Chordal‐Sparing Mitral Valve Replacement Using Artificial Chordae Tendineae for Rheumatic Mitral Stenosis: Experience of the “Oblique” Method

Abstract

Chordal-sparing mitral valve replacement (CSMVR) has been proven to be beneficial for postoperative left ventricular (LV) function. In patients with mitral stenosis, however, diseased chordae tendineae (CT) often have to be replaced using artificial CT to achieve CSMVR. Previously, we reported that resusupension of artificial CT in an oblique direction enhances systolic LV function. Among 40 consecutive patients with mitral valve replacement (MVR), 17 (4 men and 13 women; mean age 66.5 years) with rheumatic mitral stenosis underwent CSMVR with oblique resuspension. Echocardiography was done before the operation, early (mean 25 days) after the operation, and at a late stage (mean 14 months). There was no mortality or major morbidity. LV ejection fraction late after the operation (68 +/- 8%) was better than that in the early period (61 +/- 8%, p < 0.01), and comparable to the preoperative level (65 +/- 9%). The oblique method may help to improve the results of MVR.

Papillary Muscle Repositioning as a Subvalvular Apparatus Preservation Technique in Mitral Stenosis Patients with Normal Left Ventricular Systolic Function

“…They showed that MVR with preservation of chordae tendineae can be expected to have a beneficial effect on postoperative LV performance in mitral stenosis patients. In another study, Soga and associates 13 reported the results of chordal-sparing MVR performed by using artificial chordae in 17 patients who presented with rheumatic mitral stenosis and preserved LV systolic function. At 14 months' follow-up, the LV dimensions and the LVEFs of patients who had undergone chordal-sparing MVR were comparable to their preoperative levels.…”

“…However, experimental data have shown that interruption of the continuity between the mitral annulus and papillary muscles leads to deterioration of LV systolic function even in normal hearts. 13,21 Therefore, preservation of the subvalvular apparatus could also optimize postoperative LV systolic function in mitral stenosis patients. Of several studies grounded on this assumption, most have shown improvement in postoperative outcome through subvalvular-apparatus preservation, as did our study.…”

“…However, in many patients with mitral stenosis, preservation is difficult because of severe subvalvular damage (shortening, calcification, and thickening). 13,16 Use of a preservation technique that is simple, reproducible, and appropriate for the patient's individual anatomy, pathologic condition, and LV function is paramount. 26 Therefore, patients with a severely diseased subvalvular apparatus could benefit from decalcification of valve tissue, 27,28 use of artificial chordae, 13 or PMR.…”

“…13,16 Use of a preservation technique that is simple, reproducible, and appropriate for the patient's individual anatomy, pathologic condition, and LV function is paramount. 26 Therefore, patients with a severely diseased subvalvular apparatus could benefit from decalcification of valve tissue, 27,28 use of artificial chordae, 13 or PMR. Chordal-sparing MVR (by use of artificial chordate) can be performed regardless of the severity of the subvalvular disease; however, determination of the optimal length of the artificial chordae is an important aspect of this technique.…”

“…In patients with LV dysfunction and mitral regurgitation, several studies 10,11 have shown favorable effects of papillary muscle repositioning on LV remodeling; however, the effect of subvalvular-apparatus-sparing surgery (including PMR) on LV mechanics has not yet been fully elucidated in patients who have isolated mitral stenosis and preserved LV function. 12,13 …”