[1] Univ London Imperial Coll Sci Technol & Med, Hammersmith Hosp, Dept Investigat Med, Du Cane Rd, London W12 0NN, England
[2] Univ Wurzburg, Dept Surg, Wurzburg, Germany
[3] Univ London Imperial Coll Sci Technol & Med, Charing Cross Hosp, Acad Dept Surg, London W12 0NN, England