1. Department of Cardiac Surgery, Inselspital, Bern University Hospital, University of Bern , Bern, Switzerland
2. Department of Cardiovascular Surgery, University Heart Centre Freiburg - Bad Krozingen, Faculty of Medicine, University of Freiburg, Freiburg, Germany
3. Department of Vascular Surgery, Inselspital, Bern University Hospital, University of Bern , Bern, Switzerland