Medtronic's Endurant Stent Graft Studied for EVAR of Infrarenal AAAs

May 1, 2014—Four-year data from an evaluation of the Endurant stent graft (Medtronic, Inc.) for endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs) were published by Herman J.A. Zandvoort, MD, et al in the Journal of Vascular Surgery.

As summarized in the Journal of Vascular Surgery, the investigators prospectively collected all clinical data, including detailed anatomic information of the first 100 consecutive patients treated with the Endurant stent graft for an infrarenal AAA at three Dutch high-volume hospitals. CT angiography was routinely performed before the procedure, ≤ 1 month, and at 1 year after EVAR. Thereafter, the imaging modality during yearly follow-up was individualized (duplex ultrasound imaging or CT angiography). 

Patients were classified as within or outside the instructions for use (IFU) for analysis. Study endpoints were primary clinical success, overall and AAA-related mortality, and sac morphology changes and endoleak during follow-up. Estimates were obtained using Kaplan-Meier plots.

The study included 100 consecutive patients (88 men) with a median age of 74 years (interquartile range [IQR], 67–79 years) and a median AAA diameter of 58 mm (IQR, 55–65 mm) between December 2007 and March 2009. Twenty patients (20%) were treated outside the IFU (18 outside proximal neck IFU, one outside iliac IFU, and one outside both IFUs). Median follow-up was 48 months (IQR, 36–53 months), and no patients were lost. 

The investigators reported that one contained rupture was observed after 1.5 months due to graft infection. No patients had graft migration. Two type IA endoleaks, five type IB endoleaks, and 15 type II endoleaks were found. Primary clinical success was 97%, 90%, 84%, and 77% at 1, 2, 3, and 4 years, respectively. Primary clinical success was comparable for patients treated within or outside the IFU (P = .2), although both patients outside the iliac IFU needed a secondary iliac intervention. Over time, the maximum aneurysm diameter decreased ≥ 5 mm, remained stable, or increased ≥ 5 mm in 58%, 32%, and 10% of the patients, respectively. All-cause mortality was 20% at 4 years, with 3% AAA-related mortality.

The investigators concluded that this 4-year follow-up data for the Endurant stent graft in AAA treatment show that its use offers a low AAA-related mortality rate with adequate prevention of rupture or aneurysm growth. Although patients with very challenging anatomy were treated in this series, primary clinical success rates were comparable for patients treated within and outside the IFU. These results may aid in improving outcomes in the future, noted the investigators in the Journal of Vascular Surgery.