[1] Univ Childrens Hosp, Dept Pediat Surg, Tubingen, Germany
[2] Univ Tubingen, Comprehens Canc Ctr, Dept Gen Visceral & Transplant Surg, Tubingen, Germany
[3] Univ Childrens Hosp, Dept Pediat Cardiol Pulmol & Pediat Intens Care M, Tubingen, Germany
[4] Natl Res Ctr Pediat Hematol Oncol & Immunol, Dept Clin Oncol, Moscow, Russia
[5] Univ Hosp Giessen Marburg, Dept Pediat Surg, Marburg, Germany