Background: The evaluation of any new cardiac valvular prosthesis should go beyond the classical morbidity
and mortality rates and involve hemodynamic assessment. As a proof of concept, the objective of this study was
to characterise for the first time the hemodynamics and the blood flow profiles at the aortic root in patients
implanted with BioValsalva™ composite valve-conduit using comprehensive MRI and computer technologies.
Methods: Four male patients implanted with BioValsalva™ and 2 age-matched normal controls (NC) underwent cardiac
magnetic resonance imaging (MRI). Phase-contrast imaging with velocity-mapping in 3 orthogonal directions was
performed at the level of the aortic root and descending thoracic aorta. Computational fluid dynamic (CFD) simulations
were performed for all the subjects with patient-specific flow information derived from phase-contrast MR data.
Results: The maximum and mean flow rates throughout the cardiac cycle at the aortic root level were very comparable
between NC and BioValsalva™ patients (541 ± 199 vs. 567 ± 75 ml/s) and (95 ± 46 vs. 96 ± 10 ml/s), respectively.
The maximum velocity (cm/s) was higher in patients (314 ± 49 vs. 223 ± 20; P = 0.06) due to relatively smaller effective
orifice area (EOA), 2.99 ± 0.47 vs. 4.40 ± 0.24 cm2 (P = 0.06), however, the BioValsalva™ EOA was comparable to other
reported prosthesis. The cross-sectional area and maximum diameter at the root were comparable between the two
groups. BioValsalva™ conduit was stiffer than the native aortic wall, compliance (mm2 • mmHg−1 • 10−3
) values were
(12.6 ± 4.2 vs 25.3 ± 0.4.; P = 0.06). The maximum time-averaged wall shear stress (Pa), at the ascending aorta was
equivalent between the two groups, 17.17 ± 2.7 (NC) vs. 17.33 ± 4.7 (BioValsalva™ ). Flow streamlines at the root and
ascending aorta were also similar between the two groups apart from a degree of helical flow that occurs at the outer
curvature at the angle developed near the suture line.
Conclusions: BioValsalva™ composite valve-conduit prosthesis is potentially comparable to native aortic root in
structural design and in many hemodynamic parameters, although it is stiffer. Surgeons should pay more attention
to the surgical technique to maximise the reestablishment of normal smooth aortic curvature geometry to prevent
unfavourable flow characteristics.