Biomechanical analysis of neochordal repair error from diastolic phase inversion of static left ventricular pressurization

Large Animal Translational Validation of 3 Mitral Valve Repair Operations for Mitral Regurgitation Using a Mitral Valve Prolapse Model: A Comprehensive In Vivo Biomechanical Engineering Analysis

“…This validated our previously reported ex vivo P2 MVP models in our 3-dimensional-printed left heart simulator. 39,40,[42][43][44] Similar to what we observed repeatedly in our ex vivo system, 39,40,[42][43][44] this in vivo ovine P2 MVP model was not only associated with significant MR confirmed by clinically relevant echocardiography data but also generated elevated native chordal forces in both primary and secondary chordae. We previously evaluated the biomechanics underlying several MV repair operations using the ex vivo left heart simulator and found that nonresectional repair techniques, particularly neochordal implantation repair, compared with resectional repair, were associated with less postrepair residual MR and lower chordal forces.…”

“…This validated our previously reported ex vivo P2 MVP models in our 3-dimensional-printed left heart simulator. 39,40,42–44 Similar to what we observed repeatedly in our ex vivo system, 39,40,42–44 this in vivo ovine P2 MVP model was not only associated with significant MR confirmed by clinically relevant echocardiography data but also generated elevated native chordal forces in both primary and secondary chordae.…”

Chordal force profile after neochordal repair of anterior mitral valve prolapse: An ex vivo study

“…Thus, competence testing may lead to an overestimation in neochord length constituting a mechanically deficient repair. 31 Therefore, moderate residual MR should be considered a failure of the procedure, whereas mild residual MR should be considered a failure associated with the valve. According to a report by Kim and colleagues, 9 patients with mild residual MR at discharge deteriorated relatively slowly, with 50% of patients progressing to moderate or greater MR over 5 years after repair.…”

Neochords: How long, how many, too many?

“…Specifically, when the ventricle is pressurized with saline during diastolic arrest, it is relatively distended compared with systole and the papillary muscles are farther away from the true plane of coaptation—a phenomenon called diastolic phase inversion ( Figure 3 ). 19 The surgical implications of this phenomenon are that the surgeon must avoid being misled by the slightly increased distance between the papillary muscles of a distended ventricle and the plane of coaptation. Keeping diastolic phase inversion in mind, the surgeon should secure the neochords at a slightly shorter length than suggested by the saline test when they are interrogating the coaptation of the repaired valve.…”

“…Keeping diastolic phase inversion in mind, the surgeon should secure the neochords at a slightly shorter length than suggested by the saline test when they are interrogating the coaptation of the repaired valve. 19 In addition to achieving a repair without leakage and SAM, a surgeon must be facile with the interpretation of intraoperative echocardiography and capable of extrapolating the expected shift in the zone of coaptation to account for positive remodeling of the left ventricular geometry following repair. Specifically, an apparently acceptable zone of coaptation at the time of surgery may eventually result in SAM if positive remodeling is not duly considered when sizing neochordae.…”