Renal Artery Stenosis

A s the prevalence and treatment of renal artery stenosis become more common, newer challenges arise. This case illustrates three such challenges: (1) the variable anatomy of the perirenal aorta, (2) the etiology and hemodynamic effect of renal artery lesions, and (3) the presence of restenosis. Renal artery angioplasty and stenting via the retrograde femoral approach can sometimes be difficult due to the inferior and posterior course of the proximal renal artery segment. In some instances, the acute angulation of the renal artery precludes balloon and stent delivery. Some operators, therefore, prefer the brachial approach to allow for a more coaxial alignment. The brachial approach, however, leads to a greater incidence of vascular access site complications.1 Furthermore, the manipulation of guiding catheters in an atherosclerotic aorta can cause serious complications from cholesterol emboli.2-4 These technical difficulties with catheter manipulation can be further exaggerated by lesion location or the presence of restenosis. Atherosclerosis accounts for approximately 90% of cases of stenosis within the renal arterial bed. Atherosclerotic lesions usually involve the origin and proximal third of the main renal artery and also the perirenal aorta.5 Fibromuscular dysplasia (FMD) accounts for <10% of cases of renal artery stenosis, and usually involves the distal two-thirds of the main renal artery or its branches.5,6 Additionally, with widespread use of endovascular stenting, the issue of in-stent restenosis is more commonly encountered. This article describes a technically difficult case of renal artery angioplasty, or percutaneous transluminal angioplasty (PTA). The renal artery assumed an inferior course, arising with an acutely angulated origin from the aorta. Due to concern about the brachial approach in a small-sized patient, cannulation of the artery was performed via a retrograde femoral approach. The proximal portion of the vessel had severe restenosis of a previously stented atherosclerotic lesion. In addition, the distal portion of the main renal artery demonstrated classic FMD with associated high-grade stenosis. All of these factors combined make manipulation of the guiding catheter, wire, and balloon catheter very challenging.