Solving Thrombosis Problems and Investigating Backflow in the Bile LeafletMechanical Heart Valve (St. Jude Medical Valve)IntroductionThe past six decades have fostered the rise of remarkable innovations in design and the production of mechanical heart valves that are safe and hemodynamically supportive. Mechanical heart valves have been widely used during this period with the successful implantation of over 100,000 Omni-Brand tilting disc valves and 300,000 Hall brand tilting disc valves since the late 1970s.[1] . In 1977, St. Jude bilateral leaflet valves were introduced and since then, more than 1.3 million pyrolytic carbon valves have been implanted [1]. Patients with enervating disease of the natural heart valves may undergo mechanical or tissue valve replacement. These include stenosis (hardening and calcification of the valves), insufficiency (due to thinning or tearing of the valves), valve defects and infections. This article will focus on mechanical valve replacements.HistoryDr. Charles Hufnagel first implanted his design of the Hufnagel ball valve in 1952. The implant consisted of a methacrylate ball chamber containing a methacrylate ball [Fig. 1]. This bullet material was then replaced with nylon to construct a hollow nylon bullet coated with silicon to decrease mechanical noise. Although a number of these valves were surgically implanted and resulted in low wear, the major disadvantage of this design was that they could only be inserted into the descending aorta to treat aortic insufficiency [2]. Later, in collaboration with Dr. Dwight Harken, Hufnagel worked on stabilizing the ball chamber to prevent negative impacts on the aortic walls. In the late 1950s, the idea of ​​Starr-Edw...... middle of paper... ...horac Surg, 2003.[2] Hufnagel C., Bull Georgetown Univ Med Center, 1951, pp. 128-30.[3] Swanson J., Starr A., ​​Ann Thorac Surg, 1989.[4] Kay J., Tsuji H., Redington J. et al., Brewer LA III, eds. Prosthetic heart valves. Springfield, IL: Charles C. Thomas, 1969.[5] Björk V., Vogel JHK, ed. Cardiovascular Medicine. New York: Raven Press, 1982.[6] Butchart E., J Thorac Cardiovasc Surg, 2001.[7] Emery R., Aaron K., Kroshus T. et al., J Heart Valve Dis, 2001.[8] Duncan J., Cooley D., Livesay J. et al., Texas Heart Ins Jour, 1983.[9] Durrleman N., Pellerin M., Bouchard D. et al., J Thorac Cardiovas Surg, 2004.[10] Dong T., American patent US2014/052443, 2014.[11] Cheng P., Udipi K., Chen M., US Patent US20090232863 A1, 2009.[12] Shin J., et al., Analyst, 2006.[13] Dumont K., et al., J Biomech, 2007.[14] Manning K., et al., Artificial organs, 2003.