The development of heart valve prostheses has dramatically changed the care of patients with valvular heart disease. A great deal of progress has been made during the past 30 years in the design and development of materials for mechanical valves and in the preparation and design of biologic tissue valves in an attempt to fulfill the requirements of an ideal prosthesis: adequate flow characteristics, durability, biocompatibility, resistance to thrombosis, ease of insertion, and silence. Numerous prosthetic valves have achieved clinical acceptance at one time or another. The variety of available prostheses attests to the inability of any single existing design to fulfill the requirements of an ideal prosthesis. The valve substitutes in use today function remarkably well, but each type of prosthesis has some disadvantages. The characteristics of the valve substitute often dictate the selection of one prosthesis in preference to others in a particular patient. The prosthetic valve designs available today are of two major types, mechanical and tissue valves. The mechanical prostheses include the caged-ball, tilting-disc, and bileaflet valves. Tissue valves include porcine and pericardial valves. In addition, allografts (aortic homografts) and autografts (pulmonic valve) are available for aortic valve replacement.

Numerous new valves have been introduced and many older models have been modified repeatedly in an attempt to reduce the incidence of complications. Some of the new valves as well as some of the modifications to older models have resulted in improved performance. Not all modifications or new valves have been improvements, however; some changes associated with improvements in one aspect of valve performance have simultaneously had a negative impact in another area. Some of the problems associated with new valves have not been discovered until large numbers of these prostheses have been implanted in patients. The rigorous evaluation demanded by the Food and Drug Administration (FDA) from the manufacturers of new valves is an attempt to decrease the chance of this occurring in the future. It is unlikely that a major revolution in valve design will occur; a slow evolution in valve design is much more likely.

Although hundreds of thousands of heart valves have been implanted (> 50,000 are implanted annually in the United States alone), information on valve performance is not conclusive because only a small percentage of this experience has been compiled and reported, prospectively or retrospectively. A comprehensive review of the literature permits only some general statements to be made. This article reviews the characteristics of the most commonly used valve prostheses and concludes with guidelines for the selection of a prosthesis for an individual patient.