[1] Vrije Univ Amsterdam, Univ Hosp, Dept Otorhinolaryngol Head & Neck Surg, NL-1007 MB Amsterdam, Netherlands
[2] Vrije Univ Amsterdam, Med Ctr, Dept Otorhinolaryngol Head & Neck Surg, NL-1007 MB Amsterdam, Netherlands
[3] Vrije Univ Amsterdam, Med Ctr, Dept Pediat Surg, NL-1007 MB Amsterdam, Netherlands
[4] Vrije Univ Amsterdam, Med Ctr, Dept Pediat Anesthesiol, Pediat Intens Care Unit, NL-1007 MB Amsterdam, Netherlands
[5] Med Ctr Alkmaar, Dept Pediat, Alkmaar, Netherlands