[1] Univ S Florida, All Childrens Hosp, Sch Med, Div Thorac & Cardiovasc Surg, St Petersburg, FL 33701 USA
[2] Univ S Florida, All Childrens Hosp, Sch Med, Div Pediat Cardiol, St Petersburg, FL 33701 USA
[3] Great Ormond St Hosp Children, Cardiothorac Unit, London WC1N 3JH, England
[4] Univ Bonn, Div Otolaryngol, D-5300 Bonn, Germany