Impact of Compliance with Anatomical Guidelines of "Bell-Bottom" Iliac Stent Grafts for Ectatic or Aneurysmal Iliac Arteries.

Abstract

To evaluate the impact of compliance with anatomical guidelines on outcomes of endovascular aortic aneurysm repair using "bell-bottom" stent grafts (BBSGs). This is a retrospective review from January 1999 to May 2012 of patients who underwent endovascular infrarenal abdominal aneurysm repair and whose iliac limbs were greater than 18mm in diameter. Computed tomography angiography was utilized for compliance with anatomical guidelines as stated in manufacturer's instructions for use (IFU). The primary outcome observed was iliac limb events. The secondary outcome observed was the need for re-intervention due to BBSG failure. Of the 376 BBSGs,55 (15%) in 27 patients met IFU. Aneurysm exclusion was achieved in all patients.The mean follow-upwas 44 ± 30months. Twenty-eight patients (11%) had 29 iliac limb events (12 type 1b endoleaks, 4 aneurysm sac growth, 4 stenosis/kink, 4 retrograde migrations, 2 component separations, 2 ruptures and 1 limb occlusion); all among patients treated outside of IFU (p < 0.04). The rate of aneurysm sac enlargement was similar between both groups, at 56%, respectively, between those treated within and those treated outside of IFU. On multivariate regression analysis, largercommon iliac artery (CIA)(HR 1.088, 95% CI 1.016-1.166, p = 0.016), greater CIA tortuosity (HR 2.352, 95% CI 1.004-5.509, p = 0.048) and limbs with more than two characteristics that did not meet IFU criteria (HR 3.84, 95% CI 1.15-12.83, p = 0.03) were associated with higher rates of BBSG events and re-interventions. BBSGs effectively seal ectatic CIAs. But rates of iliac limb events and re-interventions are higher among patients who do not meet IFU criteria. The larger CIA diameter, the greater CIA tortuosity and more than two criteria not met by IFU were associated with BBSG failure and re-intervention.