Numerical simulation study of type B aortic dissection using patient-specific reverse engineering and fluid-structure interaction

Abstract

Objective: To construct computational fluid model of type B aortic dissection using patient-specific reverse engineering and fluid-structure interaction, and evaluate the application of computational fluid model on aortic remodeling of type B aortic dissection. Methods: Consecutive computed tomographic angiograph data was acquired from a patient with type B aortic dissection at initial diagnosis, 1 week and 6 years after endovascular repair of primary tear entry and 3 months after endovascular repair of distal tear erosion. Three-dimensional model of aortic dissection was reversely reconstructed by Mimics, and then the model was smoothened by Geomagic. Computational fluid dynamic numerical simulation was performed in ANSYS by the means of two-way fluid-structure interaction, and the relation between blood dynamic characteristic and thrombosed remodeling of type B aortic dissection was evaluated. Results: The computational fluid model of type B aortic dissection using patient-specific reverse engineering and fluid-structure interaction method was successfully constructed. Local peak of blood pressure on the convex surface of junction at aortic arch and descending aorta was found. The wall stress was much higher at the false lumen than that at the true lumen, and the peak of wall stress converged on the edge and tear entry of false lumen. After the exclusion of proximal tear entry, the blood streamline was decreased significantly and flowed reversely. Blood flow in the remaining false lumen was retrograded from the entry at left iliac artery and formed turbulence at the top of false lumen, which was benefit for dissection thrombus remodeling. The higher pressure at the false lumen was associated with the new formation of aortic aneurysm at the distal tear. Conclusion: The computational fluid model of aortic dissection based on patient-specific reverse engineering and fluid-structure interaction method can successfully reveal the relatively truly blood dynamic and wall pressure characteristic of type B aortic dissection.