Figure 2 - available from: Scientific Reports
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Surgical setup during the measuring phase. During this step of the protocol, the chordae were fixed to the measurement device that was brought close to the patient. While puling on the first chordae a pressure curve can be observed on the display (yellow curve).
Source publication
In this paper, we propose a very innovative designed system that enables optimal length adjustment during transapical neochordae implantation for mitral valve repair, increasing accuracy and reproducibility of neochordae length adjustment. Also, such a new device allowed real-time measurement and recording of chordae tension, producing original phy...
Context in source publication
Context 1
... distal part of implanted neochordae oscillates with mitral movements. The length of the neochordae has to be precisely adapted to obtain a normal coaptation to treat the regurgitation. The evaluation of the tension directly interfered at that step ("Surgical Step 3"). The device is brought closer to the patient only during the measurement phase (Fig. 2). The neochordae are connected to the measuring device through "crocodile" clips (e.g. machine-patient interface, "testing Step 3A", Fig. 3). In the first generation of the platform, the attachment part was not sterile. The sterile sutures, however, were sufficiently long (120 mm) to allow placement of the unsterile platform far from ...
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Background:
Limited information has been reported regarding the impact of percutaneous mitral valve repair (PMVR) on ventricular arrhythmic (VA) burden. The aim of this study was to address the incidence of VA and appropriate antitachycardia implantable cardiac defibrillator (ICD) therapies before and after PMVR.
Methods:
We retrospectively anal...
Citations
... Currently, choosing the treatment plan that provides the greatest benefit to the patient is one of the biggest clinical challenges for cardiologists and cardiac surgeons [8]. Determining optimal neochord length is one of the main issues that cardiac surgeons must address in MV repair procedures [9], and it is particularly challenging to define this length due to a general lack of accurate anatomical information from standard diagnostic imaging, which includes only the en-face view of the mitral valve. Chordae tendineae length measurements are required for mitral valve procedures involving the implantation of artificial chordae [10]. ...
... By combining both the en-face and transgastric views, we can maintain optimal imaging for both structures in a single compounded volume. Integrated leaflet and chordae geometry in a single volume will greatly improve the cardiac surgeons' ability to accurately measure the length of individual chordae (a crucial factor in neochordae repair techniques [9]) and plan their repair strategy. ...
Three-dimensional ultrasound mosaicing can increase image quality and expand the field of view. However, limited work has been done applying these compounded approaches for cardiac procedures focused on the mitral valve. For procedures targeting the mitral valve, transesophageal echocardiography (TEE) is the primary imaging modality used as it provides clear 3D images of the valve and surrounding tissues. However, TEE suffers from image artefacts and signal dropout, particularly for structures lying below the valve, including chordae tendineae, making it necessary to acquire alternative echo views to visualize these structures. Due to the limited field of view obtainable, the entire ventricle cannot be directly visualized in sufficient detail from a single image acquisition in 3D. We propose applying an image compounding technique to TEE volumes acquired from a mid-esophageal position and several transgastric positions in order to reconstruct a high-detail volume of the mitral valve and sub-valvular structures. This compounding technique utilizes both fully and semi-simultaneous group-wise registration to align the multiple 3D volumes, followed by a weighted intensity compounding step based on the monogenic signal. This compounding technique is validated using images acquired from two excised porcine mitral valve units and three patient data sets. We demonstrate that this compounding technique accurately captures the physical structures present, including the mitral valve, chordae tendineae and papillary muscles. The chordae length measurement error between the compounded ultrasound and ground-truth CT for two porcine valves is reported as 0.7 ± 0.6 mm and 0.6 ± 0.6 mm.
... The materials reported in this research might have promising potential applications, involving in the development of biosensor device for cardiac surgery of mitral regurgitation (MRe). It has been well known that MRe is a major public health problem with a global prevalence of 9.3% in individuals over 75 years of age [73]. It is defined as reversed blood flow of part of the left ventricle load toward the left atrium at every cardiac systole, resulting in an overload in the left atrium and pulmonary circulation. ...
Piezoelectric ZnO-based composites have been explored as a flexible and compact sensor for the implantable biomedical systems used in cardio surgery. In this work, a progressive development route was investigated to enhance the performance of piezoelectric composites incorporated with different shape, concentration and connectivity of ZnO fillers. ZnO microrods (MRs) have been successfully synthesized homogeneously in aqueous solution using a novel process-based on chemical bath deposition (CBD) method. The morphological analysis along with Raman scattering and cathodoluminescence spectroscopy of ZnO MRs confirm their high crystalline quality, their orientation along the polar c-axis and the presence of hydrogen-related defects acting as shallow donors in their center. The experimental characterizations highlight that ZnO MR-based composites, with a higher aspect ratio (AR), lead to a significant improvement in the mechanical, dielectric and piezoelectric properties as opposed to the ZnO microparticles (MP) counterparts. The dielectrophoretic (DEP) process is then subjected to both ZnO MP- and MR-based composites, whose performance is expected to be improved as compared to the randomly dispersed composites, thanks to the creation of chain-like structures along the electric field direction. Furthermore, a numerical simulation using COMSOL software is developed to evaluate the influence of the material structuration as well as the filler’s shape on the electric field distribution within different phases (filler, matrix and interface) of the composites. Finally, the aligned MR piezoelectric composites are revealed to be high potential in the development of innovative compact and biocompatible force-sensing devices. Such a technological breakthrough allows the achievement of a real-time precise characterization of mitral valve (MV) coaptation to assist surgeons during MV repair surgery.
... The localization of fibrosis within the myocardium suggests a role for increased mechanical stress through the chordae in MVP (Figure 9), consistent with recent reports. [58][59][60] Support for increased mechanical stress is also based on a recent study that showed primary chordal forces, and therefore the force on the attached papillary muscles, are 5-fold higher in bileaflet prolapse compared with postmitral valve repair. 61 Although our current findings and previous reports strongly support primary cilia defects in the cause of MVP, it is likely that MVP and MVP-associated LV remodeling do not solely stem from defects in the cilia pathway but instead through alternate independent mechanisms. ...
Background
Mitral valve prolapse (MVP) is one of the most common forms of cardiac valve disease and affects 2% to 3% of the population. Previous imaging reports have indicated that myocardial fibrosis is common in MVP and described its association with sudden cardiac death. These data combined with evidence for postrepair ventricular dysfunction in surgical patients with MVP support a link between fibrosis and MVP.
Methods and Results
We performed histopathologic analysis of left ventricular (LV) biopsies from peripapillary regions, inferobasal LV wall and apex on surgical patients with MVP, as well as in a mouse model of human MVP ( Dzip1 S14R /+ ). Tension‐dependent molecular pathways were subsequently assessed using both computational modeling and cyclical stretch of primary human cardiac fibroblasts in vitro. Histopathology of LV biopsies revealed regionalized fibrosis in the peripapillary myocardium that correlated with increased macrophages and myofibroblasts. The MVP mouse model exhibited similar regional increases in collagen deposition that progress over time. As observed in the patient biopsies, increased macrophages and myofibroblasts were observed in fibrotic areas within the murine heart. Computational modeling revealed tension‐dependent profibrotic cellular and molecular responses consistent with fibrosis locations related to valve‐induced stress. These simulations also identified mechanosensing primary cilia as involved in profibrotic pathways, which was validated in vitro and in human biopsies. Finally, in vitro stretching of primary human cardiac fibroblasts showed that stretch directly activates profibrotic pathways and increases extracellular matrix protein production.
Conclusions
The presence of prominent regional LV fibrosis in patients and mice with MVP supports a relationship between MVP and progressive damaging effects on LV structure before overt alterations in cardiac function. The regionalized molecular and cellular changes suggest a reactive response of the papillary and inferobasal myocardium to increased chordal tension from a prolapsing valve. These studies raise the question whether surgical intervention on patients with MVP should occur earlier than indicated by current guidelines to prevent advanced LV fibrosis and potentially reduce residual risk of LV dysfunction and sudden cardiac death.
Objective
To evaluate mid-term outcomes of transventricular mitral valve (MV) repair and its association with initial anatomy of the MV.
Methods
This non-randomized observational study included 88 patients (mean age 60 years; 69% men) who underwent transventricular MV repair for severe degenerative mitral regurgitation (MR) between 2011 and 2017. MV function was assessed by echocardiography at 1, 6 months and annually after the procedure. According to the location of MV pathology, all patients were stratified into four anatomical types (A, B, C, and D). Results were assessed using Kaplan-Meier method, mixed-effects continuation ratio model, and multivariable Cox regression.
Results
Median follow-up of 42 months (IQR 27-55) was complete for 83 patients (94.3%). There were 3 late deaths: two cardiac and one non-cardiac. Recurrent MR>2+ was observed in 29 patients (33%), 18 patients (20.5%) underwent repeat surgery. Device success was 82% in type A patients at 6 months and thereafter; 87%, 85%, and 75% at 6, 12, and 36 months in type B; 53% at 1 month and 20% at 24 months in type C group. Probability of postoperative MR progression was higher in patients with greater preoperative LVEDD, type B, and type C pathology (p<0.05). Risk factors of MR recurrence included increased LV size (HR 1.11, 95% CI 1.04-1.20, p=0.001) and type C pathology (HR 5.99, 95% CI 1.87-19.21, p=0.003).
Conclusions
Initial acceptable MR reduction following transventricular MV repair of isolated P2 prolapse was possible but found durable in only 82% at three years. Higher risk of MR recurrence occurred with complex degenerative pathology.
Résumé
Malgré l’importante prévalence de l’insuffisance mitrale primaire, les techniques et les résultats du traitement chirurgical restent hétérogènes. Le geste opératoire est essentiellement guidé par une évaluation morphologique (échocardiographique préopératoire et visuelle peropératoire) et le succès de la réparation valvulaire repose essentiellement sur l’expertise du chirurgien. Certaines évolutions technologiques récentes nous permettent aujourd’hui de concevoir des outils innovants dédiés permettant la mesure de paramètres physiques au cours de ces chirurgies. Au cours des procédures de réparation mitrale par implantation de néocordages par voie transapicale, à cœur battant et sans circulation extracorporelle, la tension exercée sur les néocordages implantés peut être mesurée. En plus d’améliorer notre compréhension de la physiopathologie mitrale, cette mesure permet d’adapter la traction afin d’obtenir une « réparation à bas-stress », faisant espérer des résultats à long terme optimaux. Une cartographie bidimensionnelle des forces de coaptation mitrale pourrait être réalisée lors d’une chirurgie mitrale conventionnelle (à « cœur ouvert » et sous circulation extracorporelle). Celle-ci pourrait permettre de mesurer de façon précise et en temps réel la surface de coaptation et d’évaluer la répartition des forces de coaptation valvulaire. Ces deux exemples illustrent le concept de chirurgies valvulaires guidées par des mesures physiques, en plus des mesures morphologiques habituelles. Néanmoins, si le concept de « réparation à bas-stress » est intuitivement attrayant, l’intérêt pronostique lié à l’utilisation de ces outils doit être évalué au travers d’études cliniques avec suivi prospectif à long terme.
