Doppler ultrasonography of the renal artery: Guidelines and predictive factors for the presence of a tight stenosis. Retrospective analysis of 450 consecutive examinations

Abstract

To determine how well guideline indications for ultrasonography matched with requests and results in our university hospital; to determine whether compliance with guidelines was predictive of renal artery stenosis; to identify guidelines predictive of presence of stenosis; and to determine whether other predictive factors can be recognized. Requests and results of 450 Duplex ultrasonography examinations of the renal arteries performed from January 1st 2014 to December 31st 2015 were compared with published guidelines. At least one guideline indication was identified for 212 of the 450 examinations performed (47.1%). Among these examinations, renal artery stenosis≥70% was identified in 18 patients (8.0%). No case of stenosis was identified during examinations performed outside guideline indications. Factors predictive of stenosis were: compliance with guidelines (OR=21.86 [2.88; 165.8]). Predictive guidelines were: resistant hypertension in spite of appropriate treatment (OR=3.85, [1.44; 10.33], P=0.011), accelerated hypertension (OR=7.30, [1.40; 37.99], P=0.049), sudden unexplained pulmonary edema (OR=7.30, [1.40; 37.99], P=0.049), unexplained renal insufficiency (OR=3.58, [1.37; 9.37], P=0.011), unexplained renal hypotrophy (OR=16.69, [4.38; 63.69], P<0.001), renal asymmetry (OR=4.32, [1.45; 12.85], P<0.016). No other factor was predictive of renal stenosis. These examinations had therapeutic consequences in only 50% of patients. This study confirms the relevance of published guidelines. The diagnostic-effectiveness of Duplex ultrasonography examinations to search for renal artery stenosis depends upon compliance with these guidelines.