Background: Patients with atrial fibrillation (AF) are at risk of emboli. Commonly, the source for emboli during AF is stasis in the left atrial appendage (LAA). We propose a new technique for reducing the risk of thrombi formation by folding the LAA into the left atrium. This technique changes the shape of the atrium and may affect the flow profile in it. Purpose. The goal of the present study was to investigate the influence of LAA invagination procedure on the left atrial blood flow in a computer model.
Methods:The study was based on Computational Fluid Dynamic (CFD) analysis that simulates the left atria during atrial fibrillation. A comparison of the flow pattern between non invaginated model (chicken Wing model) with an invaginated LAA models (clip and lasso) was performed.
Results: The Chicken wing model velocity and shear rate maximal values (12.5 [cm/sec] and 100 [Hz], respectively) indicated a potential for emboli formation. The lasso model`s velocity and shear rate maximal values (29 [cm/sec] and 207 [Hz], respectively) as well as the clip model (30 [cm/sec] and 204 [Hz], respectively) indicated a meaningful improvement and decreased the risk of thrombus formation.
Conclusions: The invagination process (both lasso and clip model) could eliminate low velocities (blood stasis) and decrease the shear rates, thereby decreasing the risk of thrombi formation during atrial fibrillation. The results of this study suggest that further investigation of the LAA invagination method in order to reduce embolic threat in patients with AF is worthwhile.
