[1] Baylor Coll Med, Dept Surg, Houston, TX 77030 USA
[2] Michael E DeBakey VA Med Ctr, Houston, TX USA
[3] Texas Heart Inst, Dept Cardiovasc Surg, Houston, TX 77025 USA
[4] Cleveland Clin, Dept Thorac & Cardiovasc Surg, Cleveland, OH 44106 USA
[5] Stony Brook Med, Dept Surg, Stony Brook, NY USA
[6] Northport VA Med Ctr, Res & Dev Off, Northport, NY USA
[7] Brigham & Womens Hosp, Dept Surg, 75 Francis St, Boston, MA 02115 USA
[8] Harvard Med Sch, Boston, MA USA
[9] West Virginia Univ, Div Cardiothorac Surg, Morgantown, WV 26506 USA
[10] Emory Univ, Div Cardiothorac Surg, Atlanta, GA 30322 USA
[11] Univ Maryland, Sch Med, Div Cardiac Surg, Baltimore, MD 21201 USA
[12] Univ Pittsburgh, Sch Med, Dept Cardiothorac Surg, Div Cardiac Surg, Pittsburgh, PA USA
[13] Stanford Univ, Dept Surg, Palo Alto, CA 94304 USA
[14] Med Coll Wisconsin, Div Cardiothorac Surg, Milwaukee, WI USA
[15] Zablocki VA Med Ctr, Milwaukee, WI USA
[16] Univ Colorado, Dept Surg, Denver, CO 80202 USA
[17] Denver VA Med Ctr, Aurora, CO USA
[18] Birmingham VA Med Ctr, Birmingham & Tuscaloosa Hlth Serv Res & Dev Progr, Birmingham, AL USA
[19] Univ Alabama Birmingham, Dept Surg, Birmingham, AL 35294 USA