1. San Raffaele Hospital, Vita-Salute San Raffaele University, 20132 Milan, Italy
2. Department of Thoracic Surgery, Virginia Mason Medical Center, Seattle, WA 98101, USA
3. Department of Surgery, Washington University in St. Louis, St. Louis, MO 63110, USA
4. Ente Ospedaliero Cantonale, 6500 Lugano, Switzerland
5. Ente Ospedaliero Cantonale, 6900 Bellinzona, Switzerland