[1] South Warwickshire NHS Fdn Trust, Warwick, England
[2] Univ Hosp Birmingham NHS Fdn Trust, 76 Woolacombe Lodge Rd, Birmingham B296PY, West Midlands, England
[3] Natl & Kapodistrian Univ Athens, Sch Med, Athens, Greece
[4] Gloucestershire Hosp NHS Fdn Trust, ENT & Head & Neck Surg, Gloucester, England
[5] Imperial Coll London, St Marys Hosp, Dept Surg & Canc, Surg Innovat Ctr, London, England
[6] Athens Med Ctr, Marousi & Psychiko Clin, Athens, Greece