New generation of stent-grafts curbs migration

Stent-graft migration in patients with aortic abdominal aneurysms can lead to severe postinterventional complications, including the open surgery they were meant to avoid. The latest generation of these devices can prevent migration, according to a presentation Tuesday.

Dr. Claudia V. Walch and colleagues at the University of Innsbruck in Austria enrolled 64 patients treated for AAA with endovascular repair. Patients underwent follow-up at six, 12, 24, 36, and 48 months, including CT-based migration analysis. The investigators found the longitudinal stability of newer stent-grafts reduced migration compared with first-generation devices.

Researchers assessed the stability of several stent designs: Vanguard (Boston Scientific), Talent (Medtronic), Zenith (William Cook), and Excluder (W.L. Gore). Most migration happened within the first 12 months after intervention. No further substantial migration occurred at 24 or 36 months.

The proximal ends of the stent-grafts showed a mean craniocaudal migration of 5.6 mm for the Vanguard and Talent devices, 2.55 mm for the Excluder, and 2 mm for the Zenith. The distal ends showed a mean craniocaudal migration of 5.6 mm for the Talent device, 3.9 mm for the Vanguard, 2.5 mm for the Excluder, and 2 mm for the Zenith. The bifurcation showed a mean axial migration of 21.6 mm for the Vanguard device, 14 mm for the Talent, 2 mm for the Excluder, and none for the Zenith.

The findings reinforce previous research confirming the benefits and growing popularity of stent-grafting, in many cases for uses beyond prevention.

Italian and Swiss researchers, for instance, had reported earlier this year that endovascular treatment of patients with ruptured AAA was safer and had lower mortality rates than open surgery. Both groups reported high technical success, very low morbidity, and no mortality associated to the stent-graft procedure after a two-year follow-up. The groups presented their findings in March at the European Congress of Radiology.