BackgroundDue to the nature of the percutaneous prosthesis deployment process, a
variation in its final position is expected. Prosthetic valve placement will
define the spatial location of its effective orifice in relation to the
aortic annulus. The blood flow pattern in the ascending aorta is related to
the aortic remodeling process, and depends on the spatial location of the
effective orifice. The hemodynamic effect of small variations in the angle
of inclination of the effective orifice has not been studied in detail.ObjectiveTo implement an in vitro simulation to characterize the
hydrodynamic blood flow pattern associated with small variations in the
effective orifice inclination.MethodsA three-dimensional aortic phantom was constructed, reproducing the anatomy
of one patient submitted to percutaneous aortic valve implantation. Flow
analysis was performed by use of the Particle Image Velocimetry technique.
The flow pattern in the ascending aorta was characterized for six flow rate
levels. In addition, six angles of inclination of the effective orifice were
assessed.ResultsThe effective orifice at the -4º and -2º angles directed the main flow
towards the anterior wall of the aortic model, inducing asymmetric and high
shear stress in that region. However, the effective orifice at the +3º and
+5º angles mimics the physiological pattern, centralizing the main flow and
promoting a symmetric distribution of shear stress.ConclusionThe measurements performed suggest that small changes in the angle of
inclination of the percutaneous prosthesis aid in the generation of a
physiological hemodynamic pattern, and can contribute to reduce aortic
remodeling.