[Non-surgical treatments of renal artery stenoses]

Management of patients with renal artery stenoses is aimed at normalizing or reducing blood pressure and correcting or preventing reduced glomerular filtration. The results of renal revascularization have been documented mainly in retrospective, uncontrolled reports in which blood pressure improvement was overestimated due to the placebo effect and optimization of drug treatment, the latter being frequently required despite adequate revascularization. In an overview of 10 series reporting blood pressure outcome following percutaneous angioplasty, cure rates were 50% in patients with fibrodysplastic stenosis but only 19% in those with atherosclerotic stenosis. The literature on revascularization of atherosclerotic stenosis with progressive renal failure shows that 55% of patients have improved renal function following surgery and 41% following angioplasty. Mortality is 6 and 5% respectively. The first controlled trials comparing revascularization to medical treatment in renal artery stenosis have recently been published. In a prospective randomized trial, Weibull et al. compared percutaneous angioplasty and surgery in 58 patients with unilateral atherosclerotic stenosis. Although 17% of the patients initially treated with angioplasty required subsequent surgery, blood pressure, renal function and renal artery patency rate did not differ between angioplasty and surgery 24 months after treatment. A Scottish group reported a prospective randomized trial of percutaneous angioplasty vs. medical therapy in patients with bilateral or unilateral atherosclerotic stenosis. In the bilateral group (n = 28), the drop in systolic pressure was significantly larger following angioplasty than following medical therapy, but diastolic pressure and creatinine did not differ after 24 months. In the unilateral group (n = 27), there were no differences in blood pressure or creatinine levels following angioplasty or medical therapy. Several randomized trials comparing angioplasty and conservative treatment or angioplasty and stent placement in patients with renal artery stenosis and normal or reduced renal function are currently underway. They should provide additional information regarding the risk/benefit ratio of these procedures.