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At what stenosis percentage does renal occlusive disease cause hypertension? 20% 40% 60% 80% 60% (HTN from increased rennin release). What is the leading cause of renovascular hypertension? Fibromuscular dysplasia Radiation vasculitis Thromboembolism Atherosclerosis
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At what stenosis percentage does renal occlusive disease cause hypertension? • 20% • 40% • 60% • 80% • 60% (HTN from increased rennin release)
What is the leading cause of renovascular hypertension? • Fibromuscular dysplasia • Radiation vasculitis • Thromboembolism • Atherosclerosis • Atherosclerosis (nearly 90% of cases)
In renovascular disease, where do atherosclerotic plaques most commonly begin? • Adjacent aorta • Proximal renal artery • Distal renal artery • Adjacent aorta
Most commonly, the atherosclerotic process begins in the adjacent aorta with “spillover” plaque that encroaches into the proximal renal artery, resulting in “orificial” renal artery stenosis. Plaque extends into the proximal third of the artery, but the more distal vessel remains relatively free of disease. Atherosclerosis involves the renal artery origins bilaterally in more than half of patients.
Which of the following groups should be routinely screened for renovascular occlusive disease? • Hypertensive pediatric patients • Women between 25 and 50 years of age • Patients over 50 with recent sudden change in blood pressure • Patients with worsening azotemia with antihypertensive treatment • Patients with a dramatic normalization of blood pressure by an ACE inhibitor • All of the above • All of the above
What is the diagnostic test of choice in the evaluation of renovascular occlusive disease? • Selective venous renin sampling • Selective ureteral catheterization • Renal scintigraphy with captopril • MRI • Angiography • MRI
Because they are logistically cumbersome, physiologic studies have increasingly yielded to anatomic diagnosis, relying on ultrasound and MRI for initial detection of disease and then arteriography for confirmation and possible catheter-based intervention if appropriate. MRI is becoming the anatomic imaging modality of choice in many centers where gadolinium-enhanced scanning has provided an expeditious, objective, and safe means of identifying renal artery disease. Ultrasound is very operator dependant, and sensitivity varies widely between centers. CT is also available, using spiral technique for highresolution imaging of the renal arteries. This method is very accurate but requires use of intravenous contrast material with a small risk of renal toxicity.
What is the initial treatment for renovascular occlusive disease? • Medical • Angioplasty / Stents • Endarterectomy • Bypass • Medical
Initial therapy of renovascular hypertension is medical. β-Adrenergic blockers, diuretics, vasodilators, and ACE inhibitors are commonly used with success. A more aggressive therapeutic approach is justifiable if blood pressure control requires increasing doses of two or three medications or if renal function deteriorates while on antihypertensive medications, particularly ACE inhibitors.
Which of the following attributes is not predictive of therapeutic success after revascularization? • Arterial stenosis greater than 60% • Poststenotic dilation • Evidence of delayed parenchymal function • Kidney diameter of 4cm • Kidney diameter of 4cm
In the proper clinical setting, the presence of a small kidney with arterial stenosis greater than 60%, poststenotic dilatation, and evidence of delayed parenchymal function is highly predictive of therapeutic success after revascularization. . Kidneys that are smaller than 6 cm are generally not salvageable, and nephrectomy may be considered.
The long term patency rate of percutaneous intervention of fibromuscular dysplasis is: • 10% • 25% • 50% • 75% • 90% • 90%
Long-term results after percutaneous transluminal renal angioplasty are excellent for patients with fibromuscular dysplasia. Recurrent stenosis occurs in approximately 10% of patients but is most often amenable to repeat angioplasty. Lesions involving branch arteries or bifurcation areas are less likely to be successfully treated and more likely to be associated with complications after attempted angioplasty.
The long-term patency rate for aortic endarterectomy for renal artery orificial occlusive disease is: • 10% • 25% • 50% • 75% • 90% • 90%
Endarterectomy of the renal artery orifice is a very durable procedure. Serial study of bypass patency indicates as many as 88% of grafts remain patent for as long as 20 years after surgery. Success rates for percutaneous intervention of atherosclerotic plaques are: hypertensive cure in 20% to 25%, improvement or stabilization in 50% to 60%, and failure of treatment in 15% to 20%.
Angiontension I is converted to angiontension II by ACE in what organ? • Liver • Kidney • Lung • Muscle • Lung