EVAR Outcomes with Anatomical Fixation

OBJECTIVES: Endovascular abdominal aortic aneurysm repair (AAA) has been widely adopted as a less invasive alternative to open surgical repair. Initial modular devices were designed to mimic surgical grafts, with a short body fixed at the level of the renal arteries and long limb components placed distally. To decrease the risk of component separation associated with modular devices relying on positive fixation (hooks, barbs, suprarenal stents), the Endologix Powerlink unibody device was developed with a fully supported long main body and shorter limbs. Following initial clinical experience, physician use of the device with physiologically sound fixation at the aortoiliac bifurcation and concomitant neck and limb seal was thought to potentially mitigate distal migration. We report the controlled trial results of this device implant algorithm.
METHODS: Between 2000 and 2007, 157 eligible patients presenting with AAA were enrolled in FDA-approved, prospective, nonrandomized, multicenter trials. Each patient received an anatomically-fixed Powerlink infrarenal bifurcated stent graft, and neck or iliac extensions as needed to achieve seal. Procedural outcomes and mortality, major adverse events, and stent graft fixation performance were assessed at early and late timepoints.
RESULTS: Patients presented at a mean age of 72±9.1 years with mean aneurysm sac diameter of 5.6cm. Successful device delivery and deployment with full aneurysm exclusion was achieved in all patients. Within one year and to current follow-up to five years, no conversions, ruptures, or migrations occurred. Two patients underwent successful intervention for limb occlusion. Identified endoleaks were resolved in 12 patients (six type II; five type I proximal; three type I distal). Core lab analysis determined a stable or shrinking aneurysm at 1 and 5 years in 95% and 93% of patients, respectively, with no stent or graft failures or type III/IV endoleaks. One-year all cause mortality is 7.0%; freedom from aneurysm-related mortality is 100% through current follow-up.
CONCLUSIONS: Anatomic fixation of the Powerlink unibody bifurcated stent graft increases sealzone length to safely and effectively treat AAA disease without distal migration.