Contents:

»

1. Article Information, Introduction, Background

2. Current Bioprostheses

3. Mechanical Prostheses

4. Transcatheter Heart Valve Therapies, Aortic Valve Replacement

5. Mitral Valve Reconstruction

6. Annuloplasty Prostheses For Valvular Reconstructive Surgery

7. Technological Advances, Clinical Performance, Summary of Experience

8. Indications for Prostheses Choice, Conclusion

9. References

Indications for Prosthesis Choice

Mitral Valve Replacement—Freedom from valve related reoperation and valve related mortality favours mechanical prostheses for all age groups except in patients >70 years. Valve-related morbidity, due to neurologic or functional impairment, does not differentiate between bioprostheses and mechanical prostheses.

Aortic Valve Replacement—Freedom from valve related reoperation and valve related mortality did not differentiate bioprostheses and mechanical prostheses in patients ³60 years. Comparative evaluation of the prostheses types gives high priority for bioprosthesis in patients ³60 years based on improved morbidity profile. The evaluation extended the recommendation for bioprostheses in aortic valve replacement to include patients ³60 years.

Conclusion

The device management of valvular heart disease remains active and even exciting at this stage of endeavour. The concept of patient-prosthesis mismatch has been of major concern to Surgeons and Cardiologists. Industry has responded with diameter-enhanced mechanical prostheses and porcine and pericardial bioprostheses. It remains unknown as to whether control of patient-prosthesis mismatch will result in improved survival. There has been a dramatic increase in the use of bioprostheses, more so in North America than in Europe. Industrial scientists have made a major endeavour in attempting to control calcification and tissue stress of biological tissue in an attempt to retard the development of structural valve deterioration, which results in valve failure and potential reoperation. Expansion of the age of our general population has led to consideration that not only are bioprostheses suitable for the elderly, but, in some circumstances, mechanical prostheses should be considered in the presence of likely extended longevity. The introduction of patient managed anticoagulation has made mechanical valve prostheses safer with lower instances of thromboembolism and anticoagulant related hemorrhage. There also has been extensive development in the technology to evaluate and develop the hinge mechanisms of mechanical valves to reduce blood stasis and lower that risk of major thromboembolism and thrombosis. The role of autografts remains paramount, especially in children, and yet to be proven in young adults, whereas allografts have been identified to develop structural deterioration somewhat similar to heterografts. This information places the role of allografts predominantly for the management of native and prosthetic valve endocarditis. With the supply issue, this has been acceptable. Mitral valve surgery remains predominantly reconstructive surgery, inclusive of surgery for degenerative disease and all levels of ischemic disease from grades II-IV. The surgical procedures will have to take into account consideration of the ventricular component of ischemic disease, as well as surgical restoration for advanced cardiomyopathy of all etiologies. Transcatheter technologies continue to advance, and the role of these procedures will need to be determined in relation to conventional surgery with identification of specific indications for both transcatheter and conventional surgery.