Medtronic Begins Feasibility Study of Valiant Mona LSA Branch Thoracic Stent Graft System

April 21, 2015—Medtronic plc announced the start of a feasibility study to evaluate the safety and effectiveness of the Valiant Mona LSA branch thoracic stent graft system, an investigational device designed to enable a completely endovascular solution for thoracic aortic aneurysms (TAAs) encroaching on the left subclavian artery (LSA).

The purpose of the study is to characterize the safety and effectiveness of the investigational device acutely and at 30 days. The study aims to enroll 24 patients at up to seven sites in the United States. Use of the Valiant Mona LSA branch thoracic stent graft system is limited to the current study approved by the United States Food and Drug Administration (FDA) under an investigational device exemption, advised Medtronic.

Eric Roselli, MD, of the Cleveland Clinic in Cleveland, Ohio, serves as the study’s national primary investigator. Dr. Roselli completed the first implantation in the study on April 16. In Medtronic’s press release, Dr. Roselli commented, “TAAs involving branch vessels such as the LSA can be particularly challenging to treat. The use of an off-the-shelf stent graft system with a built-in branch has the potential to simplify this challenge by eliminating the routine requirement for surgical LSA bypass.”

According to the company, the Valiant Mona LSA device, which is based on Medtronic’s Valiant Captivia thoracic stent graft system, consists of a main graft for placement in the aneurysmal segment of the aorta and a branch graft for placement in the LSA. In their deployed state, the system’s two pieces fit together to exclude the aneurysm and maintain patency of the LSA. The main graft features a tapered opening, or cuff, that is oriented toward the LSA. The branch graft fits inside the cuff and terminates in the LSA. Medtronic noted that coverage of the LSA during endovascular repair of TAAs is necessary in approximately 40% of cases and is associated with a higher rate of neurological complications, according to published reports in peer-reviewed medical journals. As a result, the Society for Vascular Surgery suggests routine revascularization of the LSA in elective cases where achievement of an adequate seal zone for the stent graft requires coverage of the LSA.

The Valiant Mona LSA system has previously been studied as part of an early feasibility pilot program for medical devices initiated by the FDA in 2012. It was one of nine devices selected by the FDA for the program. Results from this previous evaluation were presented in 2013 at the VEITH symposium in New York, New York.

Daveen Chopra, Vice President and General Manager of the aortic franchise in Medtronic’s Aortic and Peripheral Vascular business, stated in the company’s announcement, “The start of this study represents another step forward in our efforts to develop standardized stent graft systems for the treatment of aortic disease involving branch vessels. We remain committed to innovating safe and effective endovascular solutions for these complex clinical challenges in support of vascular interventionists and their patients around the world.”