Upload
-
View
23
Download
3
Embed Size (px)
DESCRIPTION
Renal artery stenosis
Citation preview
Diagnosis of Renovascular Hypertension
Cholatip Pongskul
Characteristics of atherosclerotic and fibromuscular dysplasia
Variable Atherosclerotic Fibromuscular dysplasia
Age at presentation Older(>50 yr) Usually young(<40 yr)
Sex Either Usually female
Lesion location Ostial, proximal, middle Middle or distal
BP response to revascularization
Unclear Normotensive in most patients
Atherosclerotic Fibromuscular dysplasia
Elderly>50 Younger<40,femaleResponse to correction
Pathophysiology of renal artery stenosis
Who should be tested for renovascular hypertension?
• 45-year-old man, uremia, BP 160/90 mmHg, proteinuria, kidney 8.5, 8 cm
• 70-year-old man, smoker, hypertension, dyslipidemia, presented with pulmonary edema, Cr=1.4 mg/dl
• 60-year-old woman with pulmonary edema, BP 180/100 mmHg, Cr=1.2 mg/dl
Who Should be tested
What testShould be performed
How
to interpret the result
Who
• Onset of severe hypertension after 55• Unexplained deterioration of kidney function
– Rising > 50%, 1 week, ACEI• Severe hypertension in diffuse atherosclerosis• Severe hypertension with asymmetry kidney >
1.5 cm• Severe hypertension with flash pulmonary
edema, refractory CHF• Systolic-diastolic bruit at one side
Test or not test?
• Medication is effective in renovascular hypertension
• Who will benefit from correction?
• Testing associated with potential risk• Correction procedure associated with
morbidity/mortality
Test should be performed in patient with high likelihood of benefit
from procedure
High likelihood of benefit from procedure
• Short duration• Failure of medical Rx, in patient with high
likelihood of renovascular hypertension• Intolerance to optimal medical therapy• Progressive renal failure• Suspected fibromuscular dysplasia• Recurrent flash pulmonary edema
Gold Renal angiography
More than 50% stenosis
Other tests• Duplex sonography• CT angiogram• MRA
Duplex doppler sonography
Functional and anatomical
Peak200 cm/sec
Peak systolic velocitySensitivity 85, specificity 92%Positive predictive value 84%
Positive test: more informative than negative test
Resistive index(1-end diastolic velocity)/PSV
Predict outcome after revascularization
Limitation
Time consuming operator dependent
Obese patient
CT angiography
Excellent sensitivity and specificityLimitation in distal stenosis (FMD)
Magnetic resonance angiography
MRA• Almost 100% sensitivity!• Nephrogenic systemic
fibrosis?
Functional assessment
Captopril renography: less commonly usedLittle predictive value
Not for screening test!
Selecting a diagnostic test
• Local availability• Expertise with each technique• Renal insufficiency?
Who
New onset HT>55 yrDeterioration GFRAsymmetry kidneyFlash pulmonary edema
Test
Failure medicalFMD?Progressive renalfailure
Benefit fromcorrection