[Assessment with magnetic resonance tomography of anatomy and ventricular function after Mustard correction of transposition of the great arteries].

In order to evaluate postoperative sequelae and ventricular function after Mustard-operation in patients with transposition of the great arteries (TGA), 30 patients were assessed by magnetic resonance imaging in EKG-triggered spin-echo (SE) and gradient-echo (GE) technique. Twenty-three patients, aged 4.7 to 15.8 years, had transposition of the great arteries with intact ventricular septum with or without left-ventricular outflow tract obstruction (TGA+IVS +/- SPS). Seven patients aged 9.5 to 21.7 years had transposition of the great arteries with ventricular septal defect (TGA+VSD). Five patients showed a residual baffle leak, one had a pulmonary venous obstruction, five an obstruction at the caval veins, 13 a left-ventricular outflow tract obstruction, and 14 a tricuspid regurgitation. Right-ventricular enddiastolic volume in patients with TGA+VSD (77.0 +/- 25.5 ml/m2) was significantly higher than in patients with TGA+IVS +/- SPS (61.2 +/- 12.0 ml/m2). In TGA+VSD right-ventricular ejection fraction (47.6 +/- 13.0%) was significantly lower than in patients with TGA+IVS +/- SPS (56.7 +/- 10.7%). The ratio of muscle masses of right to left ventricle was 1.8:1 in patients with TGA+IVS +/- SPS and 2.5:1 in patients with TGA+VSD. In conclusion, after Mustard-operation in patients with transposition of the great arteries (TGA) magnetic resonance imaging provides a comprehensive and noninvasive assessment of postoperative sequelae, residuae, and ventricular function and will, therefore, become the method of choice for postoperative evaluation.