1 Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa; Department of Cardiothoracic Surgery, UPMC Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pa. Electronic address: michel_pompeu@yahoo.com.br.
2 Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa; Department of Cardiothoracic Surgery, UPMC Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pa.