Pulsatility in the Iliac Artery Is Significant at Several Levels: Implications for EVAR

Abstract

To evaluate the pulsatility of the iliac arteries and compare their distension at several levels that might influence preoperative stent-graft sizing and the long-term durability of stent-graft sealing and fixation. Preoperative dynamic computed tomographic angiography (CTA) scans of 30 patients (24 men; median age 75 years, range 60-85) with an abdominal aortic aneurysm and patent iliac arteries were included. The CTAs consisted of 8 images per heartbeat. Bilateral diameter and area changes per heartbeat were measured semi-automatically in the common iliac artery (CIA) at 3 levels: (A) 0.5 cm after the aortic bifurcation, (B) in the middle of the CIA, and (C) 0.5 cm proximal to the iliac bifurcation. Pulsatility was defined as the largest difference in area and average diameter change over 180 axes per heartbeat. Pulsatility at the 3 levels was compared, and the intraobserver variability of the method was calculated according to Bland and Altman. The mean area increases in the CIAs at levels A, B, and C were 12.5% (16.3 mm²), 11.2% (13.6 mm²), and 9.6% (12.6 mm²), respectively, and the mean iliac diameter increases were 9.2% (1.1 mm), 8.5% (1.0 mm), and 8.1% (1.0 mm). The iliac distension was statistically significant at all levels. The iliac distension at level A was statistically significantly larger than the distension at level C. The intraobserver variability was 13.3 mm² for area and 0.6 mm for diameter measurements. The pulsatility in the iliac arteries is statistically significant at several levels relevant to endovascular aneurysm repair. The distension of the iliac artery possibly decreases more distally, which might encourage the extension of stent-grafts to the internal iliac artery.