Catheter-based therapy for atherosclerotic renal artery stenosis

Catheter-based therapy for symptomatic (hypertension, ischemic nephropathy, or cardiac destabilization, ie, flash pulmonary edema syndromes), hemodynamically significant, atherosclerotic RAS has become the preferred method of revascularization. The discordance between the high (>95%) procedural success and moderate (60% to 70%) clinical response obtained in patients with renal artery stenosis and hypertension probably is due to poor patient selection related to the very difficult process of angiographically assessing the severity of an aorto-ostial renal artery lesion. Preliminary data suggest that the use of physiological lesion assessment (renal FFR) and/or biomarkers (BNP) can enhance lesion selection and result in improved clinical response rates.40,46 Further studies are needed to establish their clinical role. Data from a single randomized trial and 2 meta-analyses comparing stent placement with balloon angioplasty for atherosclerotic RAS demonstrate overall superiority for stent therapy. The conventional wisdom of using an elevated RI to exclude patients as candidates for revascularization and the argument against treating unilateral RAS to improve renal function have been challenged with data from uncontrolled, nonrandomized clinical trials. The need has become clear to prospectively and objectively evaluate these criteria. Finally, the development of new technologies to further improve the safety and efficacy of renal intervention are on the horizon. The feasibility and safety of embolic protection have been demonstrated by several groups, although trials to determine their efficacy in preserving renal function have not been done. The current restenosis rates are acceptable (<20%), with excellent long-term secondary patency rates (≥80%), but there is room for improvement. Given the dependence on acute gain and late loss, it would appear that there is a role in the renal arteries for drug-eluting stents.86. © 2006 American Heart Association, Inc.