1. Health Education and Improvement Wales’ School of Surgery , Nantgarw , UK
2. Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales , Treforest , UK
3. Department of Surgery, University Hospital of Wales , Cardiff , UK
4. Wales Institute of Minimal Access Therapy, Cardiff University , Cardiff , UK
5. Department of Surgery, Morriston Hospital , Swansea , UK
6. School of Medicine, Swansea University , Swansea , UK