The Zenith AAA endovascular graft.
The Zenith endovascular graft is the culmination of a worldwide collaboration of experts whose experience and developments were compiled, resulting in an endovascular prosthesis designed to treat infrarenal abdominal aortic aneurysms. The device is made of stainless steel, self-expanding Z-stents and polyester fabric. It has an uncovered stent with barbs (for fixation) that extend into the suprarenal aorta and is modular in design and allows for disparity in the length and diameter of the iliac arteries that are incorporated into the repair. A prospective study contrasting endovascular and open surgical patients was completed in 2002 and resulted in US Food and Drug Administration approval of the device for commercial sale within the USA. Although long-term data from the trial are still being evaluated, the worldwide experience with this device and its predicate devices has allowed for certain conclusions to be made with respect to performance expectations and aneurysm sac behavior. The periprocedural mortality in healthy patients with anatomy meeting the device instructions for use should be under 2%. The expected risk of endoleak (mostly Type II) was 7.4% at 12 months and 5.4% at 24 months. Migration (based on the reporting standards for endovascular aneurysm repair recommended by the vascular surgical societies, published in the Journal of Vascular Surgery in 2001) was not seen in any patients over 12 months. The majority of the aneurysms shrink at 1 and 2 years, and any patient exhibiting aneurysm growth had a detectable cause and required treatment. Coupled with European and Australian data, including several device explants, the device integrity issues are limited to barb separation (which has about a 2% incidence and appears incidental in the US trial) and suprarenal stent detachment (six cases detected worldwide). In order to address the latter problem, a design alteration was implemented with a double suture attachment, significantly increasing the tensile strength of the device. No separations have been noted since the change instituted at the conclusion of the US trial.
Kaviani
Amir
A
The Cleveland Clinic Foundation, Department of Vascular Surgery, Cleveland, Ohio 44195, USA.
Greenberg
Roy K
RK
D017130:Angioplasty; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D001807:Blood Vessel Prosthesis / Q000009:adverse effects; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000379:methods; D004867:Equipment Design; D004869:Equipment Safety; D006801:Humans; D011183:Postoperative Complications; D012307:Risk Factors; D015607:Stents