BACKGROUND:
Evaluate aortic flow characteristics in volunteers and patients following valve-sparing aortic root replacement.
METHODS:
Magnetic resonance imaging (MRI) acquired time-resolved 3D thoracic aortic velocity fields in 10 volunteers (age 20-40 years) and 12 patients (age 25-53 years) after David reimplantation ("T.David-I or T.David-V"). Aortic outflow was evaluated using 3D time-resolved particle traces and velocity vector fields reformatted onto 2D planes. Three radiologist performed a blinded evaluation of systolic vortex formation behind aortic valve cusps and regions of retrograde and helical flow in the ascending aorta rating them 0-3 (0=none, 1=minimal, 2=medium. 3=prominent).
RESULTS:
Systolic vortices were seen in coronary sinuses of all volunteers, greater in the left sinus (2.5±0.5) than the right (1.8±0.8), and in only four non-coronary (NC) sinuses (0.7±0.9). Comparable coronary vortices were detected in all operated patients. Vorticity was minimal for the NC leaflet in T.David-I repairs (0.7±0.7) but was significantly increased in T.David-V NC graft pseudo-sinuses (1.5±0.6, p<0.03). Significantly enhanced retrograde flow (p<0.02) was found in all patients with increased helicity for T.David-V patients (p<0.03).
CONCLUSIONS:
Coronary cusp vorticity is preserved following David reimplantation, regardless of neo-sinus creation. Increased retrograde flow and helicity (more prominent for T.David-V) suggest energy loss. These novel MRI methods will be useful to assess the clinical implications of increased vorticity and altered aortic flow dynamics in patients undergoing various types of valve-sparing aortic root replacement.

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