STABLE Data Published for Cook's Zenith TEVAR System

March 5, 2012—Data from the STABLE trial were published by Joseph V. Lombardi, MD, et al in the Journal of Vascular Surgery (2012;55:629–640). STABLE is evaluating the safety and effectiveness of the Zenith dissection system (Cook Medical, Bloomington, IN), a composite thoracic endovascular aneurysm repair (TEVAR) system, for the treatment of patients with complicated type B aortic dissection.

As detailed in the Journal of Vascular Surgery, in this prospective, single-arm, multicenter study, patients with complicated type B aortic dissection were treated with the Zenith endovascular system, which consists of a proximal TX2 thoracic stent graft and distal bare-metal dissection stent.

Indications for enrollment were branch vessel malperfusion, impending rupture, aortic diameter ≥ 40 mm, rapid aortic expansion, and persistent pain or hypertension despite maximum medical therapy. One-year follow-up results, including clinical and radiographic (computed tomography and x-ray) evaluation, were available for this report.

Ten centers enrolled 40 patients (70% men; mean age 58 years old) between December 2007 and August 2009. The onset of symptoms was acute (≤ 14 days) in 24 patients (60%), subacute (15–30 days) in six patients (15%), and chronic (31–90 days) in 10 patients (25%); the overall mean time from symptom onset to treatment was 20 days (range, 0–78 days).

A majority of patients (77.5%; 31 of 40 patients) presented with impending aortic rupture (indicated by periaortic effusion/hematoma) or branch vessel malperfusion. Seven combinations of stent grafts and dissection stents were used, and all devices were successfully deployed and patent.

The investigators reported that the 30-day mortality rate was 5% (2 of 40); two deaths occurred after 30 days, leading to a 1-year survival rate of 90%. Two deaths, occurring at 11 and 81 days postprocedure, respectively, were secondary to aortic rupture. Morbidity occurring within 30 days included stroke (7.5%), transient ischemic attack (2.5%), paraplegia (2.5%), retrograde progression of dissection (5%), and renal failure (12.5%). Additional morbidity after 30 days included one case of retrograde progression of dissection and one case of renal failure. None of the patients with renal failure became dialysis-dependent. Four patients (10%) underwent secondary interventions within 1 year.

Favorable aortic remodeling was observed during the course of follow-up, indicated by an increase in the true lumen size and a concomitant decrease in the false lumen size along the dissected aorta, with a completely thrombosed thoracic false lumen observed in 31% of patients at 12 months as compared to 0% at baseline.

The investigators concluded that initial data with a composite TEVAR construct have demonstrated favorable clinical and anatomic results; however, continued enrollment and long-term data are needed to assess the overall effectiveness of this treatment strategy.