Anatomical study of Human Tricuspid Value

Satish Kumar, S (2011) Anatomical study of Human Tricuspid Value. Masters thesis, Madras Medical College, Chennai.

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Abstract

INTRODUCTION: Tricuspid Valve sometimes called the “Forgotten Valve” and a “Second-Class Structure” in Cardiac Surgery. It can be a potential source of considerable morbidity and mortality , both when it is a primary site of disease and when it is secondarily involved in left heart or pulmonary vascular disease. The Tricuspid valve complex consists of functional units which include Tricuspid annulus, valve leaflets, chordae tendineae and papillary muscles. The tricuspid valve annulus is a collagenous ring succeeding the orifice, where the bases of the cusps are attached. The annulus is composed of anterior and posterior rims of collagenous tissue. The leaflets or cusps of tricuspid valve are three in number, named anterior, posterior and septal according to their attachment to the annulus. Anterior leaflet is the largest and septal is the smallest. The junctions between the leaflets are represented by deep indentation or commissures, which are named as the anteroseptal, posteroseptal and anteroposterior commissures. The anterior leaflet is attached to the upper margin of the annulus and extends medially across the membranous part of the ventricular septum to meet the septal leaflet at the anteroseptal commissure. The septal leaflet is attached horizontally to the lower margin of the annulus and extends from antero posterior to postero septal commissures.The septal leaflet extends from the muscular part to the ventricular septum.Each leaflet presents from the free margin to the annulus 3 zones -rough, clear and basal zones. AIM OF THE STUDY: Normal tricuspid valve function depends upon the anatomical and mechanical integrity of the AV ring, the valve leaflets, chordate tendineae and papillary muscles. Advances in echocardiography, invasive cardiology and surgical reconstruction of Tricuspid valves necessitate an appreciation of the many variations in the anatomy of the Tricuspid valve for Interventional Cardiologists and Cardiac Surgeons. The classical description of the tricuspid valve found in the text books of anatomy is inadequate for the need of cardiac surgeon. Similarly the importance of the valvular structures and the myocardium in the mechanism of valve closure requires a new appraisal in view of recent observations. Numerous variations in the configuration of the cusp tissue and chordal/papillary support of the tricuspid valve, making the interior of the right ventricle as unique to each individual as one’s finger print. The aim of the present study is to analyse the morphological and morphometric details of the human tricuspid valve complex. MATERIALS AND METHODS: STUDY MATERIALS: 1. Heart from 45 adult cadavers. 2. Fetal heart from 5 dead fetus. 3. Adult 2 dimensional Echocardiogram. METHODS OF STUDY: A. Dissection method: • Conventional dissection method. B. Radiological study: • Adult 2D Echocardiogram Study. SPECIMEN COLLECTION: 1. Forty five adult embalmed human cadavers were selected from the cadavers allotted to the first MBBS students and first BDS students at the Institute of Anatomy, Madras Medical College, Chennai-3. 2. Five dead unclaimed fetuses were obtained from the Institute of Obstetrics and Gynaecology, Egmore. Fetal embalming was done by injecting 200 ml of embalming fluid consisting of formalin, glycerol, alcohol and thymol, through the aorta. CONCLUSION: The Tricuspid valve which guards right atrioventricular orifice was studied in detail by conventional dissection and radiological (echocardiogram) method. The shape and circumference of tricuspid valve annulus, number and length of commissures, number, shape, height and length of tricuspid leaflets, types of chordae tendineae, number of chordae tendineae at origin and insertion, papillary muscle and its numbers have been observed and correlated with the findings of already existing studies. The following conclusions are derived from these parameters:- • The shape of the Tricuspid annulus were circular in 39 heart specimens (86.7%) and oval in 6 heart specimens (13.3%). • The circumference of the tricuspid annulus ranged from 10.3cm-13 cm and the mean circumference was found to be 11.8 cm. • The number of commissures in 36 hearts were 3 in number namely AP ,PS and AS commissure. 9 heart specimens with accessory leaflets presented with accessory commissures. • The average length of AP commissure was 1.17cm (range 0.9-1.4 cm) and average length of PS commissure was 0.74cm (range 0.6-0.9 cm).The average length of AS commissure was 0.64cm (range 0.5-0.9 cm). • The number of leaflets in tricuspid valve of 36 hearts were found to be 3 in number (80%). 4 leaflets were found in 6 hearts (13.5%), 5 leaflets in one heart (2.2%) and 6 leaflets in 2 hearts (4.4%). • The shape of the anterior , posterior leaflets were triangular in all the 45 hearts (100%). The septal leaflets were triangular in 42 hearts (93.3%) and semicircular in 3 hearts (6.7%). • Accessory leaflets found in 9 hearts (20%) having 4 , 5 and 6 leaflets and all were triangular in shape. Two types of accessory leaflets, spurious and true accessory leaflet were identified. • Two types of foramina were found in tricuspid valves. True natural foramina were present in 3 hearts and spurious foramina in 9 hearts. • The height of the anterior leaflet ranged from 1.9 – 2.5 cm (mean 2.21 cm), septal leaflet 1.4-1.9cm (mean 1.68 cm) and posterior leaflet 1.7-2.2 cm (mean 1.92 cm). • The length (width) of the anterior leaflet varied from 3.0 – 3.9 cm (mean 3.51cm), septal leaflet 2.8-3.9cm (mean 3.26 cm) and posterior leaflet 2.0-3.2 cm (mean 2.5 cm). • The height of the accessory leaflet ranged from 0.6 – 1.4 cm (mean 0.95 cm) and length (width) of the accessory leaflet varied from 0.7 – 1.4 cm (mean 1.08 cm). • All 5 types of chordae namely Rough Zone Chordae, Commissural chordae, Free edge chordae, Deep and Basal chordae were present in the present study. • The number of chordae tendineae originated from APM ranged from 3 to 10 (mean 5.7) and from SPM ranged from 0 to 8 (mean 3.71). The number of chordae tendineae originated from PPM ranged from 1 to 8 (mean 3.75 ). In 10 hearts there were no SPM and in these 10 hearts the chordae tendineae directly arose from ventricular wall. • The number of chordae tendineae inserted into anterior leaflet ranged from 9 to 21 (mean 14.2) and in septal leaflet the number ranged from 7 to 18 (mean 11.95).The number of chordae tendinae inserted into posterior leaflet ranged from 8 to 16 (mean 9).3to6 chordae tendinae were inserted into the commissures and clefts. • The anterior and posterior papillary muscles were present in all the 45 hearts (100%).The septal papillary muscles presented only in 35 hearts ( 77.8%). • The APM was presented with one head (belly) in 37 hearts, 2 heads in 7 hearts and 3 heads in 1 heart. • The SPM were absent in 10 hearts ,presented with one head in 7 hearts , 2 heads in 14 hearts ,3 heads in 10 hearts and 4 heads appeared in 4 hearts. • The posterior papillary muscle presented with one head in 17 hearts, 2 heads in 20 hearts, 3 heads in 8 hearts. Based on this study, I hereby conclude that the "Anatomical study of Human Tricuspid Valve " is composed of variations in the shape, circumference of tricuspid annulus, number and length of commissures, number, shape, height and length of tricuspid valve leaflets ,chordae tendineae and papillary muscle. Hence I hope that this study would be of great use to the cardiologist and cardiac surgeons, in echocardiography, interventional cardiology and in surgical reconstruction of Tricuspid valves. The morphometric analysis of the valve is useful for the cardiac surgeons to determine the size of the prosthetic valves in valve replacement, annuloplasty, commissurotomy, and artificial chordae tendineae replacement.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Human Tricuspid Value, Anatomical study.
Subjects: MEDICAL > Anatomy
Depositing User: Subramani R
Date Deposited: 09 Jul 2020 11:37
Last Modified: 09 Jul 2020 11:37
URI: http://repository-tnmgrmu.ac.in/id/eprint/12514

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