PC4. Comparative Geometric Analysis of Renal Artery Anatomy Before and After Fenestrated or Snorkel/Chimney EVAR

Abstract

Values in mean 6 standard deviation. D, Change from pre-op to post-op; NS, no Positive end-stent angle indicates vessel angulation with respect to the stent end Significant changes from pre-op to post-op (P < .05). Significant difference between LRA and RRA (P < .05). underwent computed tomography angiography before and after F-EVAR (n 1⁄4 21) or Sn-EVAR (n 1⁄4 20), which involved a total of 74 renal artery stents. Renal artery geometry was quantified using three-dimensional modelbased centerline extraction. Stented length was computed from vessel origin to stent end. Branch angle was computed relative to orthogonal configuration with respect to the aorta at vessel origin. End-stent angle was computed relative to distal native renal artery. The radius of curvature was defined by the circumscribed circle at the highest curvature within the proximal portion from the origin to the stent end, and distal portion from the stent end to first renal artery bifurcation. Results: Stented renal artery length, branch angle, end-stent angle, and maximum change in radius of curvature from preoperative to postoperative are presented in the Table. Sn-renals had greater stented length compared with F-renals (P < .02). From preoperative to postoperative, origins of the Sn-renals angled increasingly downward (P < .002), whereas F-renals angled increasingly upward (P < .002). End-stent angle of SnRRA increased from preoperative to postoperative (P < .00001), and Sn-RRA exhibited a greater magnitude change in end-stent angle compared with Sn-LRA (P < .05) and F-RRA (P < .0005). Radius of curvature decreased in distal Sn-RRAs (P < .02). Acute renal failure occurred in 9.8% of patients, and none required dialysis. Renal stent patency was 98.6% at mean follow-up of 13.7 months. Five type IA endoleaks were identified, prompting one secondary procedure. One renal artery reintervention was performed due to an asymptomatic kinked left renal stent. Conclusions: Stented renal arteries were angled more inferiorly after Sn-EVAR and superiorly after F-EVAR due to stent configuration. Sn-EVAR induced significantly greater angle change at the stent end and curvature change distal to the stent compared to F-EVAR due to greater angle change of the Sn-renals, although no difference in patency was noted. Sn-RRA exhibited larger endstent angle change from preoperatively to postoperatively compared to the Sn-LRA, likely because the presence of the IVC on the right side restricts motion of the proximal RRA. The occurrence of the kinked left renal stent is consistent with the proximal right renal artery being more mechanically supported by the IVC. Additional