Designing And Developing of an Indigenous Prosthetic Mechanical Heart Valve

The development of a mechanical prosthetic heart valve started in 1952 when Dr. Charles Hufnagel implanted an acrylic ball valve caged in a plexiglass container into the descending thoracic aorta to replace an aortic valve. Subsequently, in the mid-1960s, the Starr-Edwards caged-ball valve was introduced (sub-Fig. 1a). Later on, many other caged-ball valves came into the market like the Magovern-Cromie, Debakey-Surgitool, Smeloff-cutter, etc. These valves were discarded from the market due to the generation of high pressure drop across the valve and larger turbulent shear stresses [1]. The tilting disc valve then came into the market, which Bjork Shiley introduced in 1967 (sub-Fig. 1b). However, many cases of hazard functions and mechanical failures were reported for this valve, thereby repudiating it from the market. After the era of tilting disc valves, bileaflet valves were introduced in 1979. The most common bileaflet valve is the St. Jude Medical valve (sub-Fig. 1c). This valve has better functionality than those of ball and tilting disc valves. However, still, it shows the thrombus formation, particularly in the hinge region, which directly affects its durability, hemodynamics, and functionality. In India, the only commercial mechanical prosthetic heart valve which is developed and manufactured is the TTK Chitra valve (sub-Fig. 1d). However, studies on this valve show that it can cause various valve-related complications like thromboembolic episode, infective endocarditis, thrombosis, hemorrhage, and even death [2]. Hence, it is imperative to increase the performance of a prosthetic mechanical heart valve through a better design and development, which is the primary aim of my current research work.

Figure 1: Different types of prosthetic mechanical heart valves. (a) Caged-ball valve, (b) Tilting disc valve, (c) Bileaflet valve, and (d) TTK Chitra valve manufactured in India.

References:

[1] A. P. Yoginathan, Cardiac valve prosthesis. In Handbook of Biomedical Engineering, CRC Press, New York, 1995, 1847-1870.

[2] P. Kumar, B. Dalvi, R. Chikkatur, P. Kandhachar, R. Parida, V. Ahuja, U. E. Jadhav, A. Tendolkar, TTK Chitra tilting disc valve:hemodynamic evaluation, Indian Journal of Thoracic and Cardiovascular Surgery, 20 (2004) 117121.