[1] Univ Lausanne Hosp, Dept Surg & Anesthesiol, Sept Surg Unit, CH-1011 Lausanne, Switzerland
[2] Univ Basel, Fac Med, CH-4056 Basel, Switzerland
[3] Kantonsspital Aarau, Dept Med, Div Infect Dis, CH-5000 Aarau, Switzerland
[4] Univ Basel Hosp, Dept Neurosurg, CH-4056 Basel, Switzerland
[5] Free & Humboldt Univ Berlin, Univ Med, Charite, D-10117 Berlin, Germany
[6] Spital Netz Bern Hosp Tiefenau Ziegler, Dept Med, Bern, Switzerland