#6682 RENAL ARTERY STENOSIS: A SINGLE CENTRE STUDY
Authors: Panaro Laura , Trezzi Matteo , Mocka Sonila , Marchini Michele , Viazzi Francesca , Manenti Lucio 
Published: June 2023

Abstract

Background and Aims
Renal artery stenosis (RAS) is present from 1% to 5% in people affected by arterial hypertension and it is often associated with peripheral artery disease and coronary artery disease; as the matter of fact, it is commonly found in people undergoing cardiac catheterization (18-20%) or angiography for aorto-iliac and lower extremities diseases. The major cause of renal artery stenosis is an atherosclerotic lesion localized in the proximal segment or to the ostium. Clinical presentations are renovascular hypertension and ischemic nephropathy. The aim of the study is to define either endovascular treatment gives a significant benefit on renal function and blood pressure control, when associated to medical therapy.

Method
This is a retrospective study focused on patients who underwent renal artery angioplasty and stenting in the last ten years, from November 2011 to April 2021 in the Nephrology Department, at Sant'Andrea Hospital, La Spezia (Italy). The primary outcome was kidney function, while secondary outcomes were blood pressure and the number of antihypertensive drugs one year after the revascularization. Patients included in the study had uncontrolled and refractory arterial hypertension (PA ≥140/90 mmHg) and/or progressive worsening of renal function, secondary to bilateral or unilateral stenosis in one functional kidney, that was identified at the color-doppler ultrasound examination by a peak systolic velocity (PSV) &gt;200 ml/min and an aortic-renal ratio &gt;3,5. We found 36 patients who had these characteristics. They were all affected by chronic kidney disease (CKD) (mean±SD eGFR 25,3±15,3 ml/min/1,73 m2) equally divided into stage 3 (33%, eGFR 30-60 ml/min/1,73 m2), stage IV (31% eGFR 15-29 ml/min/1,73 m2) and stage V (36%, eGFR &lt;15 ml/min/1,73 m2).

Results
Kidney function, measured as serum creatinine (SCr) (mg/dl), improved immediately after the revascularization (mean ± SD SCr after vs before 2,52 ± 1,61 vs 3,31 ± 2,47 mg/dl p&lt;0.05), after 30 days (mean ± SD SCr after vs before creat. 2,36 ± 1,53 vs 3,19 ± 2,39 mg/dl p&lt;0.05) and after one year (mean ± SD SCr after vs before creat. 2,04 ± 1,16 vs 2,99 ± 2,40 mg/dl p&lt;0.05) (Fig. 1). Regarding arterial hypertension, a significant reduction of both systolic (SBP) and diastolic (DBP) blood pressure was detected in the subgroup of people under 75 years old (mean ± SD SBP after vs before, 144,62 ± 12,55 vs 168,18 ± 36,40 mmHg, p&lt; 0,01; after one year vs before, 143,95 ± 21,10 vs 167,83 ± 38,16 mmHg, p&lt;0.05) (mean ± SD DBP after vs before, 73,62 ± 9,62 vs 83,07 ± 21,75 mmHg, p&lt; 0,05; after one year vs before 75,20 ± 9,02 vs 83,33 ± 23,10 mmHg, p = 0.07) (Fig. 2). The number of antihypertensive drugs dropped immediately after the angioplasty (mean ± SD tablets after vs before 2,28 ± 1,11 vs 3,21 ± 1,43, p&lt;0.01), while after one year there was not a significant increase of therapy (mean ± SD tablets after one year vs before, 3,00 ± 1,41 vs 3,23 ± 1,42, p = 0,47), even if blood pressure was better controlled than before the procedure with the same amount of tablets (Fig. 3).

Conclusion
Although our population was quite small, we demonstrated the advantages of renal artery revascularization in atherosclerotic renovascular disease, as demonstrated by kidney function and blood pressure control. Our results contrast the larger studies considered, that found no relevant clinical benefit on renal function and incidence of major adverse cardiovascular and renal events by comparing patients treated with medical therapy alone or with medical therapy plus angioplasty. The different conclusions are probably due to our strict adhesion to the endovascular treatment indications, which consider the revascularization as the optimal strategy for a well-defined population.