Comparison of Early Sac Shrinkage with Third-Generation Stent Grafts for Endovascular Aneurysm Repair

Purpose To compare the effects of the currently most-used third-generation stent grafts on early aneurysm sac shrinkage, a proposed marker of successful endovascular aneurysm repair (EVAR). Materials and Methods EVARs performed from 2009 to 2013 at 2 institutions were retrospectively analyzed. Patients treated with a Zenith, EXCLUDER, or Endurant device who completed imaging studies before EVAR and at 1, 6, 12, and 24 months afterward were included. Sac shrinkage was compared by volumetry. Results Among 296 EVAR procedures, 47 were excluded for the use of different stent grafts and 87 for loss to follow-up or missing required imaging study, leaving 162 EVAR procedures (69 Zenith, 54 EXCLUDER, and 39 Endurant devices) for analysis. Mixed-effects model analysis revealed that the use of a Zenith device resulted in significantly greater shrinkage compared with EXCLUDER and Endurant devices (both P < .001). The differences were statistically significant from 1 month after EVAR (average sac shrinkage at 1 mo for Zenith, EXCLUDER, and Endurant devices of 95.3%, 100.3%, and 102.6%, respectively), indicating an early shrinkage advantage for Zenith devices. In addition, multivariate analysis revealed Zenith device use to be a sole beneficial factor for sac shrinkage at 24 months after EVAR (odds ratio, 2.881; 95% confidence interval, 1.331–6.235; P = .007). Repeat intervention rates (all for treatment of type II endoleaks) for Zenith, EXCLUDER, and Endurant devices were 2.9% (2 of 69), 1.9% (1 of 54), and 2.6% (1 of 39), respectively. Conclusions Zenith device use was associated with significantly better early sac shrinkage. In view of the limited follow-up period, whether these differences lead to improved clinical outcomes remains unclear.