1. Department of Digestive Surgery, Assistance Publique–Hôpitaux de Paris, Hôpital Saint Antoine, Paris, France
2. Université Pierre et Marie Curie Paris 06, Paris, France
3. Centre of Visceral Surgery and Transplantation, Hôpital de Hautepierre, Université Louis Pasteur, Strasbourg, France
4. Departments of Biostatistics, Institut Paoli Calmettes, Marseille, France
5. Departments of Surgery, Institut Paoli Calmettes, Marseille, France