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

Duplex ultrasonography screening for renal artery stenosis has been the object of guidelines published by four societies designed to optimize the cost-effectiveness of the examination.

Objectives: 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.

Material and methods: 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.

Results: 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.

Conclusion: 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.