Fluid Study of Transcatheter Aortic Valve Deployment Into Patients With Varying Coronary Ostia Position

2011 ◽  
Author(s):  
Eric Sirois ◽  
Qian Wang ◽  
Susheel Kodali ◽  
Wei Sun
Keyword(s):  
Aortic Valve ◽  
Aortic Root ◽  
Cfd Simulation ◽  
Patient Specific ◽  
Coronary Ostium ◽  
Case Scenario ◽  
Element Analysis ◽  
Worst Case ◽  
Transcatheter Aortic Valve ◽  
Coronary Ostia

Recently, minimally-invasive transcatheter aortic valve (TAV) replacement has emerged as a viable alternative to traditional open-chest heart valve replacement for high risk patients who otherwise have limited or no treatment options. Although significant experience with TAV procedures has been gained, various adverse effects have been observed after device implantation [1, 2]. One adverse event is the impairment of coronary artery flow. Because the TAV stent pushes the native leaflets towards the sinus of Valsalva during TAV deployment, the flow boundaries in the aortic root are consequently altered. A worst case scenario would be the occlusion of the coronary ostia. Reduced flow to the coronary arteries has also been observed for some patients following TAV intervention [3]. With IRB approval, we recently conducted a dimensional analysis of 3D aortic root geometries, reconstructed from 64-slice CT scans of 95 patients [4]. TAV-relevant dimensions were measured. The spatial distribution of the left coronary ostium was quantified (Fig. 1). In this study, we will construct a patient-specific aortic root model with varied coronary ostium locations as shown in Fig. 1, and perform a combined finite element analysis (FEA) and computational fluid dynamics (CFD) simulation to investigate hemodynamic environment changes that occur following TAV intervention.

scholarly journals Numerical Parametric Study of Paravalvular Leak Following a Transcatheter Aortic Valve Deployment Into a Patient-Specific Aortic Root

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Wenbin Mao ◽  
Qian Wang ◽  
Susheel Kodali ◽  
Wei Sun
Keyword(s):  
Aortic Valve ◽  
Computational Model ◽  
Aortic Root ◽  
Paravalvular Leak ◽  
Patient Specific ◽  
Fe Method ◽  
Transcatheter Aortic Valve ◽  
Operative Planning ◽  
The Difference ◽  
The Impact

Paravalvular leak (PVL) is a relatively frequent complication after transcatheter aortic valve replacement (TAVR) with increased mortality. Currently, there is no effective method to pre-operatively predict and prevent PVL. In this study, we developed a computational model to predict the severity of PVL after TAVR. Nonlinear finite element (FE) method was used to simulate a self-expandable CoreValve deployment into a patient-specific aortic root, specified with human material properties of aortic tissues. Subsequently, computational fluid dynamics (CFD) simulations were performed using the post-TAVR geometries from the FE simulation, and a parametric investigation of the impact of the transcatheter aortic valve (TAV) skirt shape, TAV orientation, and deployment height on PVL was conducted. The predicted PVL was in good agreement with the echocardiography data. Due to the scallop shape of CoreValve skirt, the difference of PVL due to TAV orientation can be as large as 40%. Although the stent thickness is small compared to the aortic annulus size, we found that inappropriate modeling of it can lead to an underestimation of PVL up to 10 ml/beat. Moreover, the deployment height could significantly alter the extent and the distribution of regurgitant jets, which results in a change of leaking volume up to 70%. Further investigation in a large cohort of patients is warranted to verify the accuracy of our model. This study demonstrated that a rigorously developed patient-specific computational model can provide useful insights into underlying mechanisms causing PVL and potentially assist in pre-operative planning for TAVR to minimize PVL.

Abstract 20549: Patient-Specific CT Image-Based Engineering Analysis of Transcatheter Aortic Valve Replacement - Implications for Aortic Root Rupture

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Qian Wang ◽  
Caitlin Martin ◽  
Susheel Kodali ◽  
Jonathon Leipsic ◽  
Philipp Blanke ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Valve Replacement ◽  
Clinical Outcomes ◽  
Valve Replacement ◽  
Aortic Root ◽  
Transcatheter Aortic Valve Replacement ◽  
Aortic Rupture ◽  
Blind Study ◽  
Patient Specific ◽  
Transcatheter Aortic Valve

Introduction: Despite the increased global experience with transcatheter aortic valve replacement (TAVR), there remain major adverse clinical events. One of the most severe complications of TAVR is aortic rupture. Although several clinical risk factors of TAVR-induced rupture have been identified, the mechanisms remain largely unknown. The objective of this study was to use computational models to predict potential aortic rupture in TAVR patients. Methods: Pre-procedural CT scans of TAVR patients were used to reconstruct patient-specific finite element (FE) models, which included the aortic root, aortic leaflets, calcification, mitral-aortic intervalvular fibrosa, anterior mitral leaflet, fibrous trigones, and left ventricle. Stent deployment was simulated in a total of 25 patients to evaluate the potential for aortic rupture. Our research design consisted of two phases: Phase One, which was to develop and calibrate FE modeling techniques by retrospectively analyzing 7 Edwards SAPIEN cases with known results; and Phase Two, which was to implement the modeling methodology developed in Phase One to conduct a blind study of 18 cases from a database of 60 patients consisting of 50% rupture cases. For the blind study, FE simulations were completed by researchers blind to the clinical outcomes, and data analysis was conducted by an independent researcher. Results: Simulations correctly predicted 83% of the rupture cases. The balloon pressure at time of rupture was approximately 3.52 atm and 2.53 atm for SAPIEN 23 and 26 valves, respectively. The average contact force between the stent and native tissue was about 81N. Conclusion: Our analysis of over 18 patients suggested that the TAVR outcome could depend on the patient-specific aortic sinus shape, calcification volume, shape, location, and orientation. These results demonstrate the potential for simulation-based pre-TAVR planning tools to evaluate device performance and improve clinical outcomes.

scholarly journals P218 Accuracy and reproducibility of aortic root assessment by eSie Valves in patients candidate to transcatheter aortic valve implantation: a comparative study with computed tomography

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
G Granata ◽  
A Veltri ◽  
S Iuliano ◽  
V Romano ◽  
S Stella ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Coronary Artery ◽  
Aortic Valve ◽  
Transcatheter Aortic Valve Implantation ◽  
Aortic Root ◽  
3D Model ◽  
Transcatheter Aortic Valve ◽  
Aortic Valve Implantation ◽  
Coronary Ostia ◽  
Valve Implantation

Abstract Background Accurate imaging assessment of the aortic root (AR) is critical for prosthesis sizing in transcatheter aortic valve implantation. Multislice computed tomography (MSCT) is the gold standard for this purpose. 3D transesophageal (3D-TOE) reconstruction tools have recently been introduced, which automatically configures a geometric model of AR from 3D-TOE dataset and perform quantitative analyses of the AR. Purpose The aim of the study was to compare semi-automated measurements of AR obtained by eSie Valves (EV) (Siemens Medical Solution, California, USA) tool with MSCT. Methods We prospectively enrolled 26 consecutive patients (mean age 79.5 ± 7.5 years; 38% men) with severe symptomatic aortic stenosis (mean gradient 48.8± 13.6 mmHg) who underwent both 3D-TOE and MSCT as part of TAVI evaluation protocol. Volumetric datasets of the AR, acquired with 3D-TOE in mid-esophageal view, were analyzed with EV tool. EV tool automatically detected AR landmarks and, after user validation, created 3D model of AR providing values of area, perimeter, diameters of aortic annulus (AA) and coronary ostia heights (Fig 1). Results EV tool analysis on 3D-TOE volumetric data sets was feasible in all patients. Strong correlation between EV tool and MSCT assessment for AA major diameter (r = 0.79), AA minor diameter (r = 0.81), AA perimeter (r = 0.89) and AA area (r = 0.89) (all p< 0.0001) was found. On average EV tool underestimated MSCT measurements of AA major diameter (1.2 mm, 4.5%), AA minor diameter (2.6 mm, 11.3%), AA perimeter (4 mm, 5.2%) and AA area (65.3 mmq, 13.6%). Moderate correlation between the two methods, already in this initial sample, for right coronary artery ostium height (r = 0.53, p = 0.007) was discovered. Finally, weak correlation for left coronary artery ostium height (r = 0.33, p = 0.1) was revealed. EV tool measurements from two different volumetric datasets of the same patient showed an excellent reproducibility intraclass correlation coefficient (ICC) for AA area 0.94 and ICC for right coronary height 0.98. Conclusion With these initial results EV tool could be used in clinical practice for quick and reliable assessment of AA area, perimeter and diameters. A larger group of patients will be needed to assess the consistency of coronary ostia height evaluation by EV tool. Abstract P218 Figure. eSie Valve landmarks and 3D model of AR

scholarly journals Self-navigated MRI 3D whole heart sequence for non-enhanced aortic root measurement in transcatheter aortic valve intervention: comparison to cardiac CT

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Holzknecht ◽  
M Pamminger ◽  
C Tiller ◽  
C Kranewitter ◽  
C Kremser ◽  
...  
Keyword(s):  
Image Quality ◽  
Aortic Valve ◽  
Lower Limit ◽  
Aortic Root ◽  
Kappa Statistics ◽  
Transcatheter Aortic Valve ◽  
Upper Limit ◽  
Significant Difference ◽  
Coronary Ostia ◽  
Whole Heart

Abstract Purpose To evaluate image quality, inter-observer reliability and diagnostic accuracy of self-navigated noncontrast 3D whole-heart magnetic resonance angiography (MRA) for transcatheter aortic valve intervention (TAVI) evaluation in comparison to standardized contrast-enhanced computed tomography angiography (CTA). Methods Whole-heart 1.5 T MRA was performed in 33 patients (aged 84 years [IQR 79–86], 48% male) for aortic root sizing and measurements of coronary ostia heights. A subgroup of 18 (55%) patients underwent additional CTA as gold standard for TAVI measurements. Image quality was assessed by a 4-point Likert scale, continuous MRA and CTA measurements were compared with regression and Bland-Altman analysis, valve sizing by kappa statistics. Results Median image quality of MRA as rated by two observers according was 1.5 [IQR 1.5–2.5]. In 4 patients (12%) one coronary ostium each (right coronary artery 3, left main artery 1) was not clearly definable on MRA. Inter-observer correlation was substantial to excellent (r=0.61 to 0.92) with a bias of 19 mm2 for annulus area (lower limit of agreement −59 mm2, upper limit of agreement 98 mm2; p=0.009). Aortic root and ostia height measurements by MRA and CTA showed substantial to excellent correlation (r=0.65 to 0.90) with no significant bias (all p≥0.333). Mean annulus area for MRA was 414±71 mm2 and for CTA 422±80 mm2 (r=0.9) with a bias of −8 mm2 (lower limit of agreement −79 mm2, upper limit of agreement −62 mm2; p=0.333). Regarding prosthetic valve sizing there was complete consistency between MRA and CTA-based decisions (κ=1). Conclusion Self-navigated noncontrast 3D whole-heart MRA enables reliable aortic root TAVI measurements without significant difference to standardized CTA. Prosthesis sizing by MRA measurements would completely match to CTA-based choice. However, in some cases coronary ostia may be difficult to define. Funding Acknowledgement Type of funding source: None

scholarly journals Bioengineering Case Study to Evaluate Complications of Adverse Anatomy of Aortic Root in Transcatheter Aortic Valve Replacement: Combining Biomechanical Modelling with CT Imaging

2020 ◽  
Vol 7 (4) ◽  
pp. 121
Author(s):  
Cristiano Spadaccio ◽  
Laura Mazzocchi ◽  
Irina Timofeva ◽  
Laurent Macron ◽  
Carlo Nicola De Cecco ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Valve Replacement ◽  
Valve Replacement ◽  
Aortic Root ◽  
Transcatheter Aortic Valve Replacement ◽  
Specific Treatment ◽  
Patient Specific ◽  
Transcatheter Aortic Valve ◽  
Biomechanical Modelling ◽  
Stent Deformation

Gated computed tomography (CT) might not adequately predict occurrence of post-implantation transcatheter aortic valve replacement (TAVR) complications in hostile aortic root as it would require a more complex integration of morphological, functional and hemodynamical parameters. We used a computational framework based on finite element analysis (FEA) to simulate patient-specific implantation. Application of biomechanical modelling using FEA to gated-CT was able to demonstrate the relation of the device with voluminous calcification, its consequent misalignment and a significant stent deformation. Use of FEA and other advanced computed predictive modelling techniques as an adjunct to CT scan could improve our understanding of TAVR, potentially predict complications and fate of the devices after implantation and inform patient-specific treatment.

scholarly journals Impact of aortic root geometry on hydrody-namic performance of transcatheter aortic valve prostheses

2017 ◽  
Vol 3 (2) ◽  
pp. 509-512
Author(s):  
Sebastian Kaule ◽  
Sylvia Pfensig ◽  
Robert Ott ◽  
Stefan Siewert ◽  
Niels Grabow ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Root ◽  
Water Soluble ◽  
Hydrodynamic Performance ◽  
Worst Case ◽  
Testing Environment ◽  
Transcatheter Aortic Valve ◽  
Valve Prostheses ◽  
Hydrodynamic Testing

AbstractAssessment of hydrodynamic performance of transcatheter aortic valve prostheses (TAVP) in vitro is es-sentially in the fields of development and approval of novel implants. For the prediction of clinical performance, in vitro testing of TAVP allows for benchmarking of different devic-es, likewise. In addition to the implant itself, also the testing environment has a crucial influence on leaflet dynamics and quantitative test results like effective orifice area (EOA) or aortic regurgitation.Therefore, within the current study we developed simpli-fied physiological and pathophysiological vessel models of the aortic root as a tool for in vitro hydrodynamic testing of TAVP in idealized and worst case conditions. We used 3D printing and silicone cast molding for manufacturing of aortic root models with variable degree of stenosis. Design of aortic roots with normal, mild and severe stenosis was developed according to Reul et al. For manufacturing of tripartite cast-ing molds, a 3D printer was used. Both outer mold parts and the mold core were manufactured from polylactide filament and water soluble polyvinylalcohol filament, respectively. In vitro hydrodynamic performance testing of an exemplary commercially available TAVP implanted in different aortic root models was conducted according to DIN EN ISO 5840-3:2013, using a pulse duplicator system. Manufactured aortic root models were highly transparent, dimensionally stable and therefore suitable for hydrodynamic testing of TAVP. Both, EOA and regurgitant fraction in-creased with increasing degree of stenosis from 1.6 ± 0.1 cm2 to 1.8 ± 0.1 cm2 and 8.6 ± 6.5% to 20.2 ± 4.2% (n = 30 cy-cles), respectively.We successfully developed a testing environment ena-bling sophisticated evaluation of hydrodynamic performance of TAVR in pathophysiological worst case conditions.

Sign in / Sign up

Export Citation Format

Share Document