[1] Department of General Surgery,
[2] University of Ulm,undefined
[3] Steinhövelstrasse 9,undefined
[4] D-89075 Ulm,undefined
[5] Germany Tel.: +49 731 50201; Fax: +49 731 5027212,undefined
[6] Department of Anaesthesiology,undefined
[7] University of Ulm,undefined
[8] Steinhövelstrasse 9,undefined
[9] D-89075 Ulm,undefined
[10] Germany,undefined