Renal Artery Intervention: Current State of the Art | SCAI

Timir Paul, MD, PhD, FSCAI; Hady Lichaa, MD, FSCAI; Konstantinos Dean Boudoulas, MD, FSCAI


Approximately 6.8% of healthy adults aged >65 years have renal artery stenosis (RAS) with a higher prevalence among those with cardiovascular (CV) risk factors, which is a marker of poorer prognosis.It is estimated that ~10% of hypertensive patients in the US have resistant hypertension, and RAS is a common secondary cause (5%-34%).The CORAL trial demonstrated that renal artery stenting is not associated with improvement of major adverse CV events3; however, for certain indications, as described in this Tip of the Month (TOTM), renal intervention remains an important therapeutic option. In addition, this TOTM will discuss some practical tips for renal artery intervention.

Table 1: ACC/AHA Guidelines on Screening, Diagnostic Modalities, and Treatment/ Revascularization of RAS4,5

Screening and Diagnostic Modalities

Treatment/Revascularization of RAS

ACC/AHA Class I Indications

  1. Hypertension before age 30 or severe hypertension after age 55
  2. Resistant, accelerated, and malignant hypertension
  3. New azotemia or worsening renal function after administration of ACEIs/ARBs
  4. Sudden unexplained pulmonary edema
  5. Unexplained atrophic kidney or discrepancy in size between the kidneys > 1.5 cm

Modalities of Screening (Class I)

  • Duplex ultrasound
  • CT angiogram*
  • MRA*
  • Renal angiography (gold standard)

*CT and MRA may be suboptimal for fibromuscular dysplasia (FMD).

Aggressive Risk Factors Modification as a Class I Indication

Indications for Revascularization

Class I

  • Significant RAS and recurrent unexplained heart failure or sudden unexplained pulmonary edema

Class IIa

  • Hemodynamically significant RAS and:
    • Unstable angina
    • Hypertension:
      • Accelerated, resistant, or malignant hypertension
      • Hypertension with an unexplained unilateral small kidney
      • Hypertension with an intolerance to medication
    • Progressive chronic kidney disease with bilateral RAS or RAS to a solitary functioning kidney

ACC: American College of Cardiology; AHA: American Heart Association; ACEIs: angiotensin-converting enzyme inhibitors; ARBs: angiotensin receptor blockers; MRA: magnetic resonance angiography; CT: computed tomography

Patient Selection

Appropriate patient selection is the key for optimal clinical outcomes of renal artery revascularization. Treating hemodynamically insignificant lesions, symptoms not related to RAS, and the concomitant presence of renal parenchymal disease are predictors of poor outcomes.

Table 2: Hemodynamic Criteria for Significant RAS and Predictors of Advanced Nephropathy

Hemodynamic Criteria for Significant RAS4,5

Predictors of Advanced Nephropathy (Nonviable Kidney)

  1. Angiographic stenosis > 70%
  2. >70% stenosis by IVUS
  3. Stenosis of 50%–70% by visual estimation with:
    • Hyperemic systolic gradient > 20 mm Hg, or
    • Resting mean gradient > 10 mm Hg
  4. Stenosis 50%-70% with renal Pd/Pa ≤0.90 or FFR ≤0.80
  • Proteinuria >1 gm/day
  • Kidney length < 10 cm
  • RRI > 0.8
  • Serum creatinine, which is less reliable in the prediction of nephropathy
  • Decreased renal frame count (<30) and renal blush grade <1

IVUS: intravascular ultrasound; Pd/Pa: ratio of mean distal to lesion to proximal pressure; FFR: fractional flow reserve; RRI: renal resistive index

Procedural Tips and Tricks

  • Access:
    • A 6F to 7F femoral sheath depending on the selected stent size and type (uncovered vs. covered)
    • A 5F/6F or 6F/7F thin-walled radial sheath as a good alternative (left vs. right radial depending on the patient’s height, innominate artery tortuosity, and aortic arch type)
  • Guide catheter:
    • Femoral:
      • A 65 cm 6F or 7F guide with a curved tip (i.e., Internal Mammary [IM], Renal Double Curve [RDC], Hockey Stick)
      • Other options: 6F to 7F sheathless guides to minimize the femoral arteriotomy size; 7F deflectable tip sheaths mostly for the use of a covered stent
    • Radial: A 100 cm to 125 cm main pulmonary artery (MPA) or Judkins right (JR)4 guide depending on the patient’s height, left vs. right access, and renal artery takeoff
  • IVUS: Improvement of procedural safety, the lesion preparation strategy, the choice of stent type/size, and the post-dilation decision6
  • Carbon dioxide (CO2) gas: Very helpful in the avoidance of iodinated contrast use, especially when combined with IVUS7
  • Renal FFR: Any 0.014” pressure wire for use in measuring renal FFR with papaverine or dopamine, with <80 being significant8
  • Embolization-prevention techniques: Utilization of techniques such as guide catheter telescoping using a diagnostic catheter or the no-touch technique
  • Balloon (definitive therapy for renal FMD):
    • Femoral:
      • 014” compatible semi-compliant or noncompliant balloons
      • Off-label use of cutting and scoring balloons or intravascular lithotripsy, which may be useful depending on lesion morphology
      • Availability of a dedicated ostial flaring balloon, if needed
      • No data on drug-coated balloons
    • Radial:
      • A 12 mm-20 mm 0.014” compatible 145 cm-155 cm monorail shaft (compliant or noncompliant)
      • Use of a short hemostatic valve (i.e., Checkflo [Cook Medical]), which allows reach in non-ostial lesions
    • Stent:
      • Femoral:
        • A 0.014” compatible balloon-expandable, bare-metal stent
        • Off-label use of dedicated coronary thick-strutted, left main drug-eluting stents (i.e., Megatron [Boston Scientific])
      • Radial:
        • A 0.014” compatible 135 cm-150 cm monorail shaft, balloon-expandable bare-metal stent
        • Off-label use of 145 cm monorail shaft coronary drug-eluting stent or coronary-covered bare-metal stent


Screening for RAS should be performed as per current ACC/AHA guidelines for aggressive risk factor modification and optimal medical therapy. For patients with severe RAS, who have uncontrolled hypertension on ≥ 3 medications — including a diuretic — or are intolerant to medications, renal artery stenting remains an important option.


  1. Hansen KJ, Edwards MS, Craven TE, et al. Prevalence of renovascular disease in the elderly: a population-based study. J Vasc Surg. 2002 Sep;36(3):443-51.
  2. Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2018 Jun;71(6): 1269-1324.
  3. Cooper CJ, Murphy TP, Cutlip DE, et al. Stenting and medical therapy for atherosclerotic renal-artery stenosis. N Engl J Med. 2014 Jan 2;370(1):13-22.
  4. Anderson JL, Halperin JL, Albert NM, et al. Management of patients with peripheral artery disease (compilation of 2005 and 2011 ACCF/AHA guideline recommendations): a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2013 Apr 2;127(13):1425-43.
  5. Bhalla V, Textor SC, Beckman JA, et al. Revascularization for Renovascular Disease: A Scientific Statement From the American Heart Association. Hypertension. 2022 Aug;79(8):e128-e143.
  6. Dangas G, Laird JR Jr, Mehran R, et al. Intravascular ultrasound-guided renal artery stenting. J Endovasc Ther. 2001 Jun;8(3):238-47.
  7. Kawasaki D, Fujii K, Fukunaga M, et al. Safety and efficacy of carbon dioxide and intravascular ultrasound-guided stenting for renal artery stenosis in patients with chronic renal insufficiency. Angiology. 2015 Mar;66(3):231-6.
  8. Subramanian R, White CJ, Rosenfield K, et al. Renal fractional flow reserve: a hemodynamic evaluation of moderate renal artery stenoses. Catheter Cardiovasc Interv. 2005 Apr;64(4):480-6.

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