Sistema ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa


Tesi etd-07042018-095332

Tipo di tesi
Tesi di laurea magistrale
Finite element simulation of the left atrial appendage closure procedure
Corso di studi
relatore Ing. Positano, Vincenzo
controrelatore Ing. Celi, Simona
Parole chiave
  • Finite Element Method
  • LAA Occlusion
  • Watchman Procedure
Data inizio appello
Data di rilascio
Riassunto analitico
In this thesis an approach able to simulate a specific cardiac procedure, the Left Atrium Appendage Occlusion (LAAO) procedure, and to acquire information related to mechanical properties of the left atrial appendage (LAA), with the aim to improve the efficacy of this minimally invasive clinical technique. The procedure consists in the insertion, through the cava vein, of a crimped Nitinol stent, which slowly advance through the left atrium. Once the delivery system is positioned in the LAA orifice, the device is deployed and anchored in such a way to occlude permanently the LAA. The success of this technique is strongly based on a careful selection of the patient and the assessment of the mechanical characteristics of the implantation site for the device.
The aim of this work was to investigate a numerical approach for simulating with Finite Element Method (FEM) the LAAO procedure. Not being present in literature a simile work nowadays, a bottom-up approach has been considered by starting with a LAA idealized geometry and finishing with a patient-specific geometry by using different material models derived from in vivo and in vitro experiments and literature available data.
Different sets of FEM simulations were performed in in order to numerically evaluate the LAAO procedure by taking into account different LAA geometries and material properties.
The results of this thesis show the feasibility of computational tools to simulate the clinical intervention. A further evaluation of the proposed numerical procedure would support the clinical decision for what concern material tissue response, device size, anchoring and pulling forces involved in the process. Surely, several methodologies adopted in this work could be improved and rearranged in term of solution convergence and modelling. Fluid-structure interaction could predict more accurate results and different delivery angles could be considered in the simulations for a better adaptation of the device to a patient-specific implantation site in order to enhance the efficacy of the intervention.