Disparity In Morphology Of Papillary Muscles Of The Mitral Valve Complex With Surgical Significance

ABSTRACT

Background: The mitral valve apparatus, consisting of the mitral valve leaflets and commissures and subvalvular apparatus- papillary muscles and chordae tendinae; is one of the most complex and intricately designedstructures present in the human body and therefore the understanding of anatomical variations of papillarymuscles becomes important for surgical interventional procedures, in response to the increasing incidence ofvalvular heart defects. The aim of the cadaveric analysis was to identify the disparity in the morphometry of thepapillary muscles of the mitral valve complex. Therefore this study was taken up with an effort to extend theconcepts previously presented as well as to overcome deficiencies in the knowledge of gross architecture andpositional nomenclature of the papillary muscles.Materials and methods: Fifty formalinized cadaveric hearts were the material for study. Papillary muscles of leftventricle were classified according to a system developed by Berdajs et al., (2005), by precisely measuringshapes lengths and widths.Results: The significant outcome of this study indicates that no two papillary muscles out of the 50 specimenshad the same size, shape or position. All the hearts had two distinct groups of muscles – anterolateral andposteromedial. Specific analysis of each group revealed data regarding the muscles. In the antero-lateral groupof the specimens, the maximum height and width of the muscles was 37.40mm and 17.06mm respectively and inthe postero-lateral group, 33.86 and 26.90mm respectively. Conical shaped muscles were the most commonlyfound muscles owing to the minimum obstruction posed by them to blood flow.Implication Better understanding of morphological variations can help cardiothoracic surgeons to customizesurgical procedures according to the papillary muscle pattern of the individual patient