[1] Hannover Med Sch, Clin Gen Visceral & Transplant Surg, D-30625 Hannover, Germany
[2] Univ Tubingen, D-72076 Tubingen, Germany
[3] Baxter Innovat GmbH, A-1220 Vienna, Austria
[4] Heidelberg Univ, Surg Clin, Clin Gen Visceral & Transplant Surg, D-69120 Heidelberg, Germany