results after one year showed no statistically significant difference in the serum creatinine, cardiovascular, and cerebrovascular events, hospitalization rates for cardiovascular causes, and risk-adjusted mortality rate between the two groups.

The cardiovascular outcomes in renal atherosclerotic lesions (CORAL) is ongoing and will compare the effect of optimal medical therapy plus stent supported angioplasty to optimal medical therapy alone on multiple cardiovascular and renal end points.

References

• Hirsch AT, Haskal ZJ, Hertzer NR, et al. (2006) ACC/AHA 2005 Practice Guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric, and abdominal aortic): a collaborative report from the American Association for Vascular Surgery/Society for Vascular Surgery, Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Peripheral Arterial Disease): endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation; National Heart, Lung, and Blood Institute; Society for Vascular Nursing; TransAtlantic Inter-Society Consensus; and Vascular Disease Foundation. Circulation 113(11):e463–e654.
• Martin EC, Mattern RF, Baer L, Fankuchen EI, Casarella WJ (1981) Renal angioplasty for hypertension: predictive factors for long-term success. AJR Am J Roentgenol 137(5):921–924
• Thatipelli M, Misra S. Endovascular intervention for renal artery stenosis. Abdom Imaging. 2009 Sep 29.