1. Department of Pediatric Surgery, CHU Estaing, Claude
Bernard University-Lyon I, Faculty of Medicine, 43
Boulevard du 11 Novembre 1918, 69622 Villeurbanne
CEDEX, France.
2. Department of Pediatric Surgery, CHU Estaing, 1
Place Lucie et Raymond Aubrac 63003 Clermont Ferrand, France.
3. Biostatistics unit, DRCI, CHU Clermont-Ferrand, 58
rue Montalambert, 6300 Clermont Ferrand, France.
4. Université d’Auvergne, Faculty of Medicine, Department
of Pediatric Surgery, CHU Estaing, 1
Place Lucie et Raymond Aubrac, 63003 Clermont Ferrand, France.