scholarly journals Understanding TAVR device expansion as it relates to morphology of the bicuspid aortic valve: A simulation study

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251579
Author(s):  
Jonathan Kusner ◽  
Giulia Luraghi ◽  
Farhan Khodaee ◽  
José Félix Rodriguez Matas ◽  
Francesco Migliavacca ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Bicuspid Aortic Valve ◽  
Free Edge ◽  
Von Mises Stress ◽  
Patient Specific ◽  
Aortic Valves ◽  
Transcatheter Aortic Valve ◽  
Element Simulation ◽  
Von Mises ◽  
Improve Device

The bicuspid aortic valve (BAV) is a common and heterogeneous congenital heart abnormality that is often complicated by aortic stenosis. Although initially developed for tricuspid aortic valves (TAV), transcatheter aortic valve replacement (TAVR) devices are increasingly applied to the treatment of BAV stenosis. It is known that patient-device relationship between TAVR and BAV are not equivalent to those observed in TAV but the nature of these differences are not well understood. We sought to better understand the patient-device relationships between TAVR devices and the two most common morphologies of BAV. We performed finite element simulation of TAVR deployment into three cases of idealized aortic anatomies (TAV, Sievers 0 BAV, Sievers 1 BAV), derived from patient-specific measurements. Valve leaflet von Mises stress at the aortic commissures differed by valve configuration over a ten-fold range (TAV: 0.55 MPa, Sievers 0: 6.64 MPa, and Sievers 1: 4.19 MPa). First principle stress on the aortic wall was greater in Sievers 1 (0.316 MPa) and Sievers 0 BAV (0.137 MPa) compared to TAV (0.056 MPa). TAVR placement in Sievers 1 BAV demonstrated significant device asymmetric alignment, with 1.09 mm of displacement between the center of the device measured at the annulus and at the leaflet free edge. This orifice displacement was marginal in TAV (0.33 mm) and even lower in Sievers 0 BAV (0.23 mm). BAV TAVR, depending on the subtype involved, may encounter disparate combinations of device under expansion and asymmetry compared to TAV deployment. Understanding the impacts of BAV morphology on patient-device relationships can help improve device selection, patient eligibility, and the overall safety of TAVR in BAV.

scholarly journals A retrospective analysis of mitral valve pathology in the setting of bicuspid aortic valves

2017 ◽  
Vol 4 (2) ◽  
pp. 21-28 ◽  
Author(s):  
Annari van Rensburg ◽  
Philip Herbst ◽  
Anton Doubell
Keyword(s):  
Mitral Valve ◽  
Aortic Valve ◽  
Retrospective Analysis ◽  
Bicuspid Aortic Valve ◽  
Valve Leaflet ◽  
Aortic Valves ◽  
Mitral Valve Leaflet ◽  
Therapeutic Implications ◽  
Transcatheter Aortic Valve ◽  
Bicuspid Aortic Valves

The therapeutic implications of bicuspid aortic valve associations have come under scrutiny in the transcatheter aortic valve implantation era. We evaluate the spectrum of mitral valve disease in patients with bicuspid aortic valves to determine the need for closer echocardiographic scrutiny/follow-up of the mitral valve. A retrospective analysis of echocardiograms done at a referral hospital over five years was conducted in patients with bicuspid aortic valves with special attention to congenital abnormalities of the mitral valve. One hundred and forty patients with a bicuspid aortic valve were included. A congenital mitral valve abnormality was present in eight (5.7%, P = 0.01) with a parachute mitral valve in four (2.8%), an accessory mitral valve leaflet in one (0.7%), mitral valve prolapse in one, a cleft in one and the novel finding of a trileaflet mitral valve in one. Minor abnormalities included an elongated anterior mitral valve leaflet (P < 0.001), the increased incidence of physiological mitral regurgitation (P < 0.001), abnormal papillary muscles (P = 0.002) and an additional chord or tendon in the left ventricle cavity (P = 0.007). Mitral valve abnormalities occur more commonly in patients with bicuspid aortic valves than matched healthy individuals. The study confirms that abnormalities in these patients extend beyond the aorta. These abnormalities did not have a significant functional effect.

scholarly journals Sealing Behavior in Transcatheter Bicuspid and Tricuspid Aortic Valves Replacement Through Patient-Specific Computational Modeling

2021 ◽  
Vol 8 ◽  
Author(s):  
Xianbao Liu ◽  
Jiaqi Fan ◽  
Peter Mortier ◽  
Yuxin He ◽  
Qifeng Zhu ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Aortic Valve ◽  
Computational Modeling ◽  
Maximum Diameter ◽  
Patient Specific ◽  
Aortic Valves ◽  
Minimum Diameter ◽  
Transcatheter Aortic Valve ◽  
Patient Interaction ◽  
Transcatheter Heart Valve

Background: Patient-specific computer simulation of transcatheter aortic valve replacement (TAVR) can provide unique insights in device-patient interaction.Aims: This study was to compare transcatheter aortic valve sealing behavior in patients with bicuspid aortic valves (BAV) and tricuspid aortic valves (TAV) through patient-specific computational modeling.Methods: Patient-specific computer simulation was retrospectively performed with FEops HEARTguide for TAVR patients. Simulation output was compared with postprocedural computed tomography and echocardiography to validate the accuracy. Skirt malapposition was defined by a distance larger than 1 mm based on the predicted device-patient interaction by quantifying the distance between the transcatheter heart valve (THV) skirt and the surrounding anatomical regions.Results: In total, 43 patients were included in the study. Predicted and observed THV frame deformation showed good correlation (R2 ≥ 0.90) for all analyzed measurements (maximum diameter, minimum diameter, area, and perimeter). The amount of predicted THV skirt malapposition was strongly linked with the echocardiographic grading of paravalvular leakage (PVL). More THV skirt malapposition was observed for BAV cases when compared to TAV cases (22.7 vs. 15.5%, p &lt; 0.05). A detailed analysis of skirt malapposition showed a higher degree of malapposition in the interleaflet triangles section for BAV cases as compared to TAV patients (11.1 vs. 5.8%, p &lt; 0.05).Conclusions: Patient-specific computer simulation of TAVR can accurately predict the behavior of the Venus A-valve. BAV patients are associated with more malapposition of the THV skirt as compared to TAV patients, and this is mainly driven by more malapposition in the interleaflet triangle region.

INVESTIGATION OF LEAFLET GEOMETRY IN A PERCUTANEOUS AORTIC VALVE WITH THE USE OF FLUID-STRUCTURE INTERACTION SIMULATION

2012 ◽  
Vol 12 (01) ◽  
pp. 1250003 ◽  
Author(s):  
K. H. J. VAN ASWEGEN ◽  
A. N. SMUTS ◽  
C. SCHEFFER ◽  
H. S. VH. WEICH ◽  
A. F. DOUBELL
Keyword(s):  
Aortic Valve ◽  
Fluid Structure Interaction ◽  
Von Mises Stress ◽  
Aortic Valves ◽  
Native Valve ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Prosthetic Valves ◽  
Significant Difference ◽  
Von Mises

Prosthetic aortic valves have been used for the replacement of dysfunctional native aortic valves in humans for more than fifty years. Current prosthetic valves have significant limitations and the development of improved aortic valve prostheses remains an important research focus area. This paper investigates one of the newer additions to the family of replacement valves, namely the stented percutaneous valve. An important design aspect of stented percutaneous valves, is the configuration of the leaflet's attachment to the surrounding stent. There are essentially two possible configurations: The first method is attaching the leaflets in a straight configuration, and the second method is to attach the leaflets in a curved configuration. Finite element models of both configurations were created, and the behavior of these configurations was then studied using a fluid-structure interaction (FSI) simulation. The FSI simulation was validated by means of comparing simulation results to actual measurements from a pulse duplicator using prototype valves of both configurations. The FSI results showed no significant difference between the valves' opening and closing behaviors. The von Mises stress distributions proved to be the largest differentiating and decisive factor between the two valves. The FSI simulations did however show that the leaflets that are attached in the straight configuration form folds that resembles that of the curved configuration as well as the native valve, but to a larger scale. The effect that these folds might have on valve tissue fatigue leaves room for future investigation.

Patient-Specific Valve Dynamics Using 3D Fluid-Structure Interaction Modeling: Comparison Between Bicuspid and Tricuspid Aortic Valves

2013 ◽  
Author(s):  
V. Govindarajan ◽  
J. Mousel ◽  
S. C. Vigmostad ◽  
H. S. Udaykumar ◽  
M. M. Levack ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Bicuspid Aortic Valve ◽  
Fluid Structure Interaction ◽  
Geometric Distortion ◽  
Patient Specific ◽  
Endothelial Lining ◽  
Aortic Valves ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Opening Phase

Aortic valve diseases such as congenital bicuspid aortic valve (BAV) and progressive calcification in tricuspid valves affect the hemodynamics in the aortic arch. In addition to leaflet calcification, BAVs are associated with other ailments such as aortic coarctation, aneurysm and dissection [1]. It has also been observed that progressive calcification is accelerated in the case of BAVs compared to normal tricuspid valves. While it is not yet known whether the geometric distortion in BAVs is the main cause of calcification [2] in these valves, the distortion in the leaflets may give rise to altered stresses during the deformation processes which might play a role in accelerating the calcification process in BAVs. In addition, the altered flow caused by the change in geometry could alter the local fluid stresses during the opening phase, which might affect the endothelial lining of the aortic wall. Analyzing and comparing BAV and tricuspid aortic valves as a fluid-structure interaction problem will help determine the stress distribution on the leaflets during opening phase, and enable the examination of altered flow dynamics in the ascending aorta. In this study, the opening phase of a patient-specific bicuspid aortic valve is analyzed at physiological conditions and compared with the opening phase of a tricuspid aortic valve.

scholarly journals Patient-specific Computer Simulation: An Emerging Technology for Guiding the Transcatheter Treatment of Patients with Bicuspid Aortic Valve

2021 ◽  
Vol 16 ◽  
Author(s):  
Cameron Dowling ◽  
Robert Gooley ◽  
Liam McCormick ◽  
Sami Firoozi ◽  
Stephen J Brecker
Keyword(s):  
Computer Simulation ◽  
Aortic Valve ◽  
Clinical Outcomes ◽  
Bicuspid Aortic Valve ◽  
Patient Specific ◽  
Transcatheter Aortic Valve ◽  
Anatomical Basis ◽  
Transcatheter Heart Valve ◽  
Risk Patients ◽  
Valve Implantation

Transcatheter aortic valve implantation (TAVI) is increasingly being used to treat younger, lower-risk patients, many of whom have bicuspid aortic valve (BAV). As TAVI begins to enter these younger patient cohorts, it is critical that clinical outcomes from TAVI in BAV are matched to those achieved by surgery. Therefore, the identification of patients who, on an anatomical basis, may not be suitable for TAVI, would be desirable. Furthermore, clinical outcomes of TAVI in BAV might be improved through improved transcatheter heart valve sizing and positioning. One potential solution to these challenges is patient-specific computer simulation. This review presents the methodology and clinical evidence surrounding patient-specific computer simulation of TAVI in BAV.

scholarly journals Incomplete expansion of transcatheter aortic valves is associated with propensity for valve thrombosis

2019 ◽  
Vol 30 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Farhan Khodaee ◽  
Mohammed Barakat ◽  
Mostafa Abbasi ◽  
Danny Dvir ◽  
Ali N Azadani
Keyword(s):  
Aortic Valve ◽  
Aortic Valve Replacement ◽  
Valve Replacement ◽  
Platelet Activation ◽  
Residence Time ◽  
Transcatheter Aortic Valve Replacement ◽  
Blood Stasis ◽  
Patient Specific ◽  
Aortic Valves ◽  
Transcatheter Aortic Valve

Abstract OBJECTIVES Clinical and subclinical leaflet thromboses are increasingly recognized complications following transcatheter aortic valve replacement. Identification of the risk factors is important to mitigate the occurrence of leaflet thrombosis in transcatheter aortic valves (TAVs) and ensure their long-term function. The goal of this study was to determine the effect of incomplete expansion of TAVs on the likelihood of leaflet thrombosis following transcatheter aortic valve replacement. METHODS Using experimental and computational methods, 3-dimensional unsteady flow fields of 26-mm SAPIEN 3 valves expanded to 3 different diameters (i.e. 26.0 mm, 23.4 mm and 20.8 mm) were determined in patient-specific geometries. The diameters corresponded to 100%, 90% and 80% stent expansion, respectively. To address the potential difference in the likelihood of leaflet thrombosis, blood residence time (i.e. stasis) and viscous shear stress on the surface of TAV leaflets were quantified and compared. RESULTS The results indicated that TAV underexpansion increased blood stasis on the TAV leaflets. Blood residence time on the surface of the leaflets after 80% and 90% TAV expansion on average was 9.4% and 4.1% more than that of the fully expanded TAV, respectively. In addition, areas of blood stasis time of more than 0.5 s, which are highly prone to platelet activation, increased linearly as the degree of TAV underexpansion increased. CONCLUSIONS Incomplete expansion of TAVs increases blood stasis on the surface of TAV leaflets. Regions of blood stasis promote platelet activation and thrombotic events. TAV underexpansion can therefore increase the risk of leaflet thrombosis in patients with transcatheter aortic valve replacement.

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