Pivotal results for the Medtronic Valiant Thoracic Stent Graft System in the VALOR II trial.

OBJECTIVE

We report 30-day and 12-month results of endovascular treatment with the Valiant Thoracic Stent Graft System (Medtronic Vascular, Santa Rosa, Calif) in patients with descending thoracic aortic aneurysms of degenerative etiology. The Valiant stent graft is an evolution of the Talent thoracic stent graft (Medtronic Vascular).

METHODS

The VALOR II (Evaluation of the Clinical Performance of the Valiant Thoracic Stent Graft System in the Treatment of Descending Thoracic Aneurysms of Degenerative Etiology in Subjects Who Are Candidates for Endovascular Repair) was a prospective, nonrandomized, pivotal trial conducted at 24 U.S. sites with enrollment between December 2006 and September 2009. Standard follow-up examinations, including physical examination, computed tomography, and chest radiography, were at 1, 6, and 12 months, and annually through 5 years. VALOR II outcomes were compared with those from the pivotal VALOR (Evaluation of the Medtronic Vascular Talent Thoracic Stent Graft System for the Treatment of Thoracic Aortic Aneurysms) trial of the Talent stent graft, which enrolled 195 patients with similar enrollment criteria.

RESULTS

VALOR II enrolled 160 patients. Compared with VALOR patients, VALOR II patients had similar age and sex distribution but higher rates of cardiovascular risk factors and significantly more severe modified Society for Vascular Surgery/American Association for Vascular Surgery risk scores. Stent graft delivery and deployment were successful in 154 patients (96.3%). Outcomes at 30 days in VALOR II were perioperative mortality, 3.1%; major adverse events, 38.1%; paraplegia, 0.6%; paraparesis, 1.9%; and stroke, 2.5%. At 12 months, after the minimum sample size was reached, 151 patients were evaluated: aneurysm-related mortality was 4.0%, stent graft migration was 2.9%, and endoleak was 13.0%. Through 12 months, there were no ruptures, conversions to open surgery, secondary procedures due to endoleak >30 days, or loss of stent graft patency. The Valiant stent graft was statistically noninferior to the Talent stent graft in 12-month all-cause mortality (12.6% vs 16.1%) and exceeded the primary effectiveness goal of 12-month successful aneurysm treatment, defined as absence of aneurysm growth >5 mm and of secondary procedures for type I/III endoleak (97.4% vs 80.0%).

CONCLUSIONS

The VALOR II 12-month results demonstrate that the Medtronic Valiant thoracic stent graft is a safe and effective treatment for patients with descending thoracic aortic aneurysms of degenerative etiology.