1 Department of Cardiothoracic & Vascular Surgery, Gouri Devi Institute of Medical Sciences & Hospital, G.T. Road, Rajbandh, Durgapur, West Bengal 713212 India.
2 Department of Cardiothoracic & Vascular Surgery, Peerless Hospitex Hospital & B K Roy Research Centre, Panchashayar, Kolkata, 700094 India.