MDCT Angiography of the Renal Arteries in Patients with Atherosclerotic Renal Artery Stenosis: Implications for Renal Artery Stenting with Distal Protection

Abstract

Use of distal protection in renal artery stenting entails overcoming challenges unique to renal artery anatomy. We used 3D image reconstruction to review high-spatial-resolution MDCT angiographic data to better characterize the anatomy of stenotic renal arteries. A total of 218 abdominal MDCT angiograms from a single tertiary care referral center were reviewed. The subjects were 108 patients who had 127 arteries with more than 50% ostial atherosclerotic renal artery stenosis. Vessel analysis software was used to measure renal artery length, cross-sectional area, and maximum diameter. Differences between mean values for women and men and for left and right renal arteries were measured with a two-tailed Student's t test. Significant differences for men and women were found in average maximum cross-sectional area distal to the point of stenosis (0.3 +/- 0.19 vs 0.23 +/- 0.09 cm2, p = 0.006) and the corresponding maximum diameter (6.9 +/- 1.7 vs 6.1 +/- 1.1 cm2, p = 0.003). Average lengths of the main renal artery did not differ significantly for men and women. Differences for the left and right main renal arteries were found in minimum area (i.e., area of maximum stenosis, 0.08 +/- 0.04 vs 0.06 +/- 0.03 cm2, p = 0.03), area proximal to the bifurcation (0.26 +/- 0.11 cm2 vs 0.23 +/- 0.07 cm2, p = 0.02), and length (38.5 +/- 12.6 vs 48.7 +/- 16.2 mm, p = 0.0002). Significant anatomic differences exist between the left and right renal arteries, between the renal arteries in men and those in women, and from one person to the next. Many of these differences are relevant to the design and use of distal protection devices in stenting of the renal arteries.