Critical review of indications for renal artery stenting: do randomized trials give the answer?

Significant renal artery stenosis (RAS) is a well accepted cause of deterioration of arterial hypertension and of renal insufficiency. Just recently, more interest has been focused on the impact of RAS on structural heart disease and patient survival. Technical improvements of diagnostic and interventional endovascular tools have lead to a more widespread use of endoluminal renal artery revascularization and extension of the indications for this type of therapy during the past 2 decades. Since the first renal artery angioplasties performed by Felix Mahler and Andreas Grüntzig, numerous single centre studies have reported the beneficial effect of percutaneous transluminal renal angioplasty, and since the early 1990's stenting of renal artery stenosis caused either by atherosclerosis or fibromuscular dysplasia. However, none of the so far published or presented randomized controlled trials (RCT) could prove a beneficial outcome of RAS revascularization compared with medical management. As a result of these negative trials including the recently presented ASTRAL trial, referrals to endovascular renal artery revascularization went down and moreover, reimbursement of these procedures became a matter of debate. This article summarizes the background and the limitations of the so far published and still ongoing controlled trials. Moreover, we discuss why well-designed registries might give important insight on the impact of endovascular revascularization of hemodynamically relevant atherosclerotic RAS.