- Oral presentation
- Open Access
Differences in pulmonary flow patterns between surgical and percutaneous implanted bovine valves to restore the right ventricle outflow tract continuity: a four dimensional flow magnetic resonance study
Journal of Cardiovascular Magnetic Resonancevolume 16, Article number: O44 (2014)
In patients with congenital heart defects, restoration of the right ventricle outflow tract (RVOT) continuity by surgical or percutaneous bovine valve implantation is a common procedure. Flow characteristics in such valves are complex, therefore the aim of this study was demonstrating the potential application of 4D MRI flow for the comprehensive assessment of pulmonary flow patterns after surgical and percutaneous bovine valve implantation in the RVOT.
Fifteen patients after percutaneous bovine valve implantation (17.2 ± 2.0 years), 15 patients after surgical implantation (15.8 ± 1.7 years), and 15 healthy volunteers (as a control group) (16.5 ± 1.5 years) were included. All subjects underwent a comprehensive cardiac MRI protocol. Analysis focused on the presence of vertical flow patterns; pulmonary flow eccentricity and wall shear rate (WSR) assessment.
Patients with percutaneous implantation showed an eccentric pulmonary flow (deviation angle from the midline 31 ± 10 degree) with vortex formation (vortex size 73 ± 18%), and a significant asymmetric elevated WSR at focal regions of the conduit. (Figure 1) Vortex size was positively correlated with the pressure gradient across the valve and with the flow deviation angle. In contrast, those after surgical implantation showed a laminar pulmonary flow with no visible vortex and had symmetric, although elevated WSR in the conduit regions.(Figure 2)
Pulmonary flow patterns differ significantly between patients with a surgical and percutaneously implanted bovine valve in the RVOT. Longer follow up studies will be required to determine the implications of such knowledge for prognosis and therapy.