Related Experiment Video
Updated: Jun 30, 2025
Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
Published on: February 26, 2013
Left atrial appendage occlusion: On the need of a numerical model to simulate the implant procedure
Francesca Danielli1, Francesca Berti1, Benigno Marco Fanni2
1LaBS - Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milan, Italy.
Insights
Left atrial appendage occlusion (LAAO) using devices can be improved by using finite element (FE) models for pre-operative planning. These models help optimize device positioning and account for anatomical variations to reduce complications like leakage.
Area of Science:
- Biomedical Engineering
- Cardiovascular Research
- Medical Device Simulation
Background:
- Left atrial appendage occlusion (LAAO) is a key procedure for preventing stroke in atrial fibrillation patients.
- Complex left atrial appendage (LAA) anatomy can lead to procedural difficulties and post-implant issues such as device-related thrombus and peri-device leakage.
Purpose of the Study:
- To develop a detailed finite element (FE) model of LAAO to investigate implant scenarios.
- To derive clinical indications for optimizing device placement and improving procedural outcomes.
- To evaluate the impact of device positioning and LAA wall stiffness on implant success.
Main Methods:
- Creation of a high-fidelity FE model of the Watchman FLX device.
- Development of simplified parametric conduits simulating the LAA deployment zone.
- Evaluation of device-conduit interactions using clinical indicators like device-wall gap and protrusion.
Main Results:
- Device positioning before deployment significantly impacts implant outcomes.
- LAA wall mechanical stiffness is a critical, yet often unknown, parameter for accurate FE modeling.
- Simulations revealed potential discrepancies between the assessed deployed configuration and the final device configuration.
Conclusions:
- FE modeling can enhance pre-operative planning for LAAO procedures.
- Optimizing device positioning and understanding LAA wall properties are crucial for successful LAAO.
- Accurate FE models are essential for predicting and mitigating LAAO-related complications, ensuring safer interventions.
Abstract:
Left atrial appendage occlusion (LAAO) is a percutaneous procedure to prevent thromboembolism in patients affected by atrial fibrillation. Despite its demonstrated efficacy, the LAA morphological complexity hinders the procedure, resulting in postprocedural drawbacks (device-related thrombus and peri-device leakage). Local anatomical features may cause difficulties in the device's positioning and affect the effectiveness of the device's implant. The current work proposes a detailed FE model of the LAAO useful to investigate implant scenarios and derive clinical indications. A high-fidelity model of the Watchman FLX device and simplified parametric conduits mimicking the zone of the LAA where the device is deployed were developed. Device-conduit interactions were evaluated by looking at clinical indicators such as device-wall gap, possible cause of leakage, and device protrusion. As expected, the positioning of the crimped device before the deployment was found to significantly affect the implant outcomes: clinician's choices can be improved if FE models are used to optimize the pre-operative planning. Remarkably, also the wall mechanical stiffness plays an important role. However, this parameter value is unknown for a specific LAA, a crucial point that must be correctly defined for developing an accurate FE model. Finally, numerical simulations outlined how the device's configuration on which the clinician relies to assess the implant success (i.e., the deployed configuration with the device still attached to the catheter) may differ from the actual final device's configuration, relevant for achieving a safe intervention.
