1. Cardiac Surgery Department, S. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
2. Pediatric Cardiac Surgery and GUCH Unit, S. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
3. Cardiac Surgery Department, Monzino Hospital, Milano, Italy
4. Department of Pathology, S. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy