Surgical mitral valve repair technique considerations based on the available evidence

Abstract

Mitral valve regurgitation is the second most common valve disease in the western world. Surgery is currently the best tool for generating a long-lasting elimination of mitral valve regurgitation. However, the mitral valve apparatus is a complex anatomical and functional structure, and repair results and durability show substantial heterogeneity. This is not only due to differences in the underlying mitral valve regurgitation pathophysiology but also due to differences in repair techniques. Repair philosophies differ substantially from one surgeon to the other, and consensus for the technically best repair strategy has not been reached yet. We had previously addressed this topic by suggesting that ring sizing is "voodoo". We now review the available evidence regarding the various repair techniques described for structural and functional mitral valve regurgitation. Herein, we illustrate that for structural mitral valve regurgitation, resuspension of prolapsing valve segments or torn chordae with polytetrafluoroethylene sutures and annuloplasty can generate the most durable results paired with the best achievable hemodynamics. For functional mitral valve regurgitation, the evidence suggests that annuloplasty alone is insufficient in most cases to generate durable results, and additional subvalvular strategies are associated with improved durability and possibly improved clinical outcomes. This review addresses current strategies but also implausibilities in mitral valve repair and informs the mitral valve surgeon about the current evidence. We believe that this information may help improve outcomes in mitral valve repair as the heterogeneity of mitral valve regurgitation pathophysiology does not allow a one-size-fits-all concept.

Keywords: Degenerative mitral regurgitation; functional mitral regurgitation; mitral valve repair.

Figure 1. (a) Intraoperative images of the valvular and (b-d) subvalvular units of the mitral valve.

Figure 2. (a) Mitral valve repair with leaflet resection and (b) chordal replacement by Schubert et al.[35]

Figure 3. (a) Forest plot comparing implanted annuloplasty ring size diameter and (b) mean mitral gradients in mmHg at follow-up after chordal replacement or after leaflet resection techniques. Adapted from Mazine et al.[44]

Figure 4. (a) Illustration of papillary muscle displacement by functional MR, and surgical strategies addressing the subvalvular apparatus; (b) relocation of the posterior papillary muscle;[74] (c) schematic illustrations depicting three-dimensional anterior and posterior papillary muscles displacement vectors in experimental ovine models of ischemic MR and functional MR;[86] (d) Ring and String technique;[76] (e) Girdauskas technique;[91] (f) Ring-Noose-String technique.[19] MR: Mitral regurgitation; LA: Left atrium; LV: Left ventricle; APM: Anterior papillary muscle; PPM: Posterior papillary muscle; FMR: Functional mitral regurgitation.