Comparative Research On Value Downstream Of The Turblent Shear Stress Difference In Mitral Mechanical Valve Replacement And Mitral Valvuloplasty

Objective:From the point of view of heart valve in fluid mechanics, comparatively study the Hemodynamic indicators in the downstream of the valve of Mechanical valve replacement of mitral valve double leaf and Mitral Valvuloplasty which is to be reserved in different ways and clear for valve downstream of the hemodynamic effects of different surgical procedures.Methods:The objects were55patients treated in our hospital with simple mitral insufficiency from Sep.2010to Dce.2012. There are35patients received the treatment of mitral bileaflet mechanical valve replacement among them, which were divided into3groups according to the different conservative manners as no preservation of subvalvular apparatus group, preservation of posterior subvalvular apparatus group and preservation of the entire mitral sbuvalular apparatus group. The other20patients were received treatment of mitral valvuloplasty. They were divided into valve leaflets forming group and valve ring forming group according to the different forming ways. All patients were tested heart function and flow fields uniformity by doppler ultrasound. Meanwhile, Turblent shear stress (TSS) and relative turbulence intensity (Iren) were detected by computer-assisted image analysis technology. Then it applied statistical analysis method to compare the advantages and disadvantages of valve downstream of hemodynamics among the different groups.Result:1. MVR with preservation subvalvular structure had improved patients’ cardiac function. In a short time after operation, LVEF and MVP had no significant difference.(P>0.05).2. MVR which retained valve structure will cause valve downstream flow disturbance enhancement to some extent, flow field uniformity became worse, TSS and Irel in MVR group is higher than MVP group (P<0.05).Conclusion:1. For preservation subvalvular structure, the recovery ability of patients’ cardiac function in MVR is similar to that in MVP in a short time after operation.2. Iren would be increased to some extent if retaining valve structure, it made the downstream flow field uniformity of artificial valve bad and TSS increased. This influence mainly has shown in preservation of the entire mitral sbuvalular apparatus group.3. For MVP, the values of downstream flow field uniformity, TSS and Iren in valve ring forming group are lowest, and valve leaflets forming group came second.