The data, results of five-year patient follow-up, were presented on Friday, October 2, 2015 by Mark F. Conrad, M.D., Director of Clinical Research, Division of Vascular and Endovascular Surgery and Assistant Program Director, Division of Vascular and Endovascular Surgery for Massachusetts General Hospital, at the 42nd Annual Meeting of the New England Society for Vascular Surgery in Newport, R.I.

"The five-year results from VALOR II provide confidence to physicians treating patients with descending TAA, in the durability and effectiveness of the Valiant Thoracic Stent Graft System," said Dr. Conrad. "The five-year data demonstrate a high rate of freedom from aneurysm-related mortality and rare incidences of rupture or conversion to open surgery."

A TAA is a dangerous weakening and subsequent bulge in the aorta (the body’s main artery) near where it branches off the heart; those that rupture usually result in death. An estimated 60,000 people in the U.S. alone have a TAA. Those aneurysms that are detected before rupturing can usually be effectively treated with stent grafts or invasive surgery.

VALOR II is a prospective, single-arm study that involved 160 patients at 24 U.S. medical centers. It was designed to evaluate the safety and effectiveness of the Valiant Thoracic Stent Graft System for thoracic endovascular aortic repair (TEVAR) of aneurysms in the descending thoracic aorta.

Key VALOR II five-year follow-up findings include 94.8% freedom from aneurysm related mortality, 1.3% rupture rate, 6.9% required secondary procedures, 0.6% (1/160) conversion to open surgery rate, 89.3% of patients had stable or decreased aneurysm size, 0.0% migration reported (defined as >10mm from the 1-month follow-up) and 0.0% loss of integrity reported.

"The Valiant system leverages Medtronic’s 17 years of thoracic stent graft experience and innovation, and is proven in more than 70,000 patients," said Daveen Chopra, vice president and general manager of the Aortic business, which is part of the Aortic & Peripheral Vascular division at Medtronic.

"The VALOR II study proves the durability of the system and our commitment to clinical research and improving patient outcomes with an objective to settle for nothing less."

The Valiant Thoracic Stent Graft System is indicated for the endovascular repair of all lesions of the descending thoracic aorta in patients having appropriate anatomy, including: iliac or femoral access vessel morphology that is compatible with vascular access techniques, devices, and/or accessories, non-aneurysmal aortic diameter in the range of 18-42 mm and non-aneurysmal aortic proximal and distal neck lengths >= 20 mm.