Atrial fibrillation (AF) is one of the most common cardiac
arrhythmias and is associated to an increasing risk of stroke. Most AF-
related strokes are formed in the left atrial appendage (LAA). To prevent
thrombus formation, LAA occlusion (LAAO) is considered a suitable
alternative for AF patients with contraindications for anti-coagulation
treatment. Nevertheless, LAAO is linked to a non-negligible risk of gener-
ating thrombus at the surface near the device (i.e., device-related throm-
bus, ...
Atrial fibrillation (AF) is one of the most common cardiac
arrhythmias and is associated to an increasing risk of stroke. Most AF-
related strokes are formed in the left atrial appendage (LAA). To prevent
thrombus formation, LAA occlusion (LAAO) is considered a suitable
alternative for AF patients with contraindications for anti-coagulation
treatment. Nevertheless, LAAO is linked to a non-negligible risk of gener-
ating thrombus at the surface near the device (i.e., device-related throm-
bus, DRT), depending on the implantation settings. For instance, it has
been shown that not covering the pulmonary ridge (PR) with the LAAO
increases the risk of DRT. In-silico analysis is a useful tool to better
understand the blood flow patterns after LAAO and predict the risk of
DRT for a given patient and device configuration. In the present work
we designed a modelling pipeline based on fluid simulations, including
a thrombus model using discrete phase modelling, to analyse the risk of
DRT in six patient-specific geometries for different LAAO settings. In
particular, we studied the possible incidence of DRT depending on the
device positioning (covering/uncovering the PR) and type (Amplatzer
Amulet and Watchman FLX). The resulting in-silico indices demon-
strated that covering the PR entails less thrombogenic patterns than
uncovering it. In our study, disk-based devices had better adaptability
to complex LAA morphologies and a slightly minor associated risk of
DRT than non-disk devices.
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