[1] Univ Birmingham, Acad Dept Surg, Birmingham B15 2TT, W Midlands, England
[2] Castle Hill Hosp, Acad Surg Unit, Cottingham, England
[3] Calderdale & Huddersfield NHS Fdn Trus, Dept Vasc Surg, Huddersfield, W Yorkshire, England
[4] Hull Royal Infirm, Hull York Med Sch, Acad Vasc Surg Unit, Kingston Upon Hull HU3 2JZ, N Humberside, England
[5] Univ Leeds, Yorkshire Sch Surg, Dept Postgrad Med & Dent Educ, Leeds LS2 9JT, W Yorkshire, England