Updated: 12/14/2019

Renal Artery Stenosis

Topic
Review Topic
0
0
Questions
3
0
0
Evidence
1
0
0
Snapshot
  • A 59-year-old man with a history of hypertension presents to his primary care physician for blood pressure management. He has tried lisinopril, hydrochlorothiazide, and losartan, and had minimal effect. He has a strong family history of cardiovascular disease. Physical examination is notable for a bruit in the right flank. Routine bloodwork shows an elevated creatinine. Preparations are made for a doppler ultrasound of the renal arteries.
Introduction
  • renal artery stenosisClinical definition
    • narrowing of one or both renal arteries
      • this often causes renovascular hypertension
      • grade 1 – RAS (Renal artery stenosis) with no clinical symptoms
      • grade 2 – RAS with controlled hypertension
      • grade 3 – RAS with resistant hypertension, abnormal renal function, or volume overload
  • Epidemiology
    • prevalence
      • 7% in the United States
      • present in up to 1/3 of patients with malignant or resistant hypertension
    • demographics
      • atherosclerotic disease
        • patients > 50 years of age
      • fibromuscular dysplasia
        • young women
    • risk factors
      • atherosclerosis and its risk factors (e.g., smoking and fatty diet)
      • fibromuscular dysplasia
      • kidney transplant patients
      • high calcium or phosphorous levels
      • high low-density lipoprotein cholesterol levels
  • Pathophysiology
    • pathophysiology
      • narrowing of artery lumen due to
        • atherosclerosis
        • fibromuscular dysplasia
      • narrowed arteries lead to reduced renal perfusion
        • reduced perfusion leads to activation of renin-angiotensin system
          • increased renin → hypertension, hypokalemia, and hypernatremia
        • bilateral renal stenosis can lead to volume overload
          • heart failure
          • pulmonary edema
  • Associated conditions
    • other manifestations of atherosclerotic disease
      • carotid artery disease
      • lower extremity artery disease
      • coronary heart disease
  • Prognosis
    • prognostic variable
      • negative
        • elevated serum creatinine
        • comorbid heart disease
        • comorbid chronic obstructive pulmonary disease (COPD)
    • survival with treatment
      • 91% at 1 year
      • 67% at 5 years
      • 41% at 10 years
Presentation
  • History
    • hypertension before 30 years of age
      • consider fibromuscular dysplasia in young women with abrupt onset of hypertension
    • resistant or malignant hypertension
    • worsening renal function after taking an ACE inhibitor or angiotensin receptor blocking (ARB) agent
      • may indicate bilateral RAS because ACE inhibitors and ARBs further decrease glomerular filtration rate and worsens renal function
    • sudden unexplained volume overload (heart failure or pulmonary edema)
  • Symptoms
    • primary symptoms
      • hypertension
  • Physical exam
    • extremities
      • may have edema if volume overloaded
    • abdomen
      • abdominal or flank bruit through systole and diastole
Imaging
  • Ultrasound
    • indications
      • often initial imaging in those < 60 years of age in patients with suspected RAS
    • sensitivity and specificity
      • sensitivity 88-93%
      • specificity 82-89%
  • CT angiography
    • indications
      • in patients with normal renal function and suspected RAS
    • sensitivity and specificity
      • sensitivity 90%
      • specificity 94%
  • MR angiography in patients with renal insufficiency 
    • indications
      • in patients with renal insufficiency and suspected RAS
    • sensitivity and specificity
      • sensitivity 75-97%
      • specificity 64-93%
  • Invasive catheter angiography
    • indications
      • only indicated if high suspicion of disease but inconclusive imaging or if revascularization is planned
    • gold standard for diagnosis
Studies
  • Labs
    • serum creatinine to assess renal function
      • elevated creatinine may indicate atherosclerosis-associated RAS
      • normal creatinine may indicate fibromuscular dysplasia-associated RAS
    • urine protein to assess renal function
      • typically below nephrotic range (< 3.5 g in 24 hours)

  • Histology
    • fibromuscular dysplasia
      • medial fibroplasia
  • Diagnostic criteria
    • reduction of diameter of > 60%
    • string-of-beads appearance on angiography in fibromuscular dysplasia
Differential
  • Essential hypertension
    • typically responsive to therapy
  • Primary hyperaldosteronism
    • high levels of aldosterone
  • Obstructive sleep apnea
    • lethargy and fatigue
Treatment
  • Medical
    • ACE-inhibitors or ARBs
      • indications
        • persistent hypertension in patients with RAS
      • contraindicated in bilateral RAS or RAS in patients with single kidney
    • calcium channel blockers or β-blockers
      • given if patients do not respond to ACE-inhibitors or ARBs
    • manage lipid disorders with statins
  • Operative
    • revascularization
      • indications
        • severe complications of RAS
          • unexplained heart failure
          • unexplained pulmonary edema
          • chronic kidney disease
          • inadequately controlled hypertension
      • outcomes
        • may not improve outcomes in those with atherosclerotic RAS
        • cures up to 58% of hypertension in patients with fibromuscular dysplasia-associated RAS
      • complications
        • contrast-induced acute kidney injury or allergic reaction (< 3%)
        • bleeding, hematoma, or arteriovenous fistula
Complications
  • Renal dysfunction can progress to end-stage renal disease
    • incidence
      • 4% in one study of 68 adults over 39 months
    • treatment
      • dialysis and kidney transplant
 
 

Please rate topic.

Average 2.7 of 3 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Questions (3)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Volume  
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Urine  
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2
Calculator

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

You have 100% on this question.
Just skip this one for now.

(M2.RL.174) A 67-year-old man with a 55-pack-year smoking history, diabetes type II, and hyperlipidemia presents to his primary care clinic for an annual exam. He has no complaints. He reports that his blood glucose has been under tight control and that he has not smoked a cigarette for the past 5 months. His temperature is 97.5°F (36.4°C), blood pressure is 182/112 mmHg, pulse is 85/min, respirations are 15/min, and oxygen saturation is 95% on room air. Physical examination is notable for bruits bilaterally just lateral of midline near his umbilicus. The patient is started on anti-hypertensive medications including a beta-blocker, a thiazide diuretic, and a calcium channel blocker. He returns 1 month later with no change in his blood pressure. Which of the following is the best next step in management? Review Topic

QID: 104180
1

CT abdomen/pelvis

3%

(1/33)

2

Increase dose of current blood pressure medications

9%

(3/33)

3

Lisinopril

67%

(22/33)

4

Renal ultrasound with Doppler

6%

(2/33)

5

Surgical revascularization

12%

(4/33)

M2

Select Answer to see Preferred Response

SUBMIT RESPONSE 4
ARTICLES (3)
Topic COMMENTS (10)
Private Note