Transesophageal Doppler Echocardiography in the Evaluation of Mitral Bileaflet Mechanical Prostheses: Comparative Studies between Sorin Bicarbon and ATS Valve Prostheses in Mitral Valve Replacement

ABSTRACT

BACKGROUND: The intraoperative TEE is frequently used as a preoperative diagnostic technique and for intraoperative assessment of surgical results. However, the clinical studies regarding assessment of mitral prostheses in the immediate postbg>ass period by TEE have been few, and there is no comparative data between curved(Sorin Bicarbon) and rotatable flat(ATS) bileaflet mechanical prostheses. The purpose of this study is to compare forward flow hemodynamics and complications including regurgitation between Sorin Bicarbon and ATS mitral prostheses by using Doppler and color-flow imaging TEE. METHOD: 23 patients with Sorin Bicarbon(Group I) and 16 patients with ATS(Group II) were studied by transesophageal Doppler echocardiography in the operating room. We measured the peak velocity & gradient, mean velocity 8c gradient and mitral valve area by pressure halt-time method after replacement of mitral prosthesis using Doppler echocardiography and determined the paravalvular regurgitation using color-How imaging. All transesophageal studies were performed about 20 minutes after termination of the cardiopulmonary bypass. RESULTS: There were no statistical differences(p<0.05) between the two groups in Doppler parameters. Mean transmitral gradient of Group [(2.31.2mmHg) was same as Group II. Mean mitral valve area(same as effective oriface area) calculated by pressure half-time method was 3.1+/-0.6 vs 3.0+0.9cm in Group I vs II. There was one prosthetic malfunction in Group II whose peak and mean gradient were 13 and 5mmHg respectively, and the mitral valve area was 2.8cm. Paravalvular and transvalvular regurgitation were not seen in both groups in operating room. CONCLUSION: In this study, we evaluated functional differences between curved(Sorin Bicarbon) vs flat(ATS), bileaflet mechanical prostheses in MVR by using Doppler and color flow imaging TEE. We conclude that both valves provided excellent hemodynamic profiles and there were no significant functional differences between them. Valve-related mechanical complications in both will need further studies.