Nephrology

Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN 37232-2372, USA.
Ischemic renal disease is defined as a clinically significant reduction in glomerular filtration rate in patients with hemodynamically significant renal artery stenosis. The most common etiology for this is atherosclerotic renal artery disease. The three major clinical settings in which one must suspectischemic renal disease include acute renal failure precipitated by the treatment of hypertension particularly with angiotensin-converting enzyme inhibitors; progressive azotemia in a patient with known renal vascular hypertension treated medically; and unexplained progressive azotemia in an elderly patient with refractory hypertension and other evidence of atherosclerotic disease. Prevalence ofischemic renal disease secondary to atherosclerosis can be estimated from the incidence of atherosclerotic renal artery lesions leading to renal vascular hypertension and the natural history of these lesions. Autopsy series, arteriography studies, and review of populations of patients in end-stage renal disease programs all suggest that ischemic renal disease has a high and increasing prevalence inour aging population.
Department of Medicine, Duke University Medical Center, Durham, NC 27710.
In addition to its role in secondary hypertension, ischemic renal disease is becoming recognized as a significant cause of renal insufficiency. The prevalence and natural history of this disease remain unknown due to difficulty in identification of the process. There are several scenarios that mayhelp alert the clinician to the presence of atherosclerotic renovascular disease. In hypertensive patients, poorly controlled blood pressure on several medications or rapid acceleration of hypertension can suggest renovascular disease. In addition, high-grade retinopathy or abdominal bruits seem to be associated with this condition: bruits have the highest positive predictive value of the clinicalsigns. Renal artery stenosis also may be related to rapidly progressive renal failure. The classic association is renal failure after use of angiotensin-converting enzyme inhibitors; however, acute renal failure induced through any sudden therapeutic decrease in blood pressure may imply the presence of renal artery stenosis. Unexplained azotemia in the elderly patient also has been associated withrenovascular disease. It is possible that the majority of patients with renal artery stenosis are those with a clinically silent process. Advanced age, peripheral atherosclerotic vascular disease, and coronary artery disease may all have a high association with stenosis of one or both renal arteries. It is nevertheless unknown whether a radiographically detected lesion implies current or futureclinical complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Textor SC, Wilcox CS.
Divisions of Hypertension and Nephrology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA. textor.stephen@mayo.edu
Chronic azotemic renovascular disease is common in patients with atherosclerosis. Its prevalence appears to be increasing in the aging population. How often it is the primary cause ofend-stage renal disease (ESRD) is not yet certain. Some studies suggest that 10%-40% of elderly hypertensive patients with newly documented ESRD and no demonstrable primary renal disease have significant renal artery stenosis (RAS). Atherosclerotic vascular occlusive disease of the renal arteries does progress, but current rates of progression and occlusion are lower than those reported a decadeago. Methods of identifying patients whose renal function is at true risk from vascular occlusive disease and determining who will benefit from intervention remain elusive. The presence of RAS in an azotemic patient can be assessed with noninvasive and risk-free radiologic techniques, including Duplex doppler velicometry and magnetic resonance angiography. Functional tests that predict the change...