TAVR vs. SAVR Study of VitaFlow Liberty® for Severe BAV Stenosis

Inclusion Criteria: 1. Subject aged ≤ 75 years; 2. With symptomatic severe bicuspid aortic stenosis, defined as: peak flow velocity ≥ 4.0m/s, or mean trans-aortic pressure gradient ≥ 40mmHg, or aortic orifice area (AVA) ≤ 1.0cm2 (or AVA index ≤ 0.6cm2/m2) confirmed by echocardiography； 3. New York Heart Association (NYHA) cardiac function classification ≥ Class II; 4. With an intermediate or low risk of surgical procedures (STS score ≤8%) assessed by the local heart team; 5. Voluntarily participate in this study and sign the informed consent form. Exclusion Criteria: 1. Known allergy or resistance to study device and control device components such as nitinol or contrast media; 2. Known contraindication or allergy to anticoagulant or antiplatelet medications and inability to tolerate the anticoagulant or antiplatelet therapy; 3. Known presence of active infective endocarditis or other active infection; 4. Known presence of severe vascular disease that precludes safe implantation of the prosthetic valve; 5. Ascending aorta width ≥50mm; 6. Previous prosthetic valve implantation (mechanical or bioprosthetic) in any heart place; 7. The aortic root anatomy not suitable for transcatheter aortic valve implantation confirmed by preoperative imaging (including aortic root calcification that influence the sufficient dilatation of the rposthetic valve); 8. Intracardiac mass, left ventricular or left atrial thrombus, vegetations confirmed by preoperative echocardiography; 9. Acute myocardial infarction (defined as Q-wave MI or non-Q-wave MI) within 30 days prior to surgery; 10. Invasive therapeutic cardiac surgery within 30 days prior to surgery (except for temporary pacemaker or implantable cardioverter-defibrillator implantation); 11. Clinically diagnosed stroke or TIA within 3 months prior to surgery; 12. Gastrointestinal bleeding requiring hospitalization or transfusion therapy or other clinically significant bleeding or coagulation disorders within 3 months prior to surgery, which preclude the required antiplatelet therapy in the study; 13. Comorbid with severe native coronary artery lesions that require revascularization therapy; 14. Comorbid with severe mitral or tricuspid regurgitation; 15. Comorbid with cardiogenic shock or hemodynamic instability requiring support from positive inotropic agents or mechanical ventilation or mechanical cardiac assistance; 16. Comorbid with severe left ventricular dysfunction (defined as left ventricular ejection fraction LVEF \<20%); 17. Comorbid with end-stage renal diseases requiring chronic dialysis; 18. Comorbid with blood dyscrasias defined as leukopenia (white blood cell count \< 3×109/L), thrombocytopenia (platelet count \< 50×109/L), history of bleeding diathesis or coagulopathy, or hypercoagulable states; 19. Subjects corresponding to the criteria of a vulnerable population (including patients who are unable to fully understand all aspects of the study, patients lacking capacity in the informed consent procedure and patients with dementia and cognitive impairment); 20. Female subjects known to be pregnant or lactating; 21. Life expectancy is less than 12 months as assessed by the investigator; 22. Subject is participating in or planning to participate in other drug or device clinical studies within 12 months postoperatively; 23. Any other condition that, at the discretion of investigator or heart team, may preclude the subject's safe participation in the study.