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renal artery stenosis (RAS)

Etiology: 1) atherosclerotic plaques* 2) fibromuscular dysplasia, stenosis* a) more common in women b) patients under 50 3) thrombosis 4) embolism 5) renal arterial dissection/aneurysm 6) arteritis 7) extrinsic compression 8) occlusion by foreign body 9) coarctation of aorta 10) arteriovenous fistula 11) post irradiation stenosis 12) post transplant stenosis * 2 most common causes Epidemiology: 1) uncommon 2) atherosclerotic disease: > 50 years of age 3) fibromuscular dysplasia: < 30 years of age Pathology: - the perceived reduction in renal perfusion results in release of renin & activation of the renin-angiotensin-aldosterone axis Clinical manifestations: 1) epigastric, subcostal or flank bruits 2) accelerated hypertension 3) unilateral small kidney 4) sudden development or worsening of hypertension - diastolic blood pressure > 120 mm Hg 5) hypertension & unexplained renal failure 6) hypertension refractory to 3-drug medical therapy 7) impairment of renal function in response to ACE inhibitor 8) extensive atherosclerosis evident in other organ systems 9) flash pulmonary edema with uncontrolled hypertension 10) high-grade hypertensive retinopathy 11) ischemic nephropathy - glomerulonephritis 12) secondary hyperaldosteronism Laboratory: - increased serum creatinine - further increased after treatment with ACE inhibitor or ARB - increased serum aldosterone Special laboratory: 1) plasma renin & plasma aldosterone are elevated [2] 2) renal vein renin levels - ratio involved/contralateral side > 1.5 suggests significant lesion 3) renin activity weighted analysis point system 4) screening for renovascular hypertension (sensitivity/specificity) a) captopril test 95/95 b) captopril scan (scintigraphy) 80/100 c) renal scan 75/75 d) IVP 75/85 e) digital subtraction angiogram 90/90 f) renal vein renin 75/95 * routine testing for older adults with cardiovascular disease not recommended [2] Radiology: 1) renal angiography for fibromuscular dysplasia (gold standard)* - 'string of beads' appearance consistent with fibromuscular dysplasia - release of cholesterol emboli is a risk in patients with atherosclerosis [2] 2) computed tomographic angiography [10] - sensitivity suboptimal for detecting distal renal artery stenosis, a common location for fibromuscular dysplasia [15] 3) captopril scan for screening (33-47/92-88)* 4) doppler ultrasonography of renal arteries (initial imaging) [14] - captopril enhanced doppler sonography (63-79/95-80)* 5) gadolinium-enhanced magnetic resonance angiography (MRA) (90-95/80-82)*# 6) digital subtraction angiography [10] * sensitivity/specificity (50% - >70% stenosis) relative to angiography # test of choice, Veterans Administration, Mather Complications: - unilateral or bilateral renal artery stenosis can cause hypertension refractory to antihypertensives Management: 1) NOT ALL cases of hypertension & renal artery stenosis are due to renovascular disease; the two conditions can coexist 2) many patients can control blood pressure with medical therapy (primary therapy in most patients) [2] 3) angioplasty a) symptomatic fibromusclar dysplasia without aneurysm or dissection (see fibromusclar dysplasia) b) angioplasty with stent placement no better than medical therapy for atherosclerotic renal artery stenosis [8,9,11] 4) aggressive control of cardiovascular risk factors a) control of hypertension 1] use of ACE inhibitors or ARBs controversial - ACE inhibitor for hypertension [2] 2] earlier literature recommends avoiding ACE inhibitors 3] ACE inhibitors may increase serum creatinine levels in patients with bilateral renal artery stenosis [2], but their effect on ESRD is not as clear b) statins & antiplatelet therapy (clopidogrel or aspirin) may be used to treat peripheral vascular disease [6] c) control of diabetes mellitus d) diet & life style measures 1] weight reduction 2] smoking cessation

Related

fibromuscular dysplasia renal artery

General

arterial stenosis visceral arterial disease kidney disease; renal disease

References

  1. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 277
  2. Medical Knowledge Self Assessment Program (MKSAP) 11, 15, 16, 17, 18, 19. American College of Physicians, Philadelphia 1998, 2009, 2012, 2015, 2018, 2021. - Medical Knowledge Self Assessment Program (MKSAP) 19 Board Basics. An Enhancement to MKSAP19. American College of Physicians, Philadelphia 2022
  3. Journal Watch 20(13):103, 2000
  4. Journal Watch 21(20):161-62, 2001 Vasbinder et al, Ann Intern Med 135:401, 2001
  5. Journal Watch 22(1):2, 2002 Qanaduu et al, AJR Am J Roentgenol 177:1123, 2001
  6. Balk E et al, Effectiveness of management strategies for renal artery stenosis: a systematic review. Annals of Intern Med 2006, 145:901 PMID: 17062633
  7. van Jaarsveld BC et al, The effect of balloon angioplasty on hypertension in atherosclerotic renal-artery stenosis. N Engl J Med 2000, 342:1007 PMID: 10749962
  8. Bax L et al Stent Placement in Patients With Atherosclerotic Renal Artery Stenosis and Impaired Renal Function Annals of Internal Medicine, 2009 150(12)840-848 PMID: 19414832 http://www.annals.org/content/150/12/840.full
  9. Wheatley K et al for The ASTRAL Investigators. Revascularization versus medical therapy for renal-artery stenosis. N Engl J Med 2009 Nov 12; 361:1953. PMID: 19907042
  10. Dworkin LD, Cooper CJ. Clinical practice. Renal-artery stenosis. N Engl J Med 2009; 361:1972-1978; November 12, 2009. PMID: 19907044
  11. 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 PMID: 24245566 Free PMC Article http://www.nejm.org/doi/full/10.1056/NEJMoa1310753 - Bittl JA. Treatment of atherosclerotic renovascular disease. N Engl J Med 2013 Nov 18 PMID: 24245567 http://www.nejm.org/doi/full/10.1056/NEJMe1313423
  12. Geriatric Review Syllabus, 8th edition (GRS8) Durso SC and Sullivan GN (eds) American Geriatrics Society, 2013
  13. Agency for Healthcare Research and Quality (AHRQ) Renal Artery Stenosis Management Strategies: An Updated Comparative Effectiveness Review. Executive Summary - Aug. 16, 2016 https://www.effectivehealthcare.ahrq.gov/search-for-guides-reviews-and-reports/?pageaction=displayproduct&productID=2276
  14. Dworkin LD, Cooper CJ. Clinical practice. Renal-artery stenosis N Engl J Med. 2009 Nov 12;361(20):1972-8. PMID: 19907044 PMCID: PMC4812436 Free PMC article
  15. Gornik HL, Persu A, Adlam D First International Consensus on the diagnosis and management of fibromuscular dysplasia. Vasc Med. 2019 Apr;24(2):164-189 PMID: 30648921
  16. Herrmann SM, Textor SC. Renovascular hypertension. Endocrinol Metab Clin North Am. 2019;48:765-778. PMID: 31655775