[1] Newcastle Univ, Great North Childrens Hosp, Paediat Surg, Teaching Hosp, Newcastle Upon Tyne, Tyne & Wear, England
[2] Univ Paris, Dept Pediat Surg, Necker Enfants Malad Hosp, Paris, France
[3] Sorbonne Univ, Armand Trousseau Hosp, AP HP, Visceral & Neonatal Pediat Surg Dept, Paris, France
[4] Great Ormond St Hosp Sick Children, Paediat Surg, London, England
[5] Hosp Italiano Buenos Aires, Pediat Surg, Buenos Aires, DF, Argentina
[6] Hosp Univ Vall dHebron, Serv Cirugia Pediat, Barcelona, Spain
[7] Hosp Univ & Politecn La Fe, Unidad Cirugia Oncol Pediat, Valencia, Spain
[8] V Buzzi Childrens Hosp, Pediat Surg, Milan, Italy
[9] Univ Paris XI, Hop Univ Paris Sud, Hop Bicetre, AP HP,Pediat Surg, Paris, France
[10] Royal Childrens Hosp, Paediat Surg, Melbourne, Vic, Australia
[11] Univ Padua, Pediat Surg, Dept Womens & Childrens Hlth, Padua, Italy
[12] Univ Children Hosp, Pediat Surg & Urol, Nantes, France
[13] CHU Hop Nord, Serv Chirurg Pediat, St Etienne, France
[14] Univ Genoa, Pediat Surg Unit, Ist Giannina Gaslini Genova, DINOGMI, Genoa, Italy
[15] Univ Liverpool, Alder Hey Childrens Hosp NHS Fdn Trust, Sch Hlth & Life Sci, Dept Paediat Surg, Liverpool, Merseyside, England
[16] Newcastle Univ, Populat Hlth Sci Inst, Newcastle Upon Tyne, Tyne & Wear, England
[17] Oslo Univ Hosp, Rikshosp, Oslo, Norway
[18] Univ Oslo, Oslo, Norway
[19] Ghent Univ Hosp, Princess Elisabeth Childrens Hosp, Dept Gastrointestinal & Paediat Surg, Ghent, Belgium
[20] Univ Childrens Hosp Tuebingen, Dept Pediat Surg & Pediat Urol, Hoppe Seyler Str 3, D-72076 Tubingen, Germany
[21] Munich Univ Hosp, Dept Pediat Surg, Dr von Hauner Childrens Hosp, Munich, Germany