CardioCel Tri-leaflet Repair Study

Inclusion Criteria: 1. The subject's annular measurements are ≥ 19 mm to \< 27mm as confirmed on pre-op echo and inter commissure distance equal to or bigger than 19mm as confirmed intraoperatively. 2. The subject is suitable for a tri-leaflet repair. 3. The subject has documented moderate-to-severe AS and/or AI. 4. The subject is willing and able to comply with specified follow-up evaluations, including trans oesophageal echocardiography (TEE) if there are inadequate images by transthoracic echocardiography (TTE) to assess the aortic valve. The subject has reviewed and signed the written informed consent form. 5. The subject upon final intraoperative assessment has intracardiac anatomy suitable for tri-leaflet repair using CardioCel. Exclusion Criteria: 1. Greater than 85 years of age at the time of consent. 2. The subject's annular measurements \< 19 mm or \> 27mm. 3. All patients will be excluded who require emergent surgery (within 24 hours of a presentation to an emergency department) for any reason. 4. The subject will be excluded with pre-existing valve prosthesis in the aortic position. 5. Patients requiring repair of other cardiac valves will be excluded. 6. The subject has active endocarditis. 7. Heavily calcified aortic roots or "porcelain aortas" (as evidenced on cardiac echo). 8. Leukopenia with a WBC of less than 3000 cells per microliter. 9. Acute anaemia with a haemoglobin less than 8 g/dL. 10. Platelet count less than 150.000 platelets/microliter. 11. History of a defined bleeding diathesis or coagulopathy or the subject refuses blood transfusions. 12. Active infection requiring antibiotic therapy (if temporary illness, subjects may enrol 2-4 weeks after discontinuation of antibiotics). 13. Subjects in whom trans oesophageal echocardiography (TEE) is contraindicated. 14. Low Ejection Fraction (EF) \< 35%. 15. Life expectancy \< 1 year, or severe comorbidities, such as cancer, dialysis, or severe COPD at the investigator's discretion 16. The subject is an illicit drug user, alcohol abuser, prisoner, institutionalised, or is unable to give informed consent. 17. The subject is pregnant or lactating (non-pregnancy to be confirmed by pregnancy test for all child bearing potential females prior to enrolment). 18. Recent (within 6 months) cerebrovascular accident (CVA) or a transient ischemic attack (TIA). 19. Myocardial Infarction (MI) within one month of trial inclusion 20. Upon intraoperative assessment of the intracardiac anatomy the patient is not suitable for tri-leaflet repair using CardioCel.