Background: Satisfactory results of bileaflet preserving mitral valve replacement (MVR) had forced several institutes to preserve both leaflets during MVR. Modifications were required to prevent the preserved tissue from interfering with prosthetic valve function, to implant an adequate size of valve and to prevent left ventricle outflow tract (LVOT) obstruction.
Materials and methods: Conventional MVR was performed to 51 patients (group 1) and bileaflet preserving MVR was performed to 43 patients (group 2). Mitral anterior leaflet incised from the middle of the leaflet to mitral annulus without chordal injury in group 2 patients. Sutures were placed through the mitral annulus first and then passed from the bottom to the tip of anterior leaflet. Posterior leaflet was also preserved. Prosthetic valve was put down into the mitral annulus and sutures were ligated. Excessive anterior leaflet tissue was attached to left atrial wall.
Results: Cross-clamping time was 45 +/- 5.33 minutes versus 61.32 +/- 4.43 minutes (p = 0.0001) and total cardiopulmonary bypass time was 60.80 +/- 4.44 minutes versus 80.55 +/- 3.65 minutes (p = 0.0001) in groups 1 and 2, respectively. Inotropy requirement was higher in group 1 (p = 0.0058). When compared with preoperative values postoperative left ventricle ejection fraction (LVEF) increased both at rest (from 52.74% +/- 3.88% to 62.86% +/- 3.18%, p = 0.0001) and during exercise (from 53.16% +/- 3.16% to 64.11% +/- 2.46%, p = 0.0001) in bileaflet preserving MVR group. But in conventional MVR group LVEF decreased postoperatively both at rest (from 51.45% +/- 4.27% to 48.27% +/- 3.35%, p = 0.0001) and during exercise (from 54.47% +/- 7.36% to 42.96% +/- 3.58%, p = 0.0001).
Conclusion: Leaflet preserving MVR operation not only improves the left ventricular performance but also reduces the mortality and morbidity after MVR. LVEF increases both at rest and during exercise. Risk of LVOT obstruction can be completely eliminated with our simple technique.