[1] Cambridge Univ Hosp NHS Trust, Dept Otolaryngol Head & Neck Surg, Cambridge, England
[2] Dept Otolaryngol Head & Neck Surg, Mayo Clin, Rochester, MN USA
[3] Princess Alexandra Hosp, Dept Otolaryngol Head & Neck Surg, Brisbane, Qld, Australia
[4] Addenbrookes Hosp, Clin 10, Hills Rd, Cambridge CB2 0QQ, England