1 Meharry Medical College, 1005 Dr DB Todd Jr Blvd., Nashville, TN, 37208, USA.
2 University of Alabama at Birmingham Medical Center, Department of Surgery, 1808 7th Ave S BDB 202, Birmingham, AL, 35233, USA.
3 University of Utah School of Medicine, Department of Cardiothoracic Surgery, 30 N 1900 E 3C-127, Salt Lake City, UT, 84132, USA.
4 University of Alabama at Birmingham Medical Center, Department of Surgery, 1808 7th Ave S BDB 202, Birmingham, AL, 35233, USA; American College of Surgeons, Division of Research and Optimal Patient Care, 633 N St Clair St, Chicago, IL, 60611, USA. Electronic address: mma@facs.org.