Medtronic's Valiant thoracic stent graft system delivered positive clinical results through one year of patient follow-up in the company's U.S. pivotal study, VALOR II, according to data presented at a meeting for vascular surgeons. The study met all of its prespecified endpoints. The primary safety and effectiveness endpoints were 12-month all-cause mortality and 12-month successful aneurysm treatment defined as the absence of aneurysm growth (>5 mm) at one and 12 months, and type I and/or type III endoleak for which a secondary procedure was performed or recommended at or before the 12-month visit. Medtronic release