1. Department of Cardiac Surgery; MEDINET Heart Center Ltd.; Nowa Sol Poland
2. Department of Cardiac Surgery; Sana-Heart Center Cottbus; Cottbus Germany
3. Department of Cardiac Surgery; Wroclaw Medical University; Wroclaw Poland
4. Department of General and Oncological Surgery; Hospital in Jelenia Gora; Jelenia Gora Poland
5. Department of Cardiac Surgery; Warsaw Medical University; Warsaw Poland