Current Perspectives on Contemporary Rheumatic Mitral Valve Repair

Abstract

The surgical management of rheumatic mitral valve disease remains a challenge for cardiac surgeons. Durability of mitral valve repair (MVr) is likely compromised not simply due to high technical demand, but surgeon reluctance, despite boasting copious advantages over MV replacement. This comprehensive review aims to evoke a deeper understanding of MVr concepts necessary to abate these limitations and shift mindset towards a more holistic approach to repair. Details of commonly utilized techniques in contemporary MVr for rheumatic heart disease will be discussed. Of importance, the reparative procedures will be mapped to an in-depth physiological exploration of the mitral complex-dynamism and rheumatic interplay. This is further emphasized by outlining the current "aggressive" resection strategy in contemporary rheumatic MVr.

Keywords: mitral valve; rheumatic heart disease; rheumatic valve; valve repair.

Fig. 1

(a) Intraoperative antero-lateral commissurotomy being performed, and (b) a schematic illustration of how commissurotomy is performed at our institution. The blue arrows depict symmetrical traction, applied by using nerve hooks around the major chordae on the left and right side of the anterior mitral leaflet perpendicular to the inter-trigonal line; this will create areas of dimpling, depicted by the blue markings, subsequently identifying the trigones (orange zones). The red dotted line represents the ideal point up to which commissurotomy should be performed, determined by stopping 3 to 5 mm from the annulus and 2 to 3 mm laterally from the trigone, as represented by the red bars. The commissural leaflets (C1 and C2) are outlined in grey to highlight the importance of preserving the commissural chords.

Fig. 2

Systolic ventricular pressure distribution on mitral leaflets in (a) dipped coaptation and (b) edge-to-edge coaptation. The black arrows show the ventricular pressure that both mitral leaflets must counter to prevent regurgitation, which is greater in (b). The pink arrows in (a) represent the equal and opposite forces against the anterior and posterior mitral leaflet edges that nullify the ventricular pressure at those points. Note the larger left ventricular outflow tract in (a) with dipped coaptation, decreasing resistance to systolic flow and reducing the risk of systolic anterior motion. The blue arrows represent chordal tension, differing in thickness to represent the exertional force on the chords (colored orange). Note the chords are depicted ‘wavily’ in (a) to emphasize reduced chordal tension.

Fig. 3

Dynamics of the mitral valve complex during diastole and systole, including the commissural leaflets.

Fig. 4

(a) Leaflet peeling; (b) posterior mitral leaflet fenestration and chordal resection.