The current status of the VALOR Thoracic Endograft Trial was presented at Charing Cross by Dr Ron Fairman, Associate Professor of Surgery and Chief, Division of Vascular Surgery Hospital of the University of Pennsylvania, Philadelphia.The VALOR (Medtronic Ave Talent Thoracic Stent Graft System for the Treatment of Thoracic Aortic Aneurysms) trial is testing 144 patients, with a registry arm of 150 patients and a high risk arm of 100 patients, to determine whether the Talent Thoracic stent graft is a safe and effective method of treating thoracic aortic aneurysms (TAA) in patients who are eligible for surgical repair whom are low to moderate risk.
Fairman presented important lessons that had emerged from the trial so far. Difficulty in deploying stent in proximal arch positions (curvature) and problems with arch conformability resulted in with engineering modifications to the closed web proximal option and exoskeleton, removal of the connecting bar and optimising of stent spacing.
Longer devices were needed to treat extensive disease and to limit number of modular connections. Engineering modifications included developing a graft length of up to 200 mm and an Xcelerant Delivery catheter providing mechanical advantage with precise deployment, reduced catheter size (20-24 Fr) and reduced stroke potential.
Difficulty in identifying proximal and distal aspects of components once inserted was resolved with figure eight marker proximally and zero marker distally modifications. Engineering modifications to address arch flexibility and bare Spring release/flip included increased spring peaks (8) and developments to the inset proximal stent.
Concluding, Fairman said the current design has excellent deliverability and performance and that enhancements in stent-graft design are still occurring.
He said allowing more precise placement could potentially reduce complications. Fairman also commented on iliac issues, delivery catheter size, how access strategies are crucial in treating patients and the higher TAA prevalence in women.
Full results of the VALOR trial will be reported at the forthcoming annual meeting of the Society for Vascular Surgery (SVS) in Chicago in June.