Outcomes With Aptus AAA Repair Systems Evaluated in Pivotal Study

August 7, 2014—An investigational device exemption (IDE) study designed to assess outcomes of abdominal aortic aneurysm (AAA) repair with the Aptus endograft and EndoAnchors (Aptus Endosystems) was published by Manish Mehta, MD, et al in the Journal of Vascular Surgery (2014;60:275–285).

As noted in the Journal of Vascular Surgery, the Aptus endograft is a two-component system. It consists of a multilumen, modular endograft with two docking limbs (Aptus endograft system) and the Heli-FX aortic securement system, which is composed of an electronically controlled applier (Heli-FX Applier) with helical EndoAnchors provided in a cassette and a deflectable sheath (Heli-FX Guide) designed for delivery of the applier to the target location for EndoAnchor implantation.

The investigators advised that this prospective, multicenter, single-arm IDE trial was conducted at 25 sites in the United States and enrolled 155 patients (mean age, 73 ± 8 years; men, 93.5%; mean AAA diameter, 53.6 ± 7.9 mm). The main eligibility criteria included proximal neck length of ≥ 12 mm, diameter of 19 to 29 mm, and infrarenal angulation of ≤ 60°.

The primary safety endpoint was freedom from major adverse events at 30 days, and the primary effectiveness endpoint was successful aneurysm treatment at 12 months. Thrombus-related events (TRE) were defined as limb occlusion or thromboembolism from the endograft. Patients were observed for a median of 4.2 years, with imaging endpoints analyzed by a core laboratory and adverse events adjudicated by a clinical events committee.

Among 155 enrolled patients, 153 (98.7%) underwent successful implantation of the Aptus endograft and a median of five EndoAnchors; two patients were converted to open surgical repair during the initial procedure.

The investigators reported that overall, the primary safety and effectiveness endpoints were met in 98.1% and 97.4% of the patients, respectively. Aneurysm-related mortality was 0.6%, with one postdischarge cardiac death at 18 days after implantation. There were no AAA ruptures. There were no fractures of stents or EndoAnchors. There was one type I endoleak and one type III endoleak. Stent graft migration was noted in five patients, none associated with sac enlargement, type I endoleak, or EndoAnchor dislocation from the endograft. AAA sac shrinkage of ≥ 5 mm at 1, 2, and 3 years was observed in 60.3%, 72.9%, and 81.7%, respectively.

There were 61 patients (39.4%) who experienced 113 TRE, associated with 80 reinterventions (in 58 patients) unassociated with limb loss or death. A root cause analysis of TRE identified small, out-of-specification docking limbs with graft infolding and high local shear, resulting in thrombus formation within the endograft with subsequent distal embolization in some cases.

The investigators concluded that early results of the Aptus endograft trial met its safety and effectiveness endpoints; however, a high rate of TRE was observed because of manufacturing discrepancies. The findings confirm a low rate of type I and type III endoleaks, migration, and non-TRE reintervention with a high rate of aneurysm sac regression during midterm follow-up, stated the investigators in Journal of Vascular Surgery.