Doppler Sonography in the Detection of Significant Renal Artery Stenosis

Background Systemic hypertension is a major risk factor both for stroke and for myocardial infarction. The search for underlying treatable cause is a part of the management of a hypertensive patient. Renal vascular hypertension is the most common form of potentially curable hypertension and if untreated may terminate in renal failure. It has been estimated that 10% to 20% of new patients presenting with end-stage renal disease have treatable renal vascular disease. The purpose of screening strategies is to identify significant renal artery stenosis (RAS) in earlier stages before irreversible damage or loss of renal mass occurs. Due to the relatively low prevalence of RAS in the hypertensive population an inexpensive, accurate and non-invasive screening test is required in patients with normal or impaired renal function. Duplex Doppler sonography (DUS) is non-invasive screening test for the detection of RAS. It combines visualization of renal arteries with measurement of various hemodynamic factors within the kidney. Recent studies have shown improvement of diagnostic values of DUS. Encouraging results were obtained by the combination of extrarenal and intrarenal Doppler scanning (2,3,4,5). The aim of the study was to determine the usefulness of DUS of the renal arteries in identifying patients with RAS >50%.