The first-in-man experience with a new branched thoracic aortic arch stent graft was performed on 11 April 2013 at the Carolinas HealthCare System’s Sanger Heart & Vascular Institute, Charlotte, USA. The procedure with the Medtronic Valiant Mona device, designed with a branch to preserve the left subclavian artery (LSA), was led by Frank Arko.
Two days before the first procedure, Eric Roselli, from the Cleveland Clinic, spoke about the device at the Charing Cross International Symposium (CX35, 6–9 April 2013, London, UK) in the talk “Endovascular management of the left subclavian artery during TEVAR: Valiant LSA branched device”.
“From 17% to 43% of patients undergoing TEVAR have planned coverage of the left subclavian artery,” he said. “Coverage of the left subclavian artery without revascularisation is the single most important predictor of stroke after TEVAR. It can also cause spinal cord ischaemia (4%), arm ischaemia (6%) and death (6%).”
Roselli explained that the Valiant Mosa LSA Stent Graft System has two components: a main stent graft and a branched stent graft. He added, “The Captivia Delivery System has been modified to accommodate two wires; the primary wire delivers the main stent graft and the secondary wire delivers the left subclavian artery branch graft. The secondary wire is inserted into the lumen at the base of the delivery system, extends through the stent graft and exits out the left subclavian artery branch cuff and through the tapered tip. The delivery system includes tip capture consistent with the Captivia design.”
The left subclavian artery branch graft is constructed of a nitinol helical wire formed stent and polyester fabric. It has a distal flare, which mates with the branch cuff to provide good sealing and fixation. The diameters of 10, 12 and 14mm are appropriate for the left subclavian artery diameters ranging from 8mm to 13mm. Roselli said that the branch graft is offered in one length, which accommodates most anatomies. The branch stent graft is delivered with the femoral approach using a modified (longer length) 15F Endurant limb delivery system.
Roselli told CX35 delegates that the Medtronic Early Feasibility Study Valiant Mona LSA Thoracic Stent Graft System will enrol seven to nine patients at two centres (Carolinas HealthCare System’s Sanger Heart & Vascular Institute and Cleveland Clinic). The objectives are to validate the procedure in humans, assess the safety and performance with the device acutely and at 30 days and collect imaging data to augment the current understanding of the technique.
The feasibility study with the device is one of nine chosen by the FDA for a pilot programme to encourage and facilitate early feasibility studies of innovative medical devices for first-in-human trials in the United States.
In the conclusion of his presentation at CX35, Roselli stated that better disease-specific devices are needed. He went on to say that left subclavian artery preservation during TEVAR is important and that the new FDA innovation pathway may allow rapid development and approval process of a left subclavian artery branched graft device.