Institution: | a Department of Cardiovascular Surgery, Albert-Ludwigs-University Medical Center, Hugstetter Str. 55, D-79106 Freiburg, Germany b Department of Cardiovascular Surgery, Jikei University Medical Center, Tokyo, Japan cDepartment of Surgical Research, Albert-Ludwigs-University Medical Center, Freiburg, Germany d Department of Thoracic Surgery, Sapporo University Medical Center, Sapporo, Japan |