Hamdy Singab1,*, PhD; Gamal Sami2, 3, PhD
1 Department of Cardiovascular and thoracic Surgery, Faculty of medicine, Ain Shams University, Cairo, Egypt
2 Nasser Institute for Research and Treatment, Cardiothoracic Surgery Cairo, Egypt
3 Department of Cardiovascular and thoracic Surgery, Faculty of medicine, Ain Shams University, Cairo, Egypt