[Biomechanical and flow characteristics of stentless and stented aortic valve bioprostheses].

A comparative investigation of biomechanical and hydrodynamic characteristics of stentless and stented bioprostheses was carried out. It was demonstrated that stentless bioprostheses are functionally superior to stented ones. The differences between biomechanics and hydrodynamics of the examined stentless bioprostheses "BioLab", "AB-Mono-Kemerovo" and DD2 and stented bioprostheses "Wessex", "KemCor" and "Bionox-2" were shown.

[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.

[Effects of implantation technique on hydrodynamic and biomechanical characteristics of stentless aortic valve bioprostheses in experiments].

A comparative analysis of experiments with biomechanics and hydrodynamic stentless xenografts implanted into the subcoronary position with completely (n = 7) and partially (n = 7) scalloped sinuses was made. The implantation was performed into the human aortic root complexes in vitro. Factors of the influence on biomechanical and hydrodynamic performances of xenografts before and after implantation have been established.

[Age-dependent dynamics of biomechanical and hydrodynamic properties of the valve-aortic complex of man].

A comparative analysis of geometrical, biomechanical and hydrodynamic characteristics of the valve-aortic complexes taken from humans of different age has shown a determining role of distensibility of the aortic root in the functioning of valve cusps. An alteration of geometrical relationships of elements of the aortic root, its less distensibility, worse biomechanical and hydrodynamic characteristics of the aortic valve in humans older than 50-60 years of age is established.

[Should the presence of coiled blood flow in the left heart ventricle and aorta be taken into consideration when constructing artificial heart valves?].

The use of an original device developed by the authors which was introduced in the blood flow in experiments in dogs has confirmed the presence of coiled blood flow in different parts of the aorta. The rate, direction and angle of coiling were calculated. The results obtained suggest that the fact of coiling the blood flow should be taken into account when constructing new models of artificial valves of the heart in order to decrease the energy value of the cardiac output, to prevent injury of the formed elements of blood and thrombogenesis.