Selectively Compliant Annuloplasty Ring to Enable Annular Dynamics in Mitral Valve Repair Evaluated by In-Vitro Stereovision

Abstract Mitral valve (MV) annular dynamics are critical to the long term efficacy of MV repair. Today’s annuloplasty rings, used to restore MV function, impose significant constraints on the motion profile of the MV annulus. We present a selectively compliant ring that provides sufficient stiffness to stabilize a diseased annulus while allowing physiological annular dynamics. Ring design is informed by a finite element analysis and experimentally evaluated with in-vitro stereophotogrammetry. We compare the ring dynamics to commercially available semi-rigid rings as well as values found in literature for healthy annuli. The results demonstrate that motion of the selectively compliant ring is significantly closer to that of a healthy annulus based on standard metrics that define MV annular movement. Specifically, the metrics for the new ring compare to those in literature as follows: change in orifice area 12.5 ± 3% vs.10 ± 2%; change in anterior-posterior diam. 5.4 ± 0.3% vs. 7 ± 1%; change in inter-commissural diam. 6.6 ± 1.3% vs. 5 ± 1%.

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In Silico Modelling of Aortic Valve Implants – Predicting In Vitro Performance using Finite Element Analysis

10.31224/osf.io/nzqu2 ◽

2021 ◽

Author(s):

Robert Whiting ◽

Elizabeth Sander ◽

Claire Conway ◽

Ted J Vaughan

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Aortic Valve ◽

In Silico ◽

Dynamic Parameters ◽

Valve Design ◽

Element Analysis ◽

Orifice Area ◽

In Silico Modelling

The competing structural and hemodynamic considerations in valve design generally require a large amount of in vitro hydrodynamic and durability testing during development, often resulting in inefficient “trial-and-error” prototyping. While in silico modelling through Finite Element Analysis (FEA) has been widely used to inform valve design by optimizing structural performance, few studies have exploited the potential insight FEA could provide into critical hemodynamic performance characteristics of the valve. The objective of this study is to demonstrate the potential of FEA to predict the hydrodynamic performance of aortic valve implants obtained during development through in vitro testing. Several variations of surgical tri-leaflet aortic valves were de-signed and manufactured using a synthetic polymer and hydrodynamic testing carried out using a pulsatile flow rig according to ISO 5840, with bulk hydro-dynamic parameters measured. In silico models were developed in tandem and suitable surrogate measures were investigated as predictors of the hydro-dynamic parameters. Through regression analysis, the in silico parameters of leaflet coaptation area, geometric orifice area and opening pressure were found to be suitable indicators of experimental in vitro hydrodynamic param-eters: regurgitant fraction, effective orifice area and transvalvular pressure drop performance, respectively.

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Finite element analysis to model complex mitral valve repair

Asian Cardiovascular and Thoracic Annals ◽

10.1177/0218492314539334 ◽

2014 ◽

Vol 24 (1) ◽

pp. 60-62 ◽

Cited By ~ 4

Author(s):

Michel Labrosse ◽

Thierry Mesana ◽

Ian Baxter ◽

Vincent Chan

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Mitral Valve ◽

Mitral Valve Repair ◽

Valve Repair ◽

Element Analysis ◽

Model Complex

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Material properties of the ovine mitral valve anterior leaflet in vivo from inverse finite element analysis

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00284.2008 ◽

2008 ◽

Vol 295 (3) ◽

pp. H1141-H1149 ◽

Cited By ~ 61

Author(s):

Gaurav Krishnamurthy ◽

Daniel B. Ennis ◽

Akinobu Itoh ◽

Wolfgang Bothe ◽

Julia C. Swanson ◽

...

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Mitral Valve ◽

Material Properties ◽

Element Model ◽

Left Ventricular ◽

Element Analysis ◽

Inverse Finite Element Analysis

We measured leaflet displacements and used inverse finite-element analysis to define, for the first time, the material properties of mitral valve (MV) leaflets in vivo. Sixteen miniature radiopaque markers were sewn to the MV annulus, 16 to the anterior MV leaflet, and 1 on each papillary muscle tip in 17 sheep. Four-dimensional coordinates were obtained from biplane videofluoroscopic marker images (60 frames/s) during three complete cardiac cycles. A finite-element model of the anterior MV leaflet was developed using marker coordinates at the end of isovolumic relaxation (IVR; when the pressure difference across the valve is ∼0), as the minimum stress reference state. Leaflet displacements were simulated during IVR using measured left ventricular and atrial pressures. The leaflet shear modulus ( Gcirc-rad) and elastic moduli in both the commisure-commisure ( Ecirc) and radial ( Erad) directions were obtained using the method of feasible directions to minimize the difference between simulated and measured displacements. Group mean (±SD) values (17 animals, 3 heartbeats each, i.e., 51 cardiac cycles) were as follows: Gcirc-rad= 121 ± 22 N/mm2, Ecirc= 43 ± 18 N/mm2, and Erad= 11 ± 3 N/mm2( Ecirc> Erad, P < 0.01). These values, much greater than those previously reported from in vitro studies, may result from activated neurally controlled contractile tissue within the leaflet that is inactive in excised tissues. This could have important implications, not only to our understanding of mitral valve physiology in the beating heart but for providing additional information to aid the development of more durable tissue-engineered bioprosthetic valves.

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Standardized Strategy and Long-Term Surgical Outcome of Mitral Valve Repair in Congenital Mitral Stenosis

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-0035-1544529 ◽

2015 ◽

Vol 63 (S 01) ◽

Author(s):

E. Delmo Walter ◽

A. Amiri ◽

R. Hetzer

Keyword(s):

Mitral Valve ◽

Mitral Valve Repair ◽

Surgical Outcome ◽

Mitral Stenosis ◽

Valve Repair ◽

Congenital Mitral Stenosis

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Predictors of outcomes in patients with mitral regurgitation undergoing percutaneous valve repair

European Heart Journal ◽

10.1093/ehjci/ehaa946.2008 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

A Polimeni

Keyword(s):

Heart Failure ◽

Mitral Valve ◽

Mitral Regurgitation ◽

Primary Endpoint ◽

Cardiovascular Death ◽

Volume Index ◽

Valve Repair ◽

Percutaneous Valve Repair ◽

Percutaneous Valve

Abstract Background Percutaneous mitral valve repairs has been increasingly performed worldwide. The MITRA-UMG registry provides a snapshot of a real-world clinical data and outcomes. Purpose We sought to investigate predictors of clinical outcomes in patients with mitral regurgitation undergoing percutaneous valve repair. Methods The MITRA-UMG registry retrospectively collected data from consecutive patients with symptomatic moderate-to-severe or severe MR underwent MitraClip implantation. The primary endpoint of interest was the composite of cardiovascular death or rehospitalization for HF. Results Between March 2012 and July 2018, a total of 133 consecutive patients admitted to our institution were included. Acute procedural success was obtained in 95.4% of patients, with no intraprocedural death. The composite primary endpoint of cardiovascular death or rehospitalization for heart failure was met in 50 patients (38%) with cumulative incidences of 7%, 25%, at 30 days and 1 year, respectively. In the Cox multivariate model, NYHA functional class IV, left ventricular end-diastolic volume index (LVEDVi), Euroscore II, independently increased the risk of the primary endpoint at long-term follow-up. At Kaplan-Meier analysis, a LVEDVi >92 ml/m2 was associated with an increased incidence of the primary endpoint. Conclusions In searching the ideal phenotype of patients who benefit most of percutaneous mitral valve repair, those presenting with severely dilated ventricles (LVEDVi >92 ml/m2), high operative risk (EUROSCORE II >7%) or advanced heart failure symptoms (NYHA IV) at baseline carried the worst prognosis at long-term. Funding Acknowledgement Type of funding source: None

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Long-Term Clinical Outcome in Elderly Patients Undergoing Mitral Valve Repair

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-0040-1716324 ◽

2020 ◽

Author(s):

Julia Götte ◽

Armin Zittermann ◽

Kavous Hakim-Meibodi ◽

Masatoshi Hata ◽

Rene Schramm ◽

...

Keyword(s):

Mitral Valve ◽

General Population ◽

Elderly Patients ◽

Cox Regression ◽

Functional Class ◽

Tricuspid Valve Repair ◽

Valve Repair ◽

Cox Regression Analysis

Abstract Background Long-term data on patients over 75 years undergoing mitral valve (MV) repair are scarce. At our high-volume institution, we, therefore, aimed to evaluate mortality, stroke risk, and reoperation rates in these patients. Methods We investigated clinical outcomes in 372 patients undergoing MV repair with (n = 115) or without (n = 257) tricuspid valve repair. The primary endpoint was the probability of survival up to a maximum follow-up of 9 years. Secondary clinical endpoints were stroke and reoperation of the MV during follow-up. Univariate and multivariable Cox regression analysis was performed to assess independent predictors of mortality. Mortality was also compared with the age- and sex-adjusted general population. Results During a median follow-up period of 37 months (range: 0.1–108 months), 90 patients died. The following parameters were independently associated with mortality: double valve repair (hazard ratio, confidence interval [HR, 95% CI]: 2.15, 1.37–3.36), advanced age (HR: 1.07, CI: 1.01–1.14 per year), diabetes (HR: 1.97, CI: 1.13–3.43), preoperative New York Heart Association (NYHA) functional class (HR: 1.41, CI: 1.01–1.97 per class), and operative creatininemax levels (HR: 1.32, CI: 1.13–1.55 per mg/dL). The risk of stroke in the isolated MV and double valve repair groups at postoperative year 5 was 5.0 and 4.1%, respectively (p = 0.65). The corresponding values for the risk of reoperation were 4.0 and 7.0%, respectively (p = 0.36). Nine-year survival was comparable with the general population (53.2 vs. 53.1%). Conclusion Various independent risk factors for mortality in elderly MV repair patients could be identified, but overall survival rates were similar to those of the general population. Consequently, our data indicates that repairing the MV in elderly patients represents a suitable and safe surgical approach.

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