Endovascular Reconstruction from Aortic Valve to Aortic Arch Using One-Piece Valved-Fenestrated Stent Graft with a Branch: A Proof-of-Concept Study

Abstract

Objective: To explore the feasibility of endovascular reconstruction of aortic root including aortic valve, sinus of valsalva and ascending aorta by a single stent-graft, a novel valved stent-graft with two fenestrae for preserving the coronary arteries was designed and performed in-vitro on a pig heart based circulation simulating system. Methods: Pig hearts were harvested from 30 healthy adult female pigs weighing between 60-65 kilograms. Before sacrifice, all the pigs received aortic computed tomography angiography (CTA) examinations and morphologic parameters of aortic root were measured. Then we customized the valved stent-grafts according to the CTA measurements. After the pig heart was fixed on the special platform according to the original orientation and connected to the circulation system, the stent graft was delivered through transapical access and covered the segment from aortic annulus to proximal part of aortic arch under DSA (digital subtraction angiography) guidance. Then changes of coronary flow before and after the procedure and fenestration alignment with coronary ostia were analyzed. Results: The overall technical success rate was 100%. The valve functions tested by ultrasound were in good condition under 120 mmHg circulation pressure. The flow of left coronary artery (LCA) did not decrease, but increased after the stent-graft implantation (340 ± 2.06 mL/min versus 288 ± 5.29 mL/min, P < .05). Similarly, the flow of right coronary artery (RCA) also increased (392 ± 9.17 mL/min versus 348 ± 8.01 mL/min; P < .05). The final angiography confirmed that both coronary arteries were patent. When generally observed from outer wall of valsalva sinus, both RCA and LCA orifices were aligned with the fenestrae. In 4 cases, the autologous valve leaflets blocked nearly 20% of the LCA fenestra’s area, but the flow did not significantly decrease in these cases. Conclusion: Stimulated on a pig heart-based circulation simulation system, the one-piece valved-fenestrated stent graft with a branch could be delivered via the transapical access and deployed accurately, which achieved endovascular reconstruction of aortic valve, sinus of valsalva and ascending aorta while preserving the coronary artery perfusion by fenestrations. More in-vivo experiments on animal models are mandatory to further verify its efficacy and safety.