[1] Univ Heart Ctr Freiburg Bad Krozingen, Dept Cardiovasc Surg, Freiburg, Germany
[2] Harvard Med Sch, Massachusetts Gen Hosp, Dept Cardiac Surg, Boston, MA USA
[3] Univ Hosp Freiburg, Dept Radiol, Freiburg, Germany
[4] Univ Heart Ctr Freiburg Bad Krozingen, Dept Anesthesiol, Freiburg, Germany
[5] Univ Hosp Freiburg, Dept Anesthesiol, Freiburg, Germany
[6] Albert Ludwigs Univ Freiburg, Fac Med, Freiburg, Germany