Chordal “translocation” for functional mitral regurgitation with severe valve tenting: An effort to preserve left ventricular structure and function

ObjectiveThe chordal cutting method is performed for mitral valve tenting in functional mitral regurgitation, such as ischemic mitral regurgitation. However, the method may interfere with the mitral valvular–ventricular continuity. To maintain the continuity and the natural force direction between the papillary muscles and the mitral annulus after chordal cutting, we developed “translocation” of the secondary chordae tendineae.MethodsSix mongrel dogs had sonomicrometry crystal markers implanted in the left ventricle, mitral annulus, and papillary muscle tips. After the secondary chordae tendineae of the anterior mitral leaflet from each papillary muscle were resected, each papillary muscle tip was connected to the mid-anterior mitral annulus with 4-0 polypropylene sutures, and then the sutures were taken out of the left atrium to control the chordal tension. The condition under which the artificial chordae were released was defined as “redundant.” The chordal tension of 15 g of weight was defined as “taut,” whereas the tension for 2-mm chordal shortening after “taut” was defined as “tight.” After the dogs were weaned from cardiopulmonary bypass, hemodynamic and 3-dimensional data were acquired under the condition of “redundant,” and then “taut,” “tight,” and “redundant.”ResultsEnd-systolic elastance increased from 1.81 ± 0.24 mm Hg/mL to 2.69 ± 0.89 mm Hg/mL (P = .015) between “redundant” and “taut,” and this was maintained between “taut” and “tight.” However, preload recruitable stroke work increased from 41.3 ± 12.0 mm Hg to 58.1 ± 19.7 mm Hg (P = .005) between “redundant” and “taut,” and was reduced to 51.7 ± 22.9 mm Hg (P = .037) between “taut” and “tight.”Conclusion“Translocation” of the secondary chordae tendineae after chordal cutting improved left ventricular systolic function compared with simple chordal cutting.