[Results of renal artery stenting in patients with stage III-IV ischemic nephropathy]

After the ASTRAL (2009) and CORAL (2014) studies, many questions regarding renal artery stenting remained unanswered. First of all, it concerns defining the groups of patients in whom a good clinical effect of renal revascularization can be anticipated.

The purpose of this study was to assess the effect of renal artery stenting on the course of stage III-IV chronic ischemic kidney disease in patients with significant renal artery stenosis (>70%).

Our single-center, retrospective-prospective study enrolled a total of 158 patients with a hemodynamically significant renal artery stenosis and confirmed stage III-IV chronic kidney disease. It was determined that progressing atherosclerotic renal artery stenosis was the main cause of the development of chronic kidney disease, since all other possible causes were ruled out. All patients were treated by a nephrologist but chronic kidney disease was progressing. These 158 patients besides medicamentous therapy were subjected to an operation in the scope of renal artery angioplasty and stenting. The results of treatment were evaluated at discharge from hospital (up to 7 days), 1 month after surgery and then after 1, 3 and 5 years. The endpoints included the change in the stage of the disease, stabilization of the course of chronic kidney disease, and transfer to renal replacement therapy (programmed hemodialysis).

Prior to renal artery stenting, the average glomerular filtration rate in our patients was 47.5±10.4 ml/min/1.73 m2, amounting to 61.3±20.2 ml/min/1.73 m2, 62.7±20.1 ml/min/1.73 m2, and 55.2±19.4 ml/min/1.73 m2, at discharge, after 1 year, and after 3 years, respectively. The difference turned out to be statistically significant (p<0.001). 'Transformation' of the grades of chronic kidney disease before and after surgery was determined. We managed to improve or stabilize the course of ischemic nephropathy in 91.9% patients within a period of up to 12 months and in 89.7% - more than 1 year of follow-up. We succeeded to avoid switching to renal replacement therapy in 11 patients with the glomerular filtration rate less than 30 ml/min/1.73 m2. Prognostically meaningful factors influencing the outcome after renal artery stenting were found to be as follows: diabetes mellitus (HR 0.234; p=0.003), renal arcuate arteries resistive index less than 0.8 (HR 0.274), and an initially pronounced decrease in the glomerular filtration rate (C4 chronic kidney disease) (HR 0.219; p=0.006). A clear correlation was revealed between persistence of the clinical effect and the duration of chronic kidney disease prior to renal revascularization.

The presence of a significant renal artery stenosis in a patient with stage III-IV chronic ischemic kidney disease should be considered as an indication for renal revascularization. Such strategy results in improvement of the renal function for a period of not less than 3 years.