1. Department of Vascular and Endovascular Surgery, The Royal Oldham Hospital, Pennine Acute Hospitals NHS Trust, Manchester, UK
2. Department of Colorectal Surgery, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK
3. Liverpool Vascular and Endovascular Service, Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool, UK
4. Division of Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester, UK