The Zenith AAA endovascular graft for abdominal aortic aneurysms: clinical update

The aim of this study was to provide an update regarding the US clinical trial assessing the performance of the Zenith AAA Endovascular Graft in the treatment of abdominal aortic aneurysms.

A prospective, nonrandomized, concurrent control-based study design was used to contrast conventional repair of infrarenal aneurysms with endovascular repair in patients that would otherwise be candidates for open surgical procedures. Additional study arms allow high-physiologic-risk patients and roll-in patients to be treated using the same endovascular device in a registry format. Patients were evaluated clinically and radiographically computed tomography (CT) and abdominal radiographs) before any intervention, at hospital discharge, 30 days, 6 months, 12 months, and yearly thereafter. Data were analyzed with the intent of assessing acute and chronic morbidity and mortality, radiographic parameters indicative of successful aneurysm repair, and device integrity.

A total of 352 patients were treated with the Zenith graft (one patient did not receive an implant in the standard-risk group), and 80 patients underwent conventional surgical repair. Two hundred patients were enrolled in the standard-risk group, 100 in the high-risk group, and 52 underwent endovascular repair as roll-in patients. All cause mortality, aneurysm-related deaths, and ruptures were statistically identical between the groups. Procedural morbidity was significantly lower for patients treated with endovascular grafts with respect to cardiac, pulmonary, renal, and vascular complications. Secondary interventions were more commonly required in the endovascular group. The endoleak rate was 4.9% at 12 months in the standard-risk endovascular group. There was one rupture in the high-risk subset of patients and 3 elective conversions. A total of 1.6% of the endovascular patients were noted to have a barb separation without evidence of significant migration or clinical events. No other device integrity issues were observed.

The safety of the Zenith endovascular graft was superior to conventional management with respect to morbidity and clinical utility. The short-term device efficacy was satisfactory; however, longer-term follow-up will be necessary to establish the duration of this observation.