1. Department of Surgery , Cardiothoracic Unit,37 Military Hospital, Accra , Ghana
2. University of Health and Allied Sciences Department of Surgery, School of Medicine, , Ho, Ghana
3. University of Ghana Medical School Department of Surgery, Cardiothoracic Unit, , Legon, Accra , Ghana
4. Korle-Bu Teaching Hospital National Cardiothoracic Centre, , Accra, Ghana
5. Kwame Nkrumah University of Science and Technology Department of Surgery, School of Medicine and Dentistry, College of Health Sciences, , Kumasi, Ghana