Treatment of Tricuspid Regurgitation at Subvalvular Level: Hemodynamic and Morphological Assessment in Ex-Vivo Beating Heart Model

ABSTRACTBackground: Functional tricuspid regurgitation (FTR) treatment is challenging and most therapies targeting tricuspid valve (TV) annulus have shown limited durability with high rate of resid..

Transcatheter Edge-to-Edge Treatment of Functional Tricuspid Regurgitation in an Ex Vivo Pulsatile Heart Model

Although associated with left heart pathologies, functional tricuspid regurgitation (FTR) is often left untreated during left heart surgery. Hence, owing to its degenerative character, reoperation is often needed, encompassing an impressive (25% to 35%) mortality rate. Thus transcatheter approaches to FTR are raising great interest

Transfer Learning Methods as a New Approach in Computer Vision Tasks with Small Datasets

Deep learning methods, used in machine vision challenges, often face the problem of the amount and quality of data. To address this issue, we investigate the transfer learning method. In this study, we briefly describe the idea and introduce two main strategies of transfer learning. We also present the widely-used neural network models, that in recent years performed best in ImageNet classification challenges. Furthermore, we shortly describe three different experiments from computer vision field, that confirm the developed algorithms ability to classify images with overall accuracy 87.2-95%. Achieved numbers are state-of-the-art results in melanoma thickness prediction, anomaly detection and Clostridium di cile cytotoxicity classification problems

Leaflet kinematics after the Yacoub and Florida-sleeve operations: results of an in vitro study

The Florida-sleeve is a valve-sparing technique that causes minimal interference to leaflet kinematics and aortic root dynamism. The aim of this in vitro study was to evaluate the effects of the Florida-sleeve and Yacoub techniques on aortic leaflet kinematics

Long-arm Clip for Transcatheter Edge-to-Edge Treatment of Mitral and Tricuspid Regurgitation – Ex-Vivo Beating Heart Study

Background: A longer-arm clip design for transcatheter edge-to-edge repair of mitral and tricuspid valves could be beneficial in treating complex valve pathologies. Its hemodynamic effects and usability are unknown. This study aims to assess its new design in an ex-vivo beating heart model. Methods: The long-arm clip was implanted in porcine left (n = 14) and right (n = 6) hearts with induced degenerative mitral regurgitation and functional tricuspid regurgitation, respectively. Hemodynamic conditions were assessed at baseline, pathology and post-treatment. Usability and grasping quality were evaluated during simulated treatment. Results: Mitral valve treatment significantly increased cardiac output (p < 0.001) and decreased mean left atrial pressure during ventricular systole (p = 0.001) with respect to pathological conditions. Tricuspid treatment with grasping involving septal leaflet significantly increased cardiac output (posterior-septal grasping: p = 0.006; anterior-septal grasping: p = 0.04). There was no significant increase of transvalvular gradient pressure nor tissue damage. Conclusion: Long-arm clip treatment was feasible in porcine hearts, it effectively reduced regurgitation and did not significantly increase the transvalvular pressure gradient

Morphometric Characterization of an Ex Vivo Porcine Model of Functional Tricuspid Regurgitation

Emerging treatments for tricuspid valve (TV) regurgitation require realistic TV pathological models for preclinical testing. The aim of this work was to investigate structural features of fresh and defrosted porcine right-heart samples as models of mild and severe functional tricuspid regurgitation (FTR) condition in ex-vivo pulsatile flow platform. Ten fresh hearts were tested ex-vivo under steady and pulsatile flow in typical right-heart loading conditions. Hemodynamics and 3D echocardiographic imaging of TV and right ventricle (RV) were acquired. Hearts were then kept frozen for 14 days, defrosted, and tested again with the same protocol. Morphometric parameters of TV and RV were derived from 3D reconstructions based on echo data. Fresh samples showed a slightly dilated TV morphology, with coaptation gaps among the leaflets. Sample freezing induced worsening of TV insufficiency, with significant (p < 0.05) increases in annulus size (annulus area and perimeter 7.7-3.1% respectively) and dilation of RV (9.5%), which led to an increase in tenting volume (123.7%). These morphologic alterations reflected into a significant increment of regurgitation fraction (27%). Together, such results suggest that fresh porcine heart samples may be a reliable ex-vivo model of mild FTR condition, which can be enhanced through freezing/thawing treatment to model a severe pathological condition