comparative morphological and morphometric study of mitral valve in man and pig

ABSTRACT

A comparative anatomical study of the mitral valve has been performed on 25 human postmortem hearts [13 males and 12 females] and 20 porcine hearts. The present study offers a detailed anatomical background of the morphological, structural and morphometric similarities and dissimilarities between the mitral valves of these two species in order to highlight the feasibility of the usage of the porcine mitral valve in human mitral valve replacement. The different elements of the mitral valve complex in man and pig were extensively subjected to morphological and histological examinations as well as morphometric assessments. In man, the measurements of most elements of the mitral valve have shown significant lower values in females than in males. The leaflets of the porcine mitral valve have proved to be closely similar to those of the human valve concerning their morphology and most of their morphometric measurements The distribution of the mitral chordae tendineae has shown close similarity between the human and porcine hearts but with significantly higher mean number in the pig. The porcine subatrial papillary muscle has been observed to be formed of a single conical belly while its analogous human posteromedial muscle is formed of multiple interconnected bellies. Histologically, the structure of the mitral valve has been noticeably similar in man and pig except for the finding that smooth muscle fibres are observed in the human posterior mitral leaflet but not in that of the porcine mitral valve. Accordingly, the present study proposes that the porcine mitral valve could be considered as a good alternative to the human valve in valve replacements. A preoperative echocardiography is advised to assess the size of the patient's mitral valve as a guide for selecting a porcine valve of compatible size