scholarly journals Investigation of the Hemodynamics Influencing Emboli Trajectories Through a Patient-Specific Aortic Arch Model

Stroke ◽  
2019 ◽  
Vol 50 (6) ◽  
pp. 1531-1538 ◽  
Author(s):  
Fiona Malone ◽  
Eugene McCarthy ◽  
Patrick Delassus ◽  
Jan-Hendrick Buhk ◽  
Jens Fiehler ◽  
...  
Keyword(s):  
Aortic Arch ◽  
Patient Specific ◽  
Arch Model

scholarly journals Patient-Specific Aortic Phantom With Tunable Compliance

2019 ◽  
Vol 2 (4) ◽  
Author(s):  
Antonio Gallarello ◽  
Andrea Palombi ◽  
Giacomo Annio ◽  
Shervanthi Homer-Vanniasinkam ◽  
Elena De Momi ◽  
...  
Keyword(s):  
Aortic Arch ◽  
Computational Models ◽  
Three Dimensional ◽  
Complex Interventions ◽  
Patient Specific ◽  
Arch Model ◽  
Magnetic Resonance Imaging Mri ◽  
Variable Wall ◽  
Silicone Model

Abstract Validation of computational models using in vitro phantoms is a nontrivial task, especially in the replication of the mechanical properties of the vessel walls, which varies with age and pathophysiological state. In this paper, we present a novel aortic phantom reconstructed from patient-specific data with variable wall compliance that can be tuned without recreating the phantom. The three-dimensional (3D) geometry of an aortic arch was retrieved from a computed tomography angiography scan. A rubber-like silicone phantom was manufactured and connected to a compliance chamber in order to tune its compliance. A lumped resistance was also coupled with the system. The compliance of the aortic arch model was validated using the Young's modulus and characterized further with respect to clinically relevant indicators. The silicone model demonstrates that compliance can be finely tuned with this system under pulsatile flow conditions. The phantom replicated values of compliance in the physiological range. Both, the pressure curves and the asymmetrical behavior of the expansion, are in agreement with the literature. This novel design approach allows obtaining for the first time a phantom with tunable compliance. Vascular phantoms designed and developed with the methodology proposed in this paper have high potential to be used in diverse conditions. Applications include training of physicians, pre-operative trials for complex interventions, testing of medical devices for cardiovascular diseases (CVDs), and comparative Magnetic-resonance-imaging (MRI)-based computational studies.

scholarly journals Distribution of Artificial Thrombi Candidates Through Patient-Specific Aortic-Arch Phantoms under Pulsatile Flow Conditions

2021 ◽  
Author(s):  
Marco Testaguzza ◽  
Mehdi Benhassine ◽  
Haroun Frid ◽  
Laurence Gebhart ◽  
Karim Zouaoui Boudjeltia ◽  
...  
Keyword(s):  
Aortic Arch ◽  
Pulsatile Flow ◽  
Patient Specific ◽  
Flow Profile ◽  
In Vitro Test ◽  
Flow Conditions ◽  
Test Bed ◽  
Arch Models ◽  
Artificial Emboli

Abstract Ischemic Stroke is the most frequent type of stroke and is subject to many studies investigating prevention means. Avoiding the difficulties and ethical problems of experimental in-vivo research, in-vitro testing is a convenient way of studying in controlled conditions the morphological impact and mechanical aspects of emboli dynamics. This in-vitro study was performed with two realistic silicone aortic-arch phantoms submitted to physiological pulsatile flow conditions. In the in-vitro test bed, using automatic image tracking and analysis, it was made possible detecting and tracking artificial spherical emboli candidates circulating in the anatomic aortic-arch models under a realistic based-patient blood flow profile. The emboli trajectories as well as their repartition in the different supra-aortic branches are presented for the two aortic-arch geometries obtained from CT scans. Through a statistical analysis performed with several artificial emboli sizes, the experimental study shows that the repartition percentages of the emboli closely follow the flowrate repartition percentages for both aortic-arch models, suggesting that higher flowrates lead to higher concentrations of emboli in a given artery. Sets of human thrombi were also injected and the repartition percentages have been established, giving the same trend as for artificial emboli.

Digital Design and 3D Printing of Aortic Arch Reconstruction in HLHS for Surgical Simulation and Training

2018 ◽  
Vol 9 (4) ◽  
pp. 454-458 ◽  
Author(s):  
Sarah A. Chen ◽  
Chin Siang Ong ◽  
Nagina Malguria ◽  
Luca A. Vricella ◽  
Juan R. Garcia ◽  
...  
Keyword(s):  
3D Printing ◽  
Aortic Arch ◽  
Surgical Simulation ◽  
Three Dimensional ◽  
3D Models ◽  
Digital Design ◽  
Patient Specific ◽  
Aortic Arch Reconstruction ◽  
Arch Reconstruction ◽  
And Training

Purpose: Patients with hypoplastic left heart syndrome (HLHS) present a diverse spectrum of aortic arch morphology. Suboptimal geometry of the reconstructed aortic arch may result from inappropriate size and shape of an implanted patch and may be associated with poor outcomes. Meanwhile, advances in diagnostic imaging, computer-aided design, and three-dimensional (3D) printing technology have enabled the creation of 3D models. The purpose of this study is to create a surgical simulation and training model for aortic arch reconstruction. Description: Specialized segmentation software was used to isolate aortic arch anatomy from HLHS computed tomography scan images to create digital 3D models. Three-dimensional modeling software was used to modify the exported segmented models and digitally design printable customized patches that were optimally sized for arch reconstruction. Evaluation: Life-sized models of HLHS aortic arch anatomy and a digitally derived customized patch were 3D printed to allow simulation of surgical suturing and reconstruction. The patient-specific customized patch was successfully used for surgical simulation. Conclusions: Feasibility of digital design and 3D printing of patient-specific patches for aortic arch reconstruction has been demonstrated. The technology facilitates surgical simulation. Surgical training that leads to an understanding of optimal aortic patch geometry is one element that may potentially influence outcomes for patients with HLHS.

scholarly journals Flow Dynamics in the Aortic Arch and Its Effect on the Arterial Input Function in Cardiac Computed Tomography

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Parastou Eslami ◽  
Jung-Hee Seo ◽  
Albert C. Lardo ◽  
Marcus Y. Chen ◽  
Rajat Mittal
Keyword(s):  
Computed Tomography ◽  
Aortic Arch ◽  
Rise Time ◽  
Arterial Input Function ◽  
Cardiac Computed Tomography ◽  
Time Lag ◽  
Input Function ◽  
Patient Specific ◽  
Descending Aorta ◽  
Coronary Ostia

The arterial input function (AIF)—time-density curve (TDC) of contrast at the coronary ostia—plays a central role in contrast enhanced computed tomography angiography (CTA). This study employs computational modeling in a patient-specific aorta to investigate mixing and dispersion of contrast in the aortic arch (AA) and to compare the TDCs in the coronary ostium and the descending aorta. Here, we examine the validity of the use of TDC in the descending aorta as a surrogate for the AIF. Computational fluid dynamics (CFD) was used to study hemodynamics and contrast dispersion in a CTA-based patient model of the aorta. Variations in TDC between the aortic root, through the AA and at the descending aorta and the effect of flow patterns on contrast dispersion was studied via postprocessing of the results. Simulations showed complex unsteady patterns of contrast mixing and dispersion in the AA that are driven by the pulsatile flow. However, despite the relatively long intra-aortic distance between the coronary ostia and the descending aorta, the TDCs at these two locations were similar in terms of rise-time and up-slope, and the time lag between the two TDCs was 0.19 s. TDC in the descending aorta is an accurate analog of the AIF. Methods that use quantitative metrics such as rise-time and slope of the AIF to estimate coronary flowrate and myocardial ischemia can continue with the current practice of using the TDC at the descending aorta as a surrogate for the AIF.

scholarly journals Engineering Analysis of Aortic Wall Stress in the Surgery of V-shape Resection of the Noncoronary Sinus

2020 ◽  
Author(s):  
Hai Dong ◽  
Minliang Liu ◽  
Tongran Qin ◽  
Liang Liang ◽  
Bulat Ziganshin ◽  
...  
Keyword(s):  
Aortic Aneurysm ◽  
Stress Field ◽  
Aortic Arch ◽  
Aortic Root ◽  
Wall Stress ◽  
Aortic Aneurysms ◽  
Patient Specific ◽  
Rupture Risk ◽  
Ascending Aortic Aneurysm ◽  
Post Surgery

AbstractAscending aortic aneurysms often include the sinotubular junction (STJ) and extend into the root portion of the aorta. The novel surgery of the V-shape resection of the noncoronary sinus of the aortic root has been shown to be a simpler procedure, comparing with traditional surgeries such as full aortic root replacement, for patients with moderate ascending aortic aneurysm and aortic root ectasia. This novel surgery could reduce the diameter and cross-sectional area of the aortic root. However, the detailed effect on the stress field and the rupture risk of the aortic root and aneurysm has not been fully investigated. In this study, we performed patient-specific finite element (FE) analysis based on the 3D geometries of the aortic root and ascending aortic aneurysm, reconstructed directly from the clinical computed tomographic (CT) images. By comparing the pre- and post-surgery results, we investigated the influence of the V-shape surgery on the stress field and rupture risk of the aortic root, ascending aortic aneurysm and aortic arch. It was found that the surgery could significantly reduce the wall stress of the aortic root, ascending aortic aneurysm, as well the aortic arch, and hence lower the rupture risk.

Blood Flow Manipulation in the Aorta With Coarctation and Arch Narrowing for Pediatric Subjects

2020 ◽  
Vol 88 (2) ◽  
Author(s):  
Yuxi Jia ◽  
Kumaradevan Punithakumar ◽  
Michelle Noga ◽  
Arman Hemmati
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Aortic Arch ◽  
Flow Direction ◽  
Upper Body ◽  
Patient Specific ◽  
Shear Stresses ◽  
Wall Shear

Abstract The characteristics of blood flow in an abnormal pediatric aorta with an aortic coarctation and aortic arch narrowing are examined using direct numerical simulations and patient-specific boundary conditions. The blood flow simulations of a normal pediatric aorta are used for comparison to identify unique flow features resulting from the aorta geometrical anomalies. Despite flow similarities compared to the flow in normal aortic arch, the flow velocity decreases with an increase in pressure, wall shear stress, and vorticity around both anomalies. The presence of wall shear stresses in the trailing indentation region and aorta coarctation opposing the primary flow direction suggests that there exist recirculation zones in the aorta. The discrepancy in relative flowrates through the top and bottom of the aorta outlets, and the pressure drop across the coarctation, implies a high blood pressure in the upper body and a low blood pressure in the lower body. We propose using flow manipulators prior to the aortic arch and coarctation to lower the wall shear stress, while making the recirculation regions both smaller and weaker. The flow manipulators form a guide to divert and correct blood flow in critical regions of the aorta with anomalies.

Patient-specific three-dimensional aortic arch modeling for automatic measurements: clinical validation in aortic coarctation

2020 ◽  
Vol 21 (7) ◽  
pp. 517-528
Author(s):  
Benedetta Leonardi ◽  
Giuseppe D’Avenio ◽  
Dime Vitanovski ◽  
Mauro Grigioni ◽  
Marco A. Perrone ◽  
...  
Keyword(s):  
Aortic Arch ◽  
Aortic Coarctation ◽  
Three Dimensional ◽  
Patient Specific ◽  
Clinical Validation

Abstract 14618: Bicuspid Aortic Valve Morphology and Risk Factors of Abnormal Hemodynamics: An Experimental Investigation of Velocity, Vorticity and Eccentricity of Systolic Jet Stream, Using a Magnetic Resonance Imaging Compatible Pulsatile Flow Circulation System

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Kaoru Hattori ◽  
Natsuki Nakama ◽  
Jumpei Takada ◽  
Gohki Nishimura ◽  
Ryo Moriwaki ◽  
...  
Keyword(s):  
Risk Factor ◽  
Aortic Valve ◽  
Aortic Arch ◽  
Bicuspid Aortic Valve ◽  
Pulsatile Flow ◽  
Aortic Wall ◽  
Circulation System ◽  
Arch Model ◽  
Flow Vorticity ◽  
Flow Circulation

Introduction: Abnormal hemodynamics with bicuspid aortic valve (BAV) is influenced by the BAV morphology. However, due to the morphological variety, the relationship between BAV morphology and hemodynamics has not been well clarified. We experimentally investigated influences of BAV morphology on hemodynamics. Methods: An MRI compatible pulsatile flow circulation system incorporating an aortic valve model and morphologically relevant aortic arch model was developed. Two types of BAV models with cusp angles of 240-120 (asymmetric BAV) and 180-180 (symmetric BAV) were prepared using bovine aorta and pericardium. The vorticity and eccentricity of jet in the aortic arch model in systolic phase were assessed using 4D-flow MRI. Streamlines at peak systole were compared among 5 BAV morphologies defined based on the symmetry and the position of leaflets (Fig). Results: Eccentric supra-valvular jets directed to the aortic wall faced to the smaller leaflet were present in the 3 asymmetric BAVs. In the ABAV-1, a markedly eccentric jet impinging on the aortic outer curvature was present. In the ABAV-2, a left-posterior directed jet shifting to the outer curvature of proximal arch was present. The asymmetric BAVs induced larger flow vorticity in the ascending aorta than the symmetric BAVs (ABAV-1 vs -2 vs -3 vs SBAV-1 vs -2, 0.018 vs 0.019 vs 0.014 vs 0.010 vs 0.011 m 2 /s). The ABAV-2 had a larger vortex in the middle arch than the ABAV-1 (ABAV-2 vs -1, 0.010 vs 0.005 m 2 /s). Conclusion: Our study indicated that the angles and orientations of the BAV impacted on the locations of jets impinging on the aortic wall and magnitudes of vorticities in systole. In the asymmetric BAVs, the direction of jet was influenced by the position of smaller leaflet. Our data suggests that the ABAV-1 morphology may be a risk factor inducing asymmetric aneurysm bulged toward the aortic outer curvature, while the ABAV-2 morphology may be a risk factor of an aortic aneurysm involving the transvers arch.

Sign in / Sign up

Export Citation Format

Share Document