Surgical. . Radiologlc Anatomy
Surg Radiol Anat (1990) 12 : 37-41
Journal of Clinical Anatomy
(~) Springer-Verlag 1990
Anatomical study of the human tricuspid valve N Wafae, H Hayashi, LR Gerola and MC Vieira Department of Morphology of the Escola Paulista de Medicina, rua Botucatu 740, 04023-Vila Clementino, S~o Paulo, Brazil 04023
Summary. An anatomical study of the tricuspid valve was carried out in 50 human hearts of both female and male individuals using a m e t h o d of d i s s e c t i o n w h i c h preserves the integrity of the valve. Morphometric criteria such as area of cusp, width of cusp base, relation between commissure depth and cusp depth and morphological criteria such as the presence of atrioventricular cusp node, number of tendinous cords, perimeter of fibrous ring, and properties of papillary m. were adopted for characterization of a cusp. In 64% of cases, commissural cusps were present independent of the number of tricuspid cusps. The tricuspid valve was not consistently tricuspid, but was observed to present 2, 4, 5 or 6 cusps in 72% of cases.
morphom6triques (surface de la cuspide, largeur de la base de cette cuspide, rapport entre la profondeur de la commissure et la profondeur de la cuspide), et aussi des crit6res m o r p h o l o g i q u e s (pr6sence de nodule sur la cuspide atrio-ventriculaire, nombre de cordages tendineux, p6rim6tre de l'anneau fibreux et qualit6 des muscles papiilaires) pour une caract6risation ad6quate des cuspides. Dans 64 % des cas, une valvule avec ses commissures propres 6tait prfsente ind6pendamment des trois cuspides de la valve atrio-ventriculaire droite. Cette valve n'6tait pas toujours tricuspide, mais pr6sentait 2, 4, 5 ou 6 valvules dans 72 % des cas.
Etude anatomique de la valve atrio-ventriculaire droite chez l'homme
The classic description of the tricuspid valve found in the majority of treatise [2-4, 6, 9, 12-14, 17-20] and in specialized works [1, 7, 16] refer to 3 cusps: anterior, septa! and posterior. Some authors also make reference to accessory or commissural cusps [2, 4, 6, 12-14, 18-20] and others admit the existence of different numbers of cusps [8, 21] or subdivided cusps [15]. However, the literature lacks properly established criteria to
R~sum~. Les auteurs ont r6alis6 une 6tude anatomique de la valve atrio-ventriculaire droite sur 50 c0eurs humains des deux sexes partir d'une m6thode de dissection qui pr6serve l'int6grit6 de cette valve. Ils ont utilis6 des crit6res
Offprint requests : N Wafae
distinguish the habitual or supernumerary cusp from a commissural cusp. Embryologically, the division of the common atrioventricular canal into right and left channels ends in the embryo of 40 days. These channels, which are surrounded by mesenchymal subendothelial tissue called endocardial cushions that contribute to the future atriov e n t r i c u l a r v a l v e , grow and straigten approximating the edges of endocardial cushions [5, I1]. The haemodynamic current and the coalescence of spaces among ventricular trabeculated tissue, are mainly responsible for the individualization of cusps of the atrioventricular valves. The aim of this study is to establish morphological and morphometric criteria which might serve as parameters for precise identification of the cusps and fill the existing gap in the literature. Once these parameters are established, this work also defines the number and localization of cusps as well as the presence of supernumerary and commissural cusps. Material and method Fifty human hearts, from male and f e m a l e with no m a c r o s c o p i c evidence of rheumatic and conge-
N Waf~,e ct al: Human tricuspid valve
38
Figs. 1+ 2
1 Photograph of tricuspid valve (after opening of fibrous ring and extension of valve). Representation of measurements: A depth of cusps B depth of nearest commissure from point 0 C depth of farthest commissure from point 0 D width 2 Photograph of tricuspid valve, constituted by 3 cusps: anterior (A). septal (B) and posterior (C), in original position 1 Photographie de la valve atrio-ventriculaire droite (apr~s ouverture de l'anneau fibreux et raise ~tplat de la valve). Mensurations : A profondeur des valvules B profondeur de la commissure la plus proche du point 0 C profondeur de la commissure la plus 61oign6e du point 0 D largeur 2 Photographie de la valve atrio-ventriculaire droite constitu6e par 3 valvules : ant~rieure (A), septale (B), post6rieure (C), dans leur position d'origine
nital lesions or other conditions that could cause alterations to the valve apparatus were selected. Dissection o f the myocardium was carried out from the right atrioventricular fibrous ring to the origin of the papillary muscles, preserving the integrity o f valve apparatus as a whole. Morphometric and morphologic data were obtained from each valve apparatus: area, basal width and depth of cusps; depth of commissure, perimeter of fibrous ring, presence o f an atrioventricular node of Albini; number and localization of papillary m.; number o f tendinous cords and their relation to the cusps. The area o f the cusp was o b t a i n e d f r o m the o r t h o g o n a l projection on to millimeter squared paper. The width of the base was obtained by measuring the greatest distance between the commissures with a pachymeter. The depth o f the cusp was considered as the greatest distance
between the fibrous ring and the free edge of cusp. The depth of commissure was the smallest distance between the fibrous ring and the free edge of commissure (Fig. 1). These data were used in the following ratios: the area of each cusp to the total area of the valve to which it belongs (the area of each cusp to the total valve area); the basal width of a cusp to the perimeter of the fibrous ring; the depth of the commissure to the depth of a cusp. For localization of the cusps, the atrioventricular fibrous ring was compared with a scaled circle in which the initial point (zero) corresponded to the membranous portion of the interventricular septum. Those cusps usually described in the constitution of the tricuspid valve (anterior, posterior and septal) were considered as habitual ones (Fig. 2). Other cusps occasionally found were named as supernumerary or commissural depending on established criteria,
Results
Area and width o f base The participation of area and basal width of habitual, supernumerary or commissural cusps respectively in the total area of the tricuspid valve and in the perimeter of the fibrous ring was significantly different in each case. Both ratios were greater in habitual than in commissural cups (Tables 1 and 2).
Table 1. Ratio, in percentage, between cusp areas and area of tricuspid valve. Variance of Kmskal-Wallis. Proportion of area: H calculated = 97.65. Dunn's multiple comparison. Significant differences II~, - l~sp = 28.29 (p
Surg Radiol Anat (1990) 12 : 37-41
Journal of Clinical Anatomy
(~) Springer-Verlag 1990
Anatomical study of the human tricuspid valve N Wafae, H Hayashi, LR Gerola and MC Vieira Department of Morphology of the Escola Paulista de Medicina, rua Botucatu 740, 04023-Vila Clementino, S~o Paulo, Brazil 04023
Summary. An anatomical study of the tricuspid valve was carried out in 50 human hearts of both female and male individuals using a m e t h o d of d i s s e c t i o n w h i c h preserves the integrity of the valve. Morphometric criteria such as area of cusp, width of cusp base, relation between commissure depth and cusp depth and morphological criteria such as the presence of atrioventricular cusp node, number of tendinous cords, perimeter of fibrous ring, and properties of papillary m. were adopted for characterization of a cusp. In 64% of cases, commissural cusps were present independent of the number of tricuspid cusps. The tricuspid valve was not consistently tricuspid, but was observed to present 2, 4, 5 or 6 cusps in 72% of cases.
morphom6triques (surface de la cuspide, largeur de la base de cette cuspide, rapport entre la profondeur de la commissure et la profondeur de la cuspide), et aussi des crit6res m o r p h o l o g i q u e s (pr6sence de nodule sur la cuspide atrio-ventriculaire, nombre de cordages tendineux, p6rim6tre de l'anneau fibreux et qualit6 des muscles papiilaires) pour une caract6risation ad6quate des cuspides. Dans 64 % des cas, une valvule avec ses commissures propres 6tait prfsente ind6pendamment des trois cuspides de la valve atrio-ventriculaire droite. Cette valve n'6tait pas toujours tricuspide, mais pr6sentait 2, 4, 5 ou 6 valvules dans 72 % des cas.
Etude anatomique de la valve atrio-ventriculaire droite chez l'homme
The classic description of the tricuspid valve found in the majority of treatise [2-4, 6, 9, 12-14, 17-20] and in specialized works [1, 7, 16] refer to 3 cusps: anterior, septa! and posterior. Some authors also make reference to accessory or commissural cusps [2, 4, 6, 12-14, 18-20] and others admit the existence of different numbers of cusps [8, 21] or subdivided cusps [15]. However, the literature lacks properly established criteria to
R~sum~. Les auteurs ont r6alis6 une 6tude anatomique de la valve atrio-ventriculaire droite sur 50 c0eurs humains des deux sexes partir d'une m6thode de dissection qui pr6serve l'int6grit6 de cette valve. Ils ont utilis6 des crit6res
Offprint requests : N Wafae
distinguish the habitual or supernumerary cusp from a commissural cusp. Embryologically, the division of the common atrioventricular canal into right and left channels ends in the embryo of 40 days. These channels, which are surrounded by mesenchymal subendothelial tissue called endocardial cushions that contribute to the future atriov e n t r i c u l a r v a l v e , grow and straigten approximating the edges of endocardial cushions [5, I1]. The haemodynamic current and the coalescence of spaces among ventricular trabeculated tissue, are mainly responsible for the individualization of cusps of the atrioventricular valves. The aim of this study is to establish morphological and morphometric criteria which might serve as parameters for precise identification of the cusps and fill the existing gap in the literature. Once these parameters are established, this work also defines the number and localization of cusps as well as the presence of supernumerary and commissural cusps. Material and method Fifty human hearts, from male and f e m a l e with no m a c r o s c o p i c evidence of rheumatic and conge-
N Waf~,e ct al: Human tricuspid valve
38
Figs. 1+ 2
1 Photograph of tricuspid valve (after opening of fibrous ring and extension of valve). Representation of measurements: A depth of cusps B depth of nearest commissure from point 0 C depth of farthest commissure from point 0 D width 2 Photograph of tricuspid valve, constituted by 3 cusps: anterior (A). septal (B) and posterior (C), in original position 1 Photographie de la valve atrio-ventriculaire droite (apr~s ouverture de l'anneau fibreux et raise ~tplat de la valve). Mensurations : A profondeur des valvules B profondeur de la commissure la plus proche du point 0 C profondeur de la commissure la plus 61oign6e du point 0 D largeur 2 Photographie de la valve atrio-ventriculaire droite constitu6e par 3 valvules : ant~rieure (A), septale (B), post6rieure (C), dans leur position d'origine
nital lesions or other conditions that could cause alterations to the valve apparatus were selected. Dissection o f the myocardium was carried out from the right atrioventricular fibrous ring to the origin of the papillary muscles, preserving the integrity o f valve apparatus as a whole. Morphometric and morphologic data were obtained from each valve apparatus: area, basal width and depth of cusps; depth of commissure, perimeter of fibrous ring, presence o f an atrioventricular node of Albini; number and localization of papillary m.; number o f tendinous cords and their relation to the cusps. The area o f the cusp was o b t a i n e d f r o m the o r t h o g o n a l projection on to millimeter squared paper. The width of the base was obtained by measuring the greatest distance between the commissures with a pachymeter. The depth o f the cusp was considered as the greatest distance
between the fibrous ring and the free edge of cusp. The depth of commissure was the smallest distance between the fibrous ring and the free edge of commissure (Fig. 1). These data were used in the following ratios: the area of each cusp to the total area of the valve to which it belongs (the area of each cusp to the total valve area); the basal width of a cusp to the perimeter of the fibrous ring; the depth of the commissure to the depth of a cusp. For localization of the cusps, the atrioventricular fibrous ring was compared with a scaled circle in which the initial point (zero) corresponded to the membranous portion of the interventricular septum. Those cusps usually described in the constitution of the tricuspid valve (anterior, posterior and septal) were considered as habitual ones (Fig. 2). Other cusps occasionally found were named as supernumerary or commissural depending on established criteria,
Results
Area and width o f base The participation of area and basal width of habitual, supernumerary or commissural cusps respectively in the total area of the tricuspid valve and in the perimeter of the fibrous ring was significantly different in each case. Both ratios were greater in habitual than in commissural cups (Tables 1 and 2).
Table 1. Ratio, in percentage, between cusp areas and area of tricuspid valve. Variance of Kmskal-Wallis. Proportion of area: H calculated = 97.65. Dunn's multiple comparison. Significant differences II~, - l~sp = 28.29 (p
