Secure fixation following EVAR with the Powerlink XL System in wide aortic necks: results of a prospective, multicenter trial.

Purpose: Endovascular stent graft repair of abdominal aortic aneurysms (AAA) with the Endologix Powerlink System (Endologix, Inc, Irvine, Calif) has been shown to be a safe and effective alternative to open surgery in patients having an aortic neck diameter of up to 26 mm. We assessed the safety and effectiveness of AAA repair in patients with wide aortic necks (up to 32 mm in diameter) using the Powerlink XL System.

Methods: Between September 2005 and June 2008, a prospective, multicenter, pivotal US Food and Drug Administration trial of the Powerlink XL System for endovascular aneurysm repair was conducted at 13 centers. Using a sizing algorithm based on computed tomography scan (CT)-based measurements, a total of 78 patients (N = 60 [pivotal trial]; N = 18 [continued access]) presenting with AAA and an infrarenal aortic neck up to 32 mm in diameter received a bifurcated stent graft via anatomical fixation at the aortoiliac bifurcation and proximal sealing with a Powerlink XL infrarenal proximal extension stent graft. Postoperatively, results were assessed with contrast-enhanced CT scans and abdominal x-rays at one, six, and 12 months, with continued annual follow-up to five years.

Results: Predominantly male (91%), patients presented at a mean age of 73 +/- 8.6 years with mean maximum aortic neck and AAA diameters of 31 +/- 1.9 mm (range, 25 to 32 mm) and 5.7 +/- 1.0 cm (range, 4.3 to 10 cm), respectively. Challenging infrarenal aortic neck anatomy, defined as the presence of severe thrombus and/or reverse taper, was present in 85% of patients. Technical success was achieved in 98.7% of patients, with one patient requiring femoral-femoral bypass intraoperatively. Aneurysm exclusion was achieved in 100% of patients over a mean procedure time of 129 +/- 66 minutes. Patients were discharged at a mean of 2.2 days postoperatively. At the one-month CT scan, the independent core lab identified a Type II endoleak in 13 patients, distal Type I and Type II endoleak in one patient, and unknown endoleak in three patients. At 30 days, there were no deaths, conversions, ruptures, or migrations. Through one year follow-up, Type II endoleak predominated (9/10 patients with endoleak), with one proximal Type I and no Type III, IV, or unknown endoleak; no conversions, ruptures, or migrations have been observed. The one-year all-cause mortality rate was 6.4%, with 100% freedom from aneurysm-related mortality. Secondary procedures were performed within one year in five patients (6.4%) for treatment of proximal Type I endoleak (n = 2), proximal Type I/Type II endoleak (n = 1), and distal Type I endoleak (n = 2). Reduced or stable aneurysm sac diameter at one year is observed in 96% of patients.

Conclusions: The combination of an anatomically-fixed Powerlink bifurcated stent graft and a Powerlink XL infrarenal proximal extension appears safe and effectively excludes aneurysms in patients with wide aortic necks. These results suggest that fixation at the aortic bifurcation can provide secure fixation for patients with large diameter diseased proximal aortic necks.