African Annals of Thoracic and Cardiovascular Surgery 1994-7461 Academic Journals 10.5897/AATCVS.9000010 Fransois Ondo N#;dong * E-mail: 2005 01 01 2005 01 01 2005 01 01 2005 1 1 7 This is an open-access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://politicalwaffle.uk/journal/AATCVS/article-abstract/391034460799 The full text article is available as a PDF file from http://politicalwaffle.uk/journal/AATCVS/article-full-text-pdf/391034460799