1. Center for Congenital Heart Disease, Department of Cardiac Surgery, Inselspital, Bern University Hospital, University of Bern , Bern, Switzerland
2. Clinic for Cardiovascular Surgery, University Heart Centre Freiburg-Bad , Krozingen, Germany
3. Faculty of Medicine, Albert Ludwigs University , Freiburg, Germany
4. Department of Cardiology, Inselspital, Bern University Hospital, University of Bern , Bern, Switzerland