Abstract 15519: Fluid Dynamics and Flow Profiles in the Great Arteries in Patients with Transposition of the Great Arteries (TGA) after Arterial Switch Operation with or without Lecompte Maneuver on Long-term Follow-up

Background: Complex fluid dynamics (vorticity, helicity and wall shear stress) in the transposed great arteries in TGA patients after arterial switch operation (ASO) with spiral course or anterior branching of the pulmonary arteries (Lecompte) has been scarcely studied. The aim of this study was a comprehensive assessment of blood flow in the great arteries utilizing advanced MRI techniques two decades after ASO. Methods: 15 TGA patients (Lecompte: n=9, 20.7±2.3 yrs post ASO; non-Lecompte, spiral: n=6, 21.0±1.5 yrs post ASO; single surgeon) and 5 healthy volunteers (22.9±2.2) were studied with high field MRI at 3 Tesla. Blood flow dynamics were calculated from time-resolved 3D flow measurements (4D flow) using novel phase contrast MR-techniques (FOV 250-337 mm2, venc 150 cm/s in 3 othogonal directions, true spatial resolution: 2.5mm3 isotropic, temp. resol 35 ms, TR/TE 4.6/3.2; α=5-10°). A dedicated software was used for colour coded 4D visualisation and grading of blood flow profiles and streamlines (G...