Valve Replacement

Abstract

Valve replacement (VR) has been described as the greatest single advance in the treatment of valvular heart disease [34]. Indeed, since the introduction of the caged ball prosthesis in 1960 [44] almost half a million Substitute cardiac valves have been implanted [36]. Improved intra-operative techniques and post-operative management have resulted in a striking decrease in hospital mortality. When successful, VR relieves Symptoms and there is objective evidence for improvement in several haemodynamic variables. However, although immense strides have been made in the quality and design of prostheses, there is still no ideal valve Substitute. The three main goals for prostheses, namely, freedom from thrombogenicity, long-term wear and haemodynamic restriction have not yet been attained in a single valve. Thus, to a degree, the patient is exchanging one disease process for another. In 1970, at the World Congress of Cardiology, McGOON stated that, “Concern and uncertainty remains a prevalent attitude to the selection of a Substitute heart valve” [29]. While this attitude persists almost a decade later, non valve-prosthesis related (VPR) factors have assumed increasing importance in determining late survival following VR.

Supported in part by the Stella and Paul Loewenstein Cardiac Trust Fund of the University of the Witwatersrand, Johannesburg.