Prospective multicenter clinical trial (STABLE) on the endovascular treatment of complicated type B aortic dissection using a composite device design.

OBJECTIVE: This study evaluates the safety and effectiveness of a unique composite thoracic endovascular aneurysm repair (TEVAR) construct (proximal stent graft and distal bare metal stent) for the treatment of patients with complicated type B aortic dissection (cTBAD).

METHODS: In this prospective, single-arm, multicenter study, patients with cTBAD were treated with an endovascular system consisting of proximal TX2 thoracic stent grafts and distal bare metal dissection stents (Zenith Dissection Endovascular System; Cook Medical, Bloomington, Ind). 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 (computerized tomography [CT] and X-ray) evaluation, were available for this report.

RESULTS: 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 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 completely thrombosed thoracic false lumen observed in 31% of patients at 12 months as compared to 0% at baseline.

CONCLUSIONS: Initial data with a composite TEVAR construct have demonstrated favorable clinical and anatomic results. Continued enrollment and long-term data are needed to assess the overall effectiveness of this treatment strategy.