[Hydrodynamic investigations of the current mechanical artificial heart valves]

The work presents results of comparative investigations of the integral hydrodynamic characteristics of the best for today domestic mechanical heart valve (MHV) Medinzh-2 (MI-2) and the turn-disk domestic MHV--LIKS-2, EMIKS (E) and foreign MHV--Medtronic-Hall, Bjork-Shiley (BS), Sorin (SO) and bicuspid valves--St. Jude Medical (SJ), Carbomedics in the stationary and in the pulsatile flows. It was found that according to the main hydrodynamic characteristics including the outlet flow structure, MHV MI-2 was substantially superior to MHV E, BS and SO, and by certain characteristics it approximated to the best foreign MHV SJ. Like all mechanical heart valves, the valve MI-2 disturbs the uniformity of the inlet flow and forms a complex non-stationary flow with detached zones, areas of great shear stresses, with vortex structures of different types, and hence the task of hydrodynamic optimization of its construction is thought to become actual. The comparison of clinical parameters of work of the valve MI-2 with its hydrodynamic characteristics confirms its high hemodynamic effectiveness and thrombo-resistance in patients at long-term periods of follow-up, taking into account the adequate correction of disbalance of hemostasis.