1. Department of General Surgery, Royal Surrey NHS Foundation Trust , Surrey , UK
2. Department of Upper Gastrointestinal Surgery, Guy’s and St Thomas’ Hospitals NHS Trust , London , UK
3. Department of Upper Gastrointestinal Surgery, Oxford University Hospitals NHS Foundation Trust , Oxford , UK
4. Department of Molecular Medicine and Surgery, Karolinska Institute , Solna , Sweden
5. Department of Upper Gastrointestinal Surgery, Portsmouth Hospitals University NHS Trust , Portsmouth , UK
6. Department of Anaesthesia, Imperial College Healthcare NHS Trust , London , UK
7. Department of Physiotherapy, Queen Elizabeth Hospital Birmingham , Birmingham , UK
8. Department of General Surgery, Imperial College Healthcare NHS Trust , London , UK
9. School of Cancer Sciences, University of Southampton Faculty of Medicine , Southampton , UK
10. Centre for Anaesthesia, Critical Care and Pain Management, University College London Hospitals NHS Foundation Trust , London , UK
11. NIHR Southampton Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust , Southampton , UK