[1] Imperial Coll London Imperial Coll NHS Trust, Kennedy Inst Rheumatol, Charing Cross Hosp, London W6 8RF, England
[2] Imperial Coll London Imperial Coll NHS Trust, Dept Plast & Reconstruct Surg, Charing Cross Hosp, London W6 8RF, England
[3] Bristol Royal Infirm & Gen Hosp, Dept Gen Surg, Bristol, Avon, England
[4] Hillingdon Hosp NHS Trust, Uxbridge, Middx, England