Computational fluid dynamics simulation to evaluate aortic coarctation gradient with contrast-enhanced CT.
Coarctation of aorta (CoA) is a narrowing of the aorta leading to a pressure gradient (ΔP) across the coarctation, increased afterload and reduced peripheral perfusion pressures. Indication to invasive treatment is based on values of maximal (systolic) trans-coarctation ΔP. A computational fluid dynamic (CFD) approach is herein presented for the non-invasive haemodynamic assessment of ΔP across CoA. Patient-specific CFD simulations were created from contrast-enhanced computed tomography (CT) and appropriate flow boundary conditions. Computed ΔP was validated with invasive intravascular trans-CoA pressure measurements. Haemodynamic indices, including pressure loss coefficient (PLc), time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI), were also quantified. CFD-estimated ΔP values were comparable to the invasive ones. Moreover, the aorta proximal to CoA was exposed to altered TAWSS and OSI suggesting hypertension. PLc was found as a further geometric marker of CoA severity. Finally, CFD-estimated ΔP confirmed a significant reduction after percutaneous balloon dilatation and stenting of the CoA in one patient (e.g. from ΔP∼52 mmHg to ΔP∼3 mmHg). The validation of the ΔP computations with catheterisation measurements suggests that CFD simulation, based on CT-derived anatomical data, is a useful tool to readily quantify CoA severity.
a Dipartimento di Ingegneria Chimica , Gestionale, Informatica e Meccanica, Universita' di Palermo , Viale delle Scienze Ed. 8, 90128 Palermo , Italy.
Antonino
A
Rinaudo
Giuseppe
G
D'Ancona
Roberto
R
Baglini
Andrea
A
Amaducci
Fabrizio
F
Follis
Michele
M
Pilato
Salvatore
S
Pasta
coarctation of aorta; computational fluid dynamics; contrast-enhanced computed tomography; pressure gradient