1. Department of Oncology and Metabolism, University of Sheffield , Sheffield, UK
2. Department of Academic Directorate of General Surgery, Sheffield Teaching Hospitals NHS Foundation Trust , Sheffield, UK
3. Department of Mater Infirmorum , Belfast, UK
4. Department of General Surgery, Ysbyty Gwynedd Hospital , Bangor, UK
5. Department of General Surgery, Calderdale and Huddersfield NHS Foundation Trust , Huddersfield, UK