Is there an indication for embolic protection in renal artery intervention?

The role of endovascular treatment of atherosclerotic renal artery disease is uncertain, particularly after the publication of the Angioplasty and Stenting for Renal Artery Lesions trial and other randomized trials. These trials have shown that nonselective treatment of patients with renal artery stenosis does not result in a benefit when compared with best medical therapy. However, all trials have identified a subgroup of patients who do respond favorably to revascularization. In particular, patients with a degree of chronic renal insufficiency, critical renal artery stenosis, and a recent decline in renal function are likely to respond positively to revascularization. Endovascular treatment of renal artery stenosis must be performed safely, particularly in the high-risk patient group with background chronic renal insufficiency. Atheroembolization occurs during renal artery revascularization, as demonstrated by ex vivo studies and the high embolic yield obtained in published series of protected renal artery revascularization. The evidence supporting embolic protection includes single-center series wherein excellent results for renal function preservation have been reported. One small, randomized, controlled trial demonstrated a significant benefit if both embolic protection and abciximab were used. There are unique demands on an embolic protection device in the renal artery circulation and a dedicated device has not been developed. Both distal filters and occlusion balloons have been successfully used. Both devices can normally be primarily passed through the stenosis, allowing the remainder of the procedure to be protected. Filters have the advantage of maintaining renal perfusion throughout the procedure. Distal occlusion balloons can capture embolic particles of all sizes although the clinical advantage is uncertain.