- Received June 24, 2021
- Accepted June 28, 2021
- Publication October 01, 2021
- Visibility 3 Views
- Downloads 0 Downloads
- DOI 10.18231/j.ijcap.2021.050
-
CrossMark
- Citation
A cadaveric study on chordae tendinae of human tricuspid valve
- Author Details:
-
Harsha B R
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Chandragirish S *
-
Girish V Patil
Introduction
The opening of a new field of surgical endeavour often arouses interest in the detailed study of the anatomy of the involved part of the body. As a result of such studies, current notions may be changed and extended so as to understand better. The impetus given to tricuspid valve surgery in the course of the last few years has prompted revision of our knowledge concerning the anatomy of the normal. In present study the number and types of chordae tendinae in tricuspid valve were studied and then compared with the works of many eminent scientists in this field.
The atrioventricular valvular complex in both right and left ventricles consists of the orifice and its annulus, the cusps, the supporting chordae tendinae of various types and the papillary muscles. Tricuspid valve is made up of six major components like Right atrial wall, Annulus, Three leaflets, Chordae tendinae, Papillary muscles, Right ventricular free wall.
Harmonious interplay of all these, together with the atrial and ventricular myocardial masses depends on the conducting tissues and the mechanical cohesion provided by the fibro elastic cardiac skeleton.
All parts change substantially in position, shape, angulation and dimensions during a single cardiac cycle. The tendinous chords are fibrous collagenous structure covered by endothelial lining supporting the valve leaflets.
Chordae tendinae are small thread like structures originated from a papillary muscle either directly from the apex of the muscle or from small nipples, which were usually on their upper third. The chordae were attached to the ventricular end of the valve leaflets and their apices and margins and then, anchored to the muscular ventricular wall.[1]
They were classified by Tandler into I, II and III order chordae but morphologically various types have been described, they are:
Fan shaped chordae
They have a short stem from which branches radiate to attach to the tip (margin), other zones of apposition between leaflets and to the ends of adjacent leaflets, on their ventricular aspect.
Rough zone chordae
Arise from a single stem, which usually splits, into three components, which attach to the free margin and to some intermediate point on the leaflet, on the ventricular aspect.
Free edge chordae
They are single, thread like and often long, passing from either the apex or base of a papillary muscle to a marginal attachment, usually near the midpoint of a leaflet or one of its scallops.
Deep chordae
Round or flat ribbons, long and slender or short and muscular. They arise from the smooth or trabeculated ventricular wall and attach to the basal component of a leaflet.
Basal chordae
Small, flat ribbons structure extends from the ventricular wall to the basal zones of the leaflets.
Normal function of tricuspid valve depends on the anatomic and mechanical integrity of the chordae tendinae. This study will be much help for surgical procedures like chordal replacement, tightening of valve leaflets in tricuspid valve prolapse. Ruptured chordae tendinae will be the cause for myocardial infarction and arrhythmia.[2]
Materials and Methods
The present cross sectional study was conducted at CIMS Chamarajanagara from January 2017 to December 2018. The study was carried out on 96 formalin fixed human hearts from patients who had died of non- to December vascular causes and were autopsied. No gross abnormality of the tricuspid valves was noted. Study was done without any grouping of specimens on the basis of sex and age. Dissection was performed according to standard autopsy techniques. The Tricuspid valve was opened by a scalpel knife cut passing from the right atrium to the apex of the right ventricle through the lateral or acute margin of the ventricle. The interior of the heart was washed and all the blood clots were removed. The second cut was made along the anterior surface of the heart just left to the intra-ventricular groove from apex of the ventricle to annulus; care was taken not to damage the papillary muscles. After opening the valve from ventricular side, blood clots were removed completely, types of chordae tendinae observed according to its morphology and attachments and photographed after the approval from the Ethical Committee.
The data were summarised using descriptive statistics like frequency (number of chordae tendinae) and discrete variable (types of chordae tendinae) were measured by proportions. All the statistical calculations were performed using software SPSS for windows {Statistical Package for Social Service (SPSS) Inc, 2004, New York} version 13.0.
Observations and Results
In present study number of chordae tendinae in a tricuspid valve ranges from 4 to 19. Most commonly observed were 11 chordae tendinae in 16 hearts. Maximum number is 19 chordae tendinae observed in 2 hearts and minimum number is 4 chords in 1 heart specimen. Average number of chordae tendinae attached to each papillary muscle was as follows: 1-9 chordae tendinae originated from the anterior papillary muscle, 1-6 from the posterior papillary muscle and 1-4 from septal papillary muscle.
5 types of chordae tendinae were observed namely fan shaped, free edge, rough zone, basal and deep.
In 130 anterior papillary muscle observed, fan shaped chordae present in 20 muscles with range of 1 to 3 per muscle, free edge chordae present in 105 muscles with range of 1 to 4 per muscle, rough zone chordae present in 83 muscles with range of 1 to 3 per muscle, basal chordae present in 69 muscles with range of 1 to 2 per muscle and deep chordae present in 53 muscles with range of 1 to 3 per muscle.
|
Shape of Anterior Papillary Muscle |
Frequency |
|
Fan Shaped |
20 |
|
Free Edge Shaped |
105 |
|
Rough Zone Shaped |
83 |
|
Basal Chordae |
69 |
|
Deep Chordae |
53 |
In 211 posterior papillary muscle observed, fan shaped chordae present in 22 muscles with range of 1 to 3 per muscle, free edge chordae present in 152 muscles with range of 1 to 3 per muscle, rough zone chordae present in 67 muscles with range of 1 to 3 per muscle, basal chordae present in 46 muscles with range of 1 to 3 per muscle and deep chordae present in 58 muscles with range of 1 to 2 per muscle.
|
Shape of Posterior Papillary Muscle |
Frequency |
|
Fan Shaped |
22 |
|
Free Edge Shaped |
152 |
|
Rough Zone Shaped |
67 |
|
Basal Chordae |
46 |
|
Deep Chordae |
58 |
In 77 septal papillary muscle observed, fan shaped chordae present in 48 muscles with range of 1 to 2 per muscle, free edge chordae present in 40 muscles with range of 1 to 2 per muscle, rough zone chordae present in 10 muscles with 1 per muscle, basal chordae present in 12 muscles with range of 1 to 2 per muscle and deep chordae present in 17 muscles with range of 1 to 2 per muscle.
|
Shape of Septal Papillary Muscle |
Frequency |
|
Fan Shaped |
48 |
|
Free Edge Shaped |
40 |
|
Rough Zone Shaped |
10 |
|
Basal Chordae |
12 |
|
Deep Chordae |
17 |
Discussion
In the present study range of Chordae Tendinae in papillary Muscle was seen in the range of 2-9 in APM, 1-6 in PPM and 1-4 IN SPM. The Chordae Tendinae seen in other studies done by Balachandra N[3] et al. (1-8 APM, 1-6 PPM and 1-9 SPM), Gerola L R et al[4] (3-8 APM, 2-6 PPM and 5-8 SPM), Nigri GR[5] et al.(1-11 APM, 1-8 PPM and 1-5 SPM), Motabagani MBM[6] (11-13 APM, 5-7 PPM and 6-11 SPM), Kocak A[7] et al (2-7 APM, 1-6 PPM and 1-4 SPM), Skwarek M[8] et al (8-18 APM, 5-16 PPM and 9-11 SPM), Skwarek M[2] et al (3-4 APM, 3-4 PPM and 2-4 SPM), Silver MD[9] et al (2-7 APM, 2-6 PPM and 2-9 SPM).
Observation regarding the number of chordae tendinae in Tricuspid valve in the present study was not in agreement with the any of the work, every work has its own value. Possible reason for these differences would be number of specimens studied and geographical place of the specimens. This shows high variability of number in chordae tendinae arrangement.
The flexibility of particular leaflets of the Tricuspid valve varies, as does the tension of the blood stream in particular cusps. The study of the distribution of tendinous chords of the Tricuspid valves is helpful in aspects of progress in cardio surgical techniques, including Tricuspid valve repair with chordal replacement after traumatic regurgitation, surgical repair of the mitral and Tricuspid valve simultaneously using the De Vega method and invasive procedure with balloon valvuloplasty in cases of stenosis.[2]
The ramification of chords attaching septal leaflets was higher than for the anterior and posterior leaflets. This, as well as the morphology of the septal papillay muscles, may be related to the lower mobility of the septal cusp than others. In the present study five types of chordae are identified which are similar to the studies by Silver MD et al., Kocak A et al. and Balachandra N et al.
Comparison of this observation with studies of above mentioned authors as follows:
Observation regarding the range of fan shaped chordae tendinae in papillary muscles in the present study was in agreement with the work of Balachandra N et al.[3] (0-7 APM, 0-5 PPM, 0-4 SPM) Observations are showing much difference between present study and work done by Kocak A et al.[7] (0-2 PPM) and Silver MD et al.[9] (0-2 PPM)Possible reason for such difference is the number of specimens studied.
|
S. No. |
Studies |
No. cases studied |
Range of FE chordae tendinae in papillary muscles |
||
|
APM |
PPM |
SPM |
|||
|
1 |
Present study |
96 |
0-4 |
0-3 |
0-2 |
|
2 |
Balachandra N [3] et al. |
96 |
0-5 |
0-5 |
0-4 |
|
3 |
Kocak A[7] et al. |
400 |
0-2 |
0-4 |
0-4 |
|
4 |
Silver MD[9] et al. |
50 |
0-2 |
0-4 |
0-4 |
Observation regarding the range of free edge chordae tendinae in papillary muscles in the present.
study was in agreement with the work of Balachandra N et al.[3] (0-5 APM, 0-5 PPM, 0-4 SPM).
But, number of chordae tendinae from APM in the present study was ranged from 0-5.
Observations are showing much difference between present study and work done by Kocak A et al.[7] (0-2 APM, 0-4 PPM, 0-4 SPM) and Silver MD et al.[9] (0-2 APM, 0-4 PPM, 0-4 SPM).
Possible reason for such difference is the number of specimens studied.
Observation regarding the range of rough zone chordae tendinae in papillary muscles in the present study was in agreement with the work of Balachandra N et al.[3] (0-4 APM, 0-3 PPM, 0-5 SPM). But, number of chordae tendinae from SPM in the present study was ranged from 0-5. Observations are showing much difference between present study and work done by Kocak A et al.[7] (2-6 APM, 0-4 PPM, 2-7 SPM) and Silver MD et al.[9] (2-6 APM, 0-5 PPM, 2-6 SPM). Possible reason for such difference is the number of specimens studied.
Observation regarding the range of basal chordae tendinae in papillary muscles in the present study was in agreement with the work of Balachandra N et al.[3] (0-3 APM, 0-2 PPM, 0-2 SPM). Observations are showing much difference between present study and work done by Kocak A et al. [7] (0-3 APM, 0-5 PPM, 1-6 SPM).and Silver MD et al.[9] (0-3 APM, 0-5 PPM, 0-6 SPM). Possible reason for such difference is the number of specimens studied.
Observation regarding the range of deep chordae tendinae in papillary muscles in the present study was in agreement with the work of Balachandra N et al[3] (0-3 APM, 0-2 PPM, 0-3 SPM). Observations are showing much difference between present study and work done by Kocak A et al[7] (0-5 APM, 0-5 PPM, 0-5 SPM) and Silver MD et al.[9] (0-5 APM, 0-5 PPM, 0-4 SPM). Possible reason for such difference is the number of specimens studied.
Conclusion
The present study to understand the anatomy of the constituent parts of the tricuspid valve complex not only helped examination of these parts in cross sectional interrogation but also enhanced appreciation of valvular anomalies. Free edge and deep chordae are unique to the Tricuspid valve. The deep chordae seem to provide a second arcade of leaflet attachment which is not found in the mitral valve. Possibly this is needed because of the larger valve annulus and the larger veil of leaflet tissue that descends into the ventricular cavity. Regurgitation is a consequence of deformity, shortening and retraction of one or more leaflets of the Tricuspid valve as well as shortening and fusion of the chordae tendinae and papillary muscles.
Source of Funding
None.
Conflict of Interest
The authors declare no conflict of interest.
References
- S Standring, NR Borley, P Collins, AR Crossman, MA Gatzoulis, JC Healy. The Anatomical Basis of Clinical Practice. Gray’s Anatomy 2008. [Google Scholar]
- M Skwarek, J Hreczecha, M Dudziak, J Jerzemowski, M Grzybiak. The morphology and distribution of the tendinous chords and their relation to the papillary muscles in the Tricuspid valve of the human heart. Folio Morphol 2007. [Google Scholar]
- N Balachandra, BPP Rathnam. Study of the dimensions of the Human Tricuspid valve and attachment of chordaetendinae. . [Google Scholar]
- LR Gerola, N Wafae, MC Vieira, Y Juliano, R Smith, JC Prates. Anatomic study of the Tricuspid valve in children. Surg Radiol Anat 2001. [Google Scholar]
- GR Negri, LJA Didio, CAC Baptista. Papillary muscles and tendinous chords of the right ventricle of the human heart morphological characteristics. Surg Radiol Anat 2001. [Google Scholar]
- MAB Motabagani. Comparative, morphometric and histological studies of the Tricuspid valve complex in human and some mammalian hearts. J Anat Soc India 2006. [Google Scholar]
- A Kocak, F Govsa, EO Aktas, B Boydak, IC Yavuz. Structure of the human Tricuspid valve leaflets and its chordae tendinae in unexpected deaths: A forensic autopsy study of 400 cases. Saudi Med J 2004. [Google Scholar]
- M Skwarek, M Dudziak, J Hreczecha, M Grzybiak. The connection between the papillary muscles and leaflets of the Tricuspid valve. Folia Morphol 2006. [Google Scholar]
- MD Silver, JHC Lam, N Ranganathan, ED Wigle. Morphology of the human Tricuspid valve. Circulation 1971. [Google Scholar]