G C Chong1, J D W Choi1, T T Lee2, G Carney3. 1. Academic Unit of Surgery, Australian National University Medical School, The Canberra Hospital, Canberra, ACT, Australia. 2. Department of Otolaryngology, Head and Neck Surgery, The Canberra Hospital, Canberra, ACT, Australia. 3. Access Nephrology, Francis Chambers, Woden, Canberra, ACT, Australia.