Mitral valve replacement with complete retention of native leaflets

Severe Intermittent Transvalvular Mitral Valve Regurgitation: Serious Complication of Mitral Valve Replacement With Subvalvular Preservation

Mitral valve replacement with subvalvular preservation is a favorable technique to protect left ventricular function and improve long-term survival. However, complications of the procedure should be considered. We report the case of a patient with a history of prosthetic mitral valve replacement with severe intermittent transvalvular mitral regurgitation and reduced ejection fraction. (Level of Difficulty: Advanced.)

Importance of preservation of chordal apparatus in mitral valve replacement

Mitral valve replacement often involves disruption of the chordal apparatus with disturbance of the annulo-papillary continuity. This results in significant downgrading of ventricular function. Analyzes various reports to accurately assess the advantages of chordal preservation. This review briefly briefly reviews the surgical techniques. The advantages of chordal preservation are analyzed, with particular emphasis on the technical difficulties and potential complications involved.

Papillary muscle repositioning in valve replacement for left ventricular dysfunction: ischemic mitral regurgitation

BACKGROUND

The aim of this study was to investigate the feasibility of performing papillary muscle repositioning (PMR) for subvalvular-sparing mitral valve replacement procedures in patients with ischemic mitral regurgitation and to determine the early and late effects of this procedure on the clinical outcome and left ventricular mechanics.

METHODS

We prospectively randomly allocated 50 patients with severe ischemic mitral regurgitation and left ventricle dysfunction who were candidates for coronary artery bypass graft surgery and mitral valve replacement into a total chordal-sparing mitral valve replacement group or a PMR group. Echocardiography was performed preoperatively, at discharge, and after 3 years to determine the left ventricular dimensions, shape, and function.

RESULTS

The reduction in the left ventricle volumes and sphericity index in the PMR group was more significant than that in the other group. With regard to the left ventricular end-systolic and left ventricular end-diastolic volumes, sphericity index, and ejection fraction, the PMR group showed better results (p < 0.05), but the difference in New York Heart Association functional class after 3 years was not statistically significant between the two groups (p > 0.05).

CONCLUSIONS

The PMR technique described herein can dramatically help ischemic patients by affecting the left ventricular shape and function more efficiently compared with the complete retention of the mitral subvalvular apparatus if the mitral valve is to be replaced.

Technique and outcome of mitral valve replacement in dogs

Eight dogs with naturally occurring severe mitral regurgitation underwent mitral valve replacement with a mechanical valve prosthesis during cardiopulmonary bypass. Dogs received warfarin orally after surgery to maintain a prothrombin time-based international normalized ratio from 2.5 to 3.5. Seven dogs survived surgery. Left ventricular diastolic volume index decreased significantly from 206 +/- 91 mL/m2 before surgery to 121 +/- 47 mL/m2 after surgery. Left atrium-to-aorta ratio decreased significantly from 2.66 +/- 0.4 before surgery to 1.73 +/- 0.65 after surgery. Left ventricular systolic volume index was not significantly different after surgery (56 +/- 36 mL/m2), compared with before surgery (40 +/- 32 mL/m2). Median survival after surgery was 4.5 months (range, 0.75 months to 5.25 years). Six dogs died of confirmed or suspected thrombosis of the valve prosthesis. Dogs with severe mitral regurgitation tolerated mitral valve replacement well, but a high incidence of prosthetic valve thrombosis limited long-term outcome.

Both Leaflet Preservation During Mitral Valve Replacement:. Modified Anterior Leaflet Preservation Technique

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.

Entrapment of mitral chordal apparatus causing early postoperative dysfunction of a St. Jude mitral prosthesis

Preservation of subvalvular apparatus is increasingly performed during mitral valve replacement. We describe a case of early postoperative St. Jude mitral valve dysfunction as a result of chordal entrapment.

Severe intermittent intraprosthetic regurgitation after mitral valve replacement with subvalvular preservation

Preservation of the subvalvular apparatus during mitral valve replacement preserves left ventricular function and improves long-term survival. Complications of subvalvular preservation include left ventricular outflow tract obstruction and prosthesis impingement. We report a case of severe intermittent intraprosthetic mitral regurgitation detected by transesophageal echocardiography after mitral valve replacement by a bileaflet mechanical prosthesis with subvalvular preservation. Intravalvular prosthetic valve regurgitation was caused by remnants of the subvalvular apparatus, which were shown at reoperation to interfere with prosthetic leaflet motion and which were excised. Postoperative transesophageal echocardiography showed neither abnormal mitral regurgitation nor residual mass. The use of intraoperative transesophageal echocardiography could enable the detection of this rare complication.

Is posterior leaflet preservation in the surgical treatment of rheumatic mitral insufficiency without left ventricular dysfunction necessary?

Preservation of the mitral valve leaflet and tensor apparatus during valve replacement is believed to maintain left ventricular performance. To determine the effect of posterior leaflet preservation in pure severe mitral insufficiency without left ventricular dysfunction 56 patients were operated on between 1993 and 2000. Twenty-three patients underwent mitral valve replacement with posterior chordal preservation and 33 patients underwent mitral valve replacement with chordal transection. Preoperative data in the both groups were similar. After 30days there were no mortalities observed. Dimensions of the left ventricle had significantly decreased within one group, but there was no difference in the other group. The improvement of the functional and cardiac performance in all patients was significant without any difference between the two groups. Actuarial freedom from death was not significantly different at 6yr (P=0.23). To preserve left ventricular function in pure severe mitral regurgitation without left ventricular dysfunction, mitral valve replacement is very effective with or without posterior leaflet preservation. But, it is difficult to suggest that posterior leaflet preservation alone can increase cardiac performance.

Left ventricular outflow tract obstruction with mitral mechanical prosthesis

Left ventricular outflow tract obstruction after mitral valve replacement may occur when the native mitral apparatus is preserved intact. Although it has usually been reported using bioprostheses, we present one case using a low-profile mechanical prosthesis. The reduction of left ventricular dimensions and valvular redundancy contributed to this complication. We obtained definitive relief of left ventricular outflow tract obstruction by transaortic exposure and partial resection of the obstructing tissue with the help of video-assisted cardioscopy.

Preservation of anterior and posterior leaflet in mitral valve replacement with a tilting-disc valve

An operative technique for mitral valve replacement with preservation of chordae tendineae to both the anterior and posterior leaflets is described. The anterior mitral valve leaflet is completely detached from the annulus and divided into three to four islands of tissue, each with attached chordae tendineae. These islands are transposed under the posterior leaflet and secured with 4-0 polypropylene sutures. The posterior leaflet is completely preserved with no division or manipulation. This technique allows safe implantation of tilting-disc or bileaflet prostheses with excellent preservation of left ventricular function.