It is 40 years since Starr and Edwards' description of successful prosthetic valve replacement in 1961. Some patients who underwent valve replacement with the original Starr-Edwards prosthesis in the 1960s are alive to this day. The Starr-Edwards ball and cage prosthesis, albeit in modified form, is still available commercially. Each year more than 6000 patients in the UK and 60 000 in the USA alone undergo valve replacement surgery. In the last 40 years more than 80 models of prostheses have been developed for patients requiring valve replacement.1,2 Mitral valvotomy for mitral stenosis predated the introduction of heart valve replacement, and valvotomy can now usually be achieved percutaneously with balloon dilatation in selected cases. Additionally techniques for repair of the diseased mitral valve, particularly mitral valve prolapse, have been developed and refined, avoiding the need for valve replacement. The morbidity, mortality, and long term results of valvotomy or valve repair in suitable patients are better than for valve replacement and should be used in preference when possible. Choice of operation and the prosthesis used for those undergoing valve replacement is important for each individual patient and ideally should be made together by the patient, cardiologist, and surgeon. This article deals with choice of prosthesis for the individual patient. Other articles in this series deal with the medical management of valvar heart disease,3 anticoagulant control,4 late results and late complications of valve replacement,5 and management of endocarditis.6 ### Mechanical prostheses #### Ball valves The original Starr-Edwards prosthesis comprised a silastic ball which seated in the sewing ring when closed and moved forward into the cage when open (fig 1). The original design has gone through several modifications but the basic design remains similar to the original. More than 200 000 have been implanted. Figure 1 Common types of heart valve prostheses: St Jude's …