Adult: Mitral Valve: Evolving TechnologyNeochordal Goldilocks: Analyzing the biomechanics of neochord length on papillary muscle forces suggests higher tolerance to shorter neochordae
Graphical abstract
Section snippets
Ex Vivo Left Heart Modeling
MVs (n = 8) were explanted from healthy porcine hearts obtained from an abattoir and mounted in a left heart simulation flow loop system as previously described and validated (Figure 2, A).14,15,22, 23, 24, 25, 26, 27 The use of porcine cardiac tissue from an abattoir is exempt from committee approval, and all experiments were performed in accordance with institutional guidelines. Our left heart flow loop features a linear piston pump (Superpump, ViVitro Labs) used to generate physiologic
Results
Baseline hemodynamic performance reflected healthy functioning of the porcine MVs. Ventricular maximum pressures and transmitral mean systolic pressures were held consistent at 123.72 ± ± 0.69 mm Hg and 98.56 ± ± 0.51 mm Hg, respectively. Mitral regurgitant fraction was held to a low 2.81% ± 0.37%. The prolapse condition saw significant reductions in both pressure metrics, as valve competence deteriorated upon chordal rupture, with values of 111.67 ± 5.79 mm Hg (P < .01) and 86.99 ± 4.95 mm Hg (
Discussion
Leveraging advances in ex vivo heart simulation technology, we used high-resolution PM force sensors and a novel neochord lengthening system to biomechanically quantify the changes in forces for every millimeter of P2 primary neochord length change during simulated surgical MV repair. Our results provide new insights for better understanding the biomechanics of the surgical neochordal repair procedure, with relevant implications on optimizing repair performance. We aim to translate our ex vivo
Conclusions
Understanding the detailed biomechanics of neochordal repair and optimizing the procedure for greater reliability and durability are of utmost importance to improved patient health and safety. Our experiments indicate that millimeters of additional or reduced lengths of P2 primary neochordae can have substantial biomechanical impacts on the PM forces, which have been linked to poor clinical outcomes including fibrotic development and ventricular arrhythmias. These results indicate that surgeons
References (33)
- et al.
2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association task force on practice guidelines
J Am Coll Cardiol
(2014) - et al.
2017 AHA/ACC focused update of the 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association task force on clinical practice guidelines
J Am Coll Cardiol
(2017) - et al.
Chordal replacement with polytetrafluoroethylene sutures for mitral valve repair: a 25-year experience
J Thorac Cardiovasc Surg
(2013) - et al.
Biomechanical engineering analysis of commonly utilized mitral neochordae
JTCVS Open
(2021) - et al.
Beyond the 10-year horizon: mitral valve repair solely with chordal replacement and annuloplasty
Ann Thorac Surg
(2023) - et al.
Biomechanical analysis of neochordal repair error from diastolic phase inversion of static left ventricular pressurization
JTCVS Techniques
(2022) - et al.
Toward a new paradigm for the reconstruction of posterior leaflet prolapse: midterm results of the “respect rather than resect” approach
Ann Thorac Surg
(2008) - et al.
Papillary muscle traction in mitral valve prolapse: quantitation by two-dimensional echocardiography
J Am Coll Cardiol
(1992) - et al.
Ex vivo biomechanical study of apical versus papillary neochord anchoring for mitral regurgitation
Ann Thorac Surg
(2019) - et al.
Artificial papillary muscle device for off-pump transapical mitral valve repair
J Thorac Cardiovasc Surg
(2022)
Chordal force distribution determines systolic mitral leaflet configuration and severity of functional mitral regurgitation
J Am Coll Cardiol
Characterisation of the fatigue life, dynamic creep and modes of damage accumulation within mitral valve chordae tendineae
Acta Biomater
Short coaptation length is a predictor of recurrent mitral regurgitation after mitral valve plasty
Heart Lung Circ
Prevalence and clinical outcome of mitral-valve prolapse
N Engl J Med
Valve repair versus valve replacement for degenerative mitral valve disease
J Thorac Cardiovasc Surg
Mitral-valve repair versus replacement for severe ischemic mitral regurgitation
N Engl J Med
Cited by (2)
This work was supported by the National Institutes of Health (NIH F32 HL158151, Y.Z.; NIH R01-HL141917-04, R.A.L.; NIH R01 HL152155, Y.J.W.), the American Heart Association Postdoctoral Fellowship (A.V.K.), the Thoracic Surgery Foundation Resident Research Fellowship (Y.Z.), and the American Heart Association Transformational Project Award (R.A.L.).