University of the West of England, Glenside Campus, Blackberry Hill, Stapleton, Bristol, BS16 1DD, UK. Department of General Surgery, Yeovil District Hospital, Higher Kingston, Yeovil, Somerset, BA21 4AT, UK. Medical Affair Department, Pharmacosmos UK Ltd, 33 King's Road, Reading, RG1 3AR, UK. Directorate of Training, Northwick Park Institute of Medical Research, Northwick Park Hospital, Harrow, HA1 3UJ. Division of Surgery and interventional science, University College London, UK.