TCT-692 Patient-Specific Design of an Elastomeric Left Atrial Appendage Occluder

Abstract Background and purpose Percutaneous left atrial appendage occlusion (LAAO) depicts an alternative treatment for patients with atrial fibrillation who are deemed for long-term oral anticoagulation therapy. In order to perform a successful LAAO accurate sizing of left atrial appendage (ostium, landing zone and depth) for device selection is essential. Echo-Fluoro fusion imaging in real-time offers with its latest prototype a patient-specific segmented automated 3D heart model and sizing of left atrial appendage (LAA). We therefore aimed to evaluate the automated segmented LAA sizing by comparing to 2D transesophageal (TOE) and MSCT measurements as gold standard. Methods We studied prospectively data of 8 consecutive patients who were admitted to our clinic for left atrial appendage closure. MSCT was performed preprocedural and analyzed with commercially available 3mensio software (Pie medical imaging). 2D TOE measurements and automated segmentation of the LAA and sizing were performed during the procedure by a highly experienced team of periinterventional cardiac imaging specialist and structural heart disease interventionalist who were blinded to the prior MSCT analysis. Dimension of ostium, landing zone (10 mm into the LAA parallel to the ostial plane at the level of the left circumflex for Amplatzer device) and depth (perpendicular to the ostial plane) were obtained in different TOE views according to instructions for use of Amulet Occluder. In order to generate an automated 3 D heart model, a high-quality 3D TOE image of the LAA volume and surrounding structures was acquired. After successful ECG-gated segmentation a 3 D heart model was generated. Automated LAA sizing followed in real-time. All measurements were taken into consideration before device selection. A Kruskal Wallis test was used to compare mean ranks of independent samples. A concordance analysis according to Kendall W was carried out to investigate reliability. Results The mean age of the patients was 82,6±4.15 years and half of the patients were female. All procedures were conducted successfully. The mean values of ostium and landing zone were comparable in TOE, automated sizing and MSCT sizing (ostium: 23,78±2,15 mm vs 25,71±5,25 mm vs 27,35±3,3 mm; (p=0,175); landing zone 22,13±3,18 mm vs 23,57±3,31 mm vs 24,00±3,51 mm; (p=0,377)). Furthermore, a significant concordance between the measurements was shown (ostium W= 0,991; p=0.045, landing zone W=0,835, p=0.014). Conclusion Automated LAA sizing acquired by fusion imaging may be an elegant real-time alternative for precise LAA Occluder device selection and needs to be investigated further.

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Patient-specific catheter shaping for the minimally invasive closure of the left atrial appendage

International Journal of Computer Assisted Radiology and Surgery ◽

10.1007/s11548-018-1752-4 ◽

2018 ◽

Vol 13 (6) ◽

pp. 837-846

Author(s):

Eva C. Graf ◽

Ilka Ott ◽

Julian Praceus ◽

Felix Bourier ◽

Tim C. Lueth

Keyword(s):

Minimally Invasive ◽

Left Atrial ◽

Left Atrial Appendage ◽

Atrial Appendage ◽

Patient Specific

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Patient-specific 3D-printed Cardiac Model for Percutaneous Left Atrial Appendage Occlusion

Revista Española de Cardiología (English Edition) ◽

10.1016/j.rec.2017.05.028 ◽

2018 ◽

Vol 71 (9) ◽

pp. 762-764 ◽

Cited By ~ 1

Author(s):

Beatriz Vaquerizo ◽

Carmen Escabias ◽

Daniela Dubois ◽

Gorka Gómez ◽

Manuel Barreiro-Pérez ◽

...

Keyword(s):

Left Atrial ◽

Left Atrial Appendage ◽

Atrial Appendage ◽

Patient Specific ◽

Left Atrial Appendage Occlusion ◽

Cardiac Model ◽

3D Printed

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The Value of 3D Printing Models of Left Atrial Appendage Using Real-Time 3D Transesophageal Echocardiographic Data in Left Atrial Appendage Occlusion: Applications toward an Era of Truly Personalized Medicine

Cardiology ◽

10.1159/000447444 ◽

2016 ◽

Vol 135 (4) ◽

pp. 255-261 ◽

Cited By ~ 22

Author(s):

Peng Liu ◽

Rijing Liu ◽

Yan Zhang ◽

Yingfeng Liu ◽

Xiaoming Tang ◽

...

Keyword(s):

Atrial Fibrillation ◽

3D Printing ◽

Real Time ◽

Left Atrial ◽

Left Atrial Appendage ◽

3D Models ◽

Atrial Appendage ◽

Patient Specific ◽

The Real ◽

Echocardiographic Image

Aims and Objectives: The objective of this study was to assess the clinical feasibility of generating 3D printing models of left atrial appendage (LAA) using real-time 3D transesophageal echocardiogram (TEE) data for preoperative reference of LAA occlusion. Background: Percutaneous LAA occlusion can effectively prevent patients with atrial fibrillation from stroke. However, the anatomical structure of LAA is so complicated that adequate information of its structure is essential for successful LAA occlusion. Emerging 3D printing technology has the demonstrated potential to structure more accurately than conventional imaging modalities by creating tangible patient-specific models. Typically, 3D printing data sets are acquired from CT and MRI, which may involve intravenous contrast, sedation, and ionizing radiation. It has been reported that 3D models of LAA were successfully created by the data acquired from CT. However, 3D printing of the LAA using real-time 3D TEE data has not yet been explored. Methods: Acquisition of 3D transesophageal echocardiographic data from 8 patients with atrial fibrillation was performed using the Philips EPIQ7 ultrasound system. Raw echocardiographic image data were opened in Philips QLAB and converted to ‘Cartesian DICOM' format and imported into Mimics® software to create 3D models of LAA, which were printed using a rubber-like material. The printed 3D models were then used for preoperative reference and procedural simulation in LAA occlusion. Results: We successfully printed LAAs of 8 patients. Each LAA costs approximately CNY 800-1,000 and the total process takes 16-17 h. Seven of the 8 Watchman devices predicted by preprocedural 2D TEE images were of the same sizes as those placed in the real operation. Interestingly, 3D printing models were highly reflective of the shape and size of LAAs, and all device sizes predicted by the 3D printing model were fully consistent with those placed in the real operation. Also, the 3D printed model could predict operating difficulty and the presence of a peridevice leak. Conclusions: 3D printing of the LAA using real-time 3D transesophageal echocardiographic data has a perfect and rapid application in LAA occlusion to assist with physician planning and decision making.

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Demonstration of Patient-Specific Simulations to Assess Left Atrial Appendage Thrombogenesis Risk

Frontiers in Physiology ◽

10.3389/fphys.2021.596596 ◽

2021 ◽

Vol 12 ◽

Author(s):

Manuel García-Villalba ◽

Lorenzo Rossini ◽

Alejandro Gonzalo ◽

Davis Vigneault ◽

Pablo Martinez-Legazpi ◽

...

Keyword(s):

Residence Time ◽

Left Atrial ◽

Left Atrial Appendage ◽

Blood Stasis ◽

Bleeding Risk ◽

Atrial Appendage ◽

Patient Specific ◽

Immersed Boundary ◽

Moving Wall ◽

And Function

Atrial fibrillation (AF) alters left atrial (LA) hemodynamics, which can lead to thrombosis in the left atrial appendage (LAA), systemic embolism and stroke. A personalized risk-stratification of AF patients for stroke would permit improved balancing of preventive anticoagulation therapies against bleeding risk. We investigated how LA anatomy and function impact LA and LAA hemodynamics, and explored whether patient-specific analysis by computational fluid dynamics (CFD) can predict the risk of LAA thrombosis. We analyzed 4D-CT acquisitions of LA wall motion with an in-house immersed-boundary CFD solver. We considered six patients with diverse atrial function, three with either a LAA thrombus (removed digitally before running the simulations) or a history of transient ischemic attacks (LAAT/TIA-pos), and three without a LAA thrombus or TIA (LAAT/TIA-neg). We found that blood inside the left atrial appendage of LAAT/TIA-pos patients had marked alterations in residence time and kinetic energy when compared with LAAT/TIA-neg patients. In addition, we showed how the LA conduit, reservoir and booster functions distinctly affect LA and LAA hemodynamics. Finally, fixed-wall and moving-wall simulations produced different LA hemodynamics and residence time predictions for each patient. Consequently, fixed-wall simulations risk-stratified our small cohort for LAA thrombosis worse than moving-wall simulations, particularly patients with intermediate LAA residence time. Overall, these results suggest that both wall kinetics and LAA morphology contribute to LAA blood stasis and thrombosis.

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TCT-522 Quantification of the Relationship between the Left Atrium Pressure and the Ostial Diameter of the Left Atrial Appendage: A Patient-Specific Simulation Study

Journal of the American College of Cardiology ◽

10.1016/j.jacc.2017.09.692 ◽

2017 ◽

Vol 70 (18) ◽

pp. B216-B217

Author(s):

Tianqi Gao ◽

Ali Azadani

Keyword(s):

Left Atrium ◽

Simulation Study ◽

Left Atrial ◽

Left Atrial Appendage ◽

Atrial Appendage ◽

Patient Specific ◽

The Relationship

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Simultaneous Functional and Morphological Assessment of Left Atrial Appendage by 3D Virtual Models

Journal of Healthcare Engineering ◽

10.1155/2019/7095845 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Giorgia Vivoli ◽

Emanuele Gasparotti ◽

Marco Rezzaghi ◽

Elisa Cerone ◽

Massimiliano Mariani ◽

...

Keyword(s):

Left Atrial ◽

Left Atrial Appendage ◽

Thrombus Formation ◽

User Interaction ◽

Atrial Appendage ◽

Patient Specific ◽

3D Analysis ◽

Current Standard ◽

Laa Closure ◽

Simultaneous Assessment

Purpose. The left atrial appendage (LAA) is responsible for thrombus formation in patients with atrial fibrillation. The evaluation of both LAA function and morphology is crucial for the patient characterization and the preprocedural planning of LAA closure intervention. Despite the availability of 3D imaging modalities, the current standard image analysis is based on manual delineation of the LAA contours on 2D views. Methods. In this study, a comprehensive approach based on a full 3D analysis of the tomographic dataset by surface extraction and processing (3D-S) is presented. The proposed method allows extracting functional and morphologic information in the entire cardiac cycle by minimalizing manual user interaction. The proposed methodology has been validated on ten computer tomography datasets. Results. The proposed 3D-S method was feasible in all cases. Reproducibility was improved with respect to the reference 2D manual procedure (2D-S) (coefficient of variation 2.9 vs. 4.1% for diastolic ostium area; 3.8 vs. 6.1% for systolic ostium area; 2.4 vs. 5.3% for diastolic LAA volume; 2.7 vs. 5.9% for systolic LAA volume; and 7.7 vs. 17.1% for LAA ejection fraction). No significant differences were found between 2D-S and 3D-S measurements. Conclusions. In this study, we introduced a fully 3D approach for LAA characterization, allowing the simultaneous assessment of LAA function and geometry. The proposed approach could be used to improve the patient selection and the best sizing of the device for LAA closure and to allow a patient-specific 3D printing.

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Endocardial left atrial appendage occlusion in atrial fibrillation: computational fluid dynamics simulations to assess stroke risk

EP Europace ◽

10.1093/europace/euab116.173 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

A Masci ◽

N D"alessandro ◽

A Scivoletto ◽

S Severi ◽

F Ansaloni ◽

...

Keyword(s):

Fluid Dynamics ◽

Atrial Fibrillation ◽

Computational Fluid Dynamics ◽

Blood Flow ◽

Left Atrial ◽

Left Atrial Appendage ◽

Blood Stasis ◽

Atrial Appendage ◽

Patient Specific ◽

Hemodynamic Changes

Abstract Funding Acknowledgements Type of funding sources: None. Background Percutaneous endocardial left atrial appendage (LAA) occlusion (LAAO) in non-valvular atrial fibrillation (AF) seems comparable to anticoagulation therapy (OAC) as regards thromboembolic risk reduction with a possible additional decrease in major bleeding. LAAO is currently limited to patients with contraindications to OAC, due to its high costs and procedural risks, but better pre-procedural planning and operative techniques might improve the outcome widening practical indications. Computational fluid dynamics (CFD) represents a valuable non-invasive approach to estimate physiologically significant hemodynamic parameters in a complex fluid dynamics system. It might provide a helpful in silico simulation of blood flow patterns within the LA and LAA by using 3D patient-specific models, allowing LAAO planning and effects prediction. Purpose This study’s aim was to simulate the fluid dynamics effects of LAAO in AF patients to predict patient-specific hemodynamic changes caused by applying the two most popular devices. Methods LAAO was simulated on the 3D LA anatomical models obtained from CT data in 5 AF patients, considering the device specific shape. CFD simulations in AF condition were performed both on the whole LA model and on the models with the LAAO performed with the two devices. Significant fluid dynamics indices (blood velocity, vortex structures, LAA ostium velocity, LA blood stasis) were computed to evaluate the changes in the flow patterns after LAAO in relation to the thrombogenic risk. Results Overall we found a more effective washout within the LA after LAAO, in terms of a different spatial distribution of velocities (see figure for a qualitative evaluation of LA blood flow velocity in one patient: (A) model with LA and LAA; models after LAAO applying the Amulet (B) and the Watchman (C) device) and vortex structures (after LAAO, they were decreased in number and increased in size). Moreover, a higher velocity at the mitral valve and at the LAA ostium (peak velocity: 12-17 cm/s in the models with LAA, 40-60 cm/s in LAAO_A and 35-65 in LAAO_W) was detected together with a slightly improved washout effect in terms of blood stasis with the Watchman device (stasis: 3.1-5.7% in the models with LAA, 1.9-4.1% in LAAO_A, 1.7-3.7% in LAAO_W). Conclusions A workflow for simulating the fluid dynamics effects of endocardial LAAO in AF was developed and tested. CFD provides a valuable tool to quantify hemodynamic changes after LAAO and assess thrombogenic risk in patient-specific LA and LAA. Our preliminary results suggest that endocardial LAAO favourably affects blood fluid dynamics in the LA. Abstract figure

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Demonstration of Patient-Specific Simulations To Assess Left Atrial Appendage Thrombogenesis Risk

10.1101/2020.05.07.083220 ◽

2020 ◽

Author(s):

Manuel García-Villalba ◽

Lorenzo Rossini ◽

Alejandro Gonzalo ◽

Davis Vigneault ◽

Pablo Martinez-Legazpi ◽

...

Keyword(s):

Left Atrial ◽

Left Atrial Appendage ◽

Bleeding Risk ◽

Atrial Appendage ◽

Patient Specific ◽

Immersed Boundary ◽

Moving Wall ◽

History Of ◽

Small Cohort ◽

And Function

AbstractAtrial fibrillation (AF) alters left atrial (LA) hemodynamics, which can lead to thrombosis in the left atrial appendage (LAA), systemic embolism and stroke. A personalized risk-stratification of AF patients for stroke would permit improved balancing of preventive anticoagulation therapies against bleeding risk. We investigated how LA anatomy and function impact LA and LAA hemodynamics, and explored whether patient-specific analysis by computational fluid dynamics (CFD) can predict the risk of LAA thrombosis. We analyzed 4D-CT acquisitions of LA wall motion with an in-house immersed-boundary CFD solver. We considered six patients with diverse atrial function, three without a LAA thrombus (LAAT/TIA-neg), and three with either a LAA thrombus (removed digitally before running the simulations) or a history of transient ischemic attacks (LAAT/TIA-pos). We found that blood inside the left atrial appendage of LAAT/TIA-pos patients had marked alterations in residence time and kinetic energy when compared with LAAT/TIA-neg patients. In addition, we showed how the LA conduit, reservoir and booster functions distinctly affect LA and LAA hemodynamics. While the flow dynamics of fixed-wall and moving-wall simulations differ significantly, fixed-wall simulations risk-stratified our small cohort for LAA thrombosis only slightly worse than moving-wall simulations.

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