Left atrial appendage occlusion device: Development and validation of a finite element model

Abstract

Atrial Fibrillation (AF) is a common disease that significantly increases the risk of strokes. Oral anticoagulants represent the standard preventive treatment, but they involve severe drawbacks, including intracerebral bleedings. Since in patients affected by nonvalvular AF, the Left Atrial Appendage (LAA) is the primary source of thromboembolism, percutaneous closure of the LAA is a viable option for people unsuitable for long-term anticoagulant therapy. However, the complexities related to the implant procedure, occlusion devices and the anatomical variability hinder the pre-operative planning, resulting in unexpected outcomes. In this context, in-silico models may represent a powerful support tool providing clinicians with more detailed information. Nevertheless, few works focusing on numerical modeling of LAA occlusion devices have been presented so far, and a detailed process to assess the model credibility, verifying that different sources of uncertainty did not affect the prediction, is missing. This work aims to illustrate a process that allows to build and validate the numerical model of a commercial occlusion device starting from only one sample available and without data provided by the manufacturer. To better identify potential uncertainties, the validation followed a step-by-step process that led from individual device behavior assessment to interaction with deformable conduit evaluation.

Keywords: Finite element analysis; In-silico modeling; In-vitro testing; Ni-ti, Left atrial appendage; Self-expandable device.