Quantitative angiographic anatomy of the renal arteries and adjacent aorta in the swine for preclinical studies of intravascular catheterization devices

Abstract

Swine are the most common animal model in preclinical studies of cardiovascular devices. Because of the recent trend for development of new devices for percutaneous catheterization, especially for the renal arteries (RAs), we examined the quantitative anatomical dimensions of the RAs and adjacent aorta in swine. Angiographic images were analyzed in 66 female Yorkshire/Landrace crossbred swine. The diameter of both the right and left main RA was 5.4 ± 0.6 mm. The length of the right main RA was significantly longer than that of the left (29.8 ± 7.5 mm vs. 20.6 ± 5.4 mm, respectively; P<0.001). The diameter of both the right and left branch RA with diameters ≥3 mm (the target vessel diameter of recently developed devices) was 3.8 ± 0.5 mm. The right branch RA was significantly longer than that of the left (18.9 ± 7.8 mm vs. 16.4 ± 7.4 mm, respectively; P<0.05). The branching angle of the right RA from the aorta was significantly smaller than that of the left (91 ± 12° vs. 103 ± 15°, respectively; P<0.001). The diameters of the suprarenal and infrarenal aorta were 10.6 ± 1.1 mm and 9.7 ± 0.9 mm, respectively. In conclusion, because of their similar dimensions to human, swine are an appropriate animal model for assessing the safety of, and determining optimal design of, catheter devices for RAs in simulated clinical use. However, there were species differences in the branching angle and adjacent aorta diameter, suggesting that swine models alone are inadequate to assess the delivery performance of catheter devices for RAs.

Keywords: angiography; aorta; percutaneous catheterization; renal artery; swine.

Fig. 1.

Illustration of measured vasculatures in angiographic images. (A) The right and the left branching angles of renal arteries (RAs) from the aorta were measured. The diameters of the suprarenal and the infrarenal aorta were measured at the superior and inferior positions of the RAs, respectively. (B) The diameters and lengths of the RAs were measured. The main RA was defined as a single arterial segment from the renal ostium to the first bifurcation. The branch RAs were defined as all arterial segments at the post-bifurcation. Among the branch RAs, the segments that had a diameter ≥3 mm were measured. If the measured diameter was <3 mm, the values were excluded from data analysis. Rt., right; Lt., left.

Fig. 2.

Box plots of the diameter (A) and the length (B) of the RAs. Data are mean ± SD. P-values are shown in each plot.

Fig. 3.

Scatter plots between body weight and dimensions of the main RA. The dimension parameters included the diameters of the right (A) and left (B) main RAs, and the lengths of the right (C) and left (D) main RAs. Pearson’s correlation coefficients (r) and P-values are shown in each plot.

Fig. 4.

Scatter plots between the body weight and the dimensions of the branch RAs with a diameter of ≥3 mm. The dimension parameters included the diameters of the right (A) and the left (B) branch RAs, and the lengths of the right (C) and the left (D) branch RAs. Pearson’s correlation coefficients (r) and P-values are shown in each plot.

Fig. 5.

Box plot of the branching angles from the aorta of the right and the left RAs. Data are mean ± SD. P-values are shown in each plot.

Fig. 6.

Box plot of the diameters of the suprarenal and infrarenal aortas. Data are mean ± SD.

Fig. 7.

Comparison of anatomical dimensions between swine and published human data. Each dot and error bar represent mean and SD, respectively. Data are mean ± SD. P-values are shown in each plot. (A) The diameter of the main RA. (B) The length of the main RA. (C) The branching angle of the RA from the aorta. (D) The diameters of the suprarenal and the infrarenal aortas.