1 Department of Upper Gastrointestinal Surgery, Queen Elizabeth Hospital Birmingham, University Hospital Birmingham NHS Trust, Birmingham, United Kingdom; Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom.
2 Faculty of Medicine, University of Tripoli, Tripoli, Libya.
3 Department of Upper Gastrointestinal Surgery, Queen Elizabeth Hospital Birmingham, University Hospital Birmingham NHS Trust, Birmingham, United Kingdom.
4 Department of Geriatric Medicine, Worcestershire Acute Hospitals NHS Foundation Trust, Worcestershire, United Kingdom.
5 Department of Upper Gastrointestinal Surgery, Queen Elizabeth Hospital Birmingham, University Hospital Birmingham NHS Trust, Birmingham, United Kingdom; Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom. Electronic address: ewen.griffiths@uhb.nhs.uk.