Ischemic nephropathy: proteinuria and renal resistance index could suggest if revascularization is recommended

Background: The aim of endovascular therapy in renal artery stenosis (RAS) is to preserve renal function and have a better hypertension control. The purpose of our study was to determine which biochemical and instrumental parameters could predict a better renal outcome in patients with RAS treated with percutaneous transluminal angioplasty and stenting (RPTAS). Methods: We performed an observational study based on 40 patients with RAS who met the following criteria before revascularization: urinary protein excretion of over 250 mg/24 h, normal renal function, and/or mild-moderate renal insufficiency (I, II, and III levels of classification of chronic kidney disease, K-DOQI). Results: Assessment at 12 months after RPTAS showed in 20 patients (Group A) that proteinuria serum creatinine (Scr) and creatinine clearance (CrCl) significantly worsened from the baseline; whereas in 20 patients (Group B) proteinuria remained unchanged and the renal function improved after the procedure. Conclusions: In our study, the decline of renal function after RPTAS is associated with an elevated renal resistance index (RI) in both kidneys (0.83 +/- 0.2) and preexisting proteinuria.