|Year : 2022 | Volume
| Issue : 4 | Page : 324-328
Case report of persistent left superior vena cava with absent papillary muscle – Unusual coexistence
Divya Umamaheswaran, Jayagandhi Sakkarai, Rema Devi
Department of Anatomy, Pondicherry Institute of Medical Sciences, Puducherry, India
|Date of Submission||28-May-2022|
|Date of Decision||13-Jul-2022|
|Date of Acceptance||25-Jul-2022|
|Date of Web Publication||01-Dec-2022|
Dr. Divya Umamaheswaran
Department of Anatomy, Pondicherry Institute of Medical Sciences, Puducherry - 605 014
Source of Support: None, Conflict of Interest: None
Persistent left superior vena cava (PLSVC) is uncommon with an incidence of 0.3%–1.3%. The incidence of absent papillary muscle is unknown. Congenital anomalies of a thoracic venous system associated with absent papillary muscle are very rare. During dissection of a 55-year-old male cadaver, PLSVC with absent papillary muscle was found. Although these congenital anomalies are incidentally found, it is worthwhile following such patients to look for the evolution of any cardiac symptoms. Sound knowledge and awareness of such congenital anomalies are required for radiologists, cardiothoracic surgeons, and critical care physicians.
Keywords: Heart failure, papillary muscle, tricuspid regurgitation
|How to cite this article:|
Umamaheswaran D, Sakkarai J, Devi R. Case report of persistent left superior vena cava with absent papillary muscle – Unusual coexistence. J Anat Soc India 2022;71:324-8
|How to cite this URL:|
Umamaheswaran D, Sakkarai J, Devi R. Case report of persistent left superior vena cava with absent papillary muscle – Unusual coexistence. J Anat Soc India [serial online] 2022 [cited 2023 Jan 27];71:324-8. Available from: https://www.jasi.org.in/text.asp?2022/71/4/324/362556
| Introduction|| |
Congenital anomalies of the thoracic venous system are uncommon. These anomalies are commonly encountered incidentally, yet the knowledge of them is necessary for the prevention of misdiagnosis. Superior vena cava (SVC) is the second-largest valveless vein in the human body. It is located in the anterior right superior mediastinum with a length measuring 7 cm and a width of 24 mm. SVC is formed by the union of the right and left brachiocephalic veins, and finally, drains into the right atrium. It extends from the confluence of the brachiocephalic veins behind the first right costal cartilage, and at the level of the second costal cartilage, SVC enters the middle mediastinum piercing the fibrous pericardium and eventually drains into the right atrium, at the level of third right costal cartilage. The main function of the SVC is to drain the blood from the upper half of the body above the diaphragm into the right atrium. SVC receives tributaries from the left and right brachiocephalic veins and azygos veins. The minor tributaries such as mediastinal veins, esophageal veins, and pericardial veins drain into the azygos vein. SVC is considered to be an ideal site for the insertion of a central venous catheter for monitoring fluid levels, especially when peripheral veins are difficult to access, in patients admitted to the intensive care unit. Variant anatomy of the SVC can lead to misplacement of central venous catheter leading to serious complications in the patient. Sound knowledge of normal anatomy and the possible variations of SVC are necessary for clinicians and radiologists.
Double SVC is an infrequent variation of the venous system. In double SVC, the most common type is persistent left superior vena cava (PLSVC), but in the general population, its incidence is reported to be around 0.3%–1.3% only.,, The prevalence increases up to 11% when it is associated with other congenital cardiac abnormalities. Although most individuals do not encounter any problems, rarely it can cause tricuspid regurgitation leading to heart failure clinically.
Papillary muscles are pillar-like muscles present in the ventricles of the heart. It attaches the cusps to the ventricular wall by chordae tendineae. The main function is to help in the tight closure of the atrioventricular valves during the systole phase. The absence of papillary muscle is an uncommon variation with unknown prevalence. Tricuspid regurgitation can be caused due to decrease in the number of the papillary muscles in the ventricles.
Numerous double SVC with congenital cardiac anomalies cases have been reported earlier. However, a congenital anomaly with double SVC associated with absent papillary muscle has not been reported, and to the best of our knowledge, it is the first report from a cadaver.
| Case Report|| |
During routine dissection of an adult male cadaver of approximately 55 years, in the Department of Anatomy in Pondicherry Institute of Medical Sciences, on opening the thoracic cavity, two veins entering the heart were noted. Further dissection was done, and the presence of double SVC (right and PLSVC) was confirmed as shown in [Figure 1]a and [Figure 1]b.
|Figure 1: (a) Double SVC with heart in situ and pulmonary arteries removed. (b) Superior view of the heart showing double SVC. (c) Formation of both SVC with oblique communication. (d) Dilated coronary sinus. SVC: Superior vena cava|
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Venous system variation
The PLSVC was narrower (17 mm) than the right element. There was no variation in the length of both SVC (69 mm). The right SVC was draining into the right atrium directly and had a normal diameter of about 25 mm. It was seen as the continuation of a right brachiocephalic vein which was formed by the confluence of the right internal jugular vein and right subclavian vein. The right internal jugular vein, measuring 26 mm in diameter, was dilated. The formation of both SVC and right IJV dilatation is shown in [Figure 1]c. The left SVC was formed as a continuation of the left brachiocephalic vein. A confluence of the left internal jugular and left subclavian vein led to the formation of the left brachiocephalic vein. The coronary sinus was receiving the left SVC in the superior border and draining into the right atrium. Since the coronary sinus was receiving an additional venous channel, it was found to be dilated, measuring 17 mm, as shown in [Figure 1]d. A venous channel which acts as a communication between the right and left SVC called oblique communication during embryogenesis was observed between the left and right SVC. It was noted below the sternal angle, 60 mm below the thyroid cartilage, and 20 mm above the aortic arch. It was narrow measuring about 9 mm in diameter.
Inferior vena cava (IVC), azygos and hemiazygos vein formation and drainage were noted. IVC formation and drainage were normal, but IVC was dilated significantly (30 mm diameter). Azygos formation and drainage were normal. The hemiazygos formation was normal, but it was draining into the left persistent SVC.
No anomalies were observed in the arterial system. The brachiocephalic trunk, common carotid artery, and left subclavian were arising from the aortic arch directly. The thoracic duct, vagus nerve, and sympathetic trunks were noted to be normal.
Variations in the heart
On exploratory dissection of the interior of the heart, the right auricle and right atrium were found to be enlarged. Dilatation of coronary sinus opening was observed. The left atrium appeared normal and four pulmonary veins were draining into it. There were no defects in the interatrial septum. The tricuspid valve appeared patulous and dilated, with the orifice measuring 45 mm × 30 mm in diameter, and with a surface area of about 10.5 cm2 [Figure 2]a. Mitral orifice and mitral valves were normal. The right ventricular wall was thin. The thickness of the wall was 5 mm. Only anterior papillary muscle of ventricle was noted and appeared to be thin; thickness measured only 3 mm [Figure 2]b. Posterior and septal papillary muscles were absent. The moderator band was present, but it was very thin measuring 2 mm in thickness. The thickness of the left ventricle was normal, measuring about 20 mm. The anterior and posterior papillary muscles were present [Figure 2]c. No defects were noted in the interventricular septum. On comparing the thickness of the right ventricle and left ventricle, the left ventricle was found to be four times thicker than the right ventricle which implies that there is a significant right ventricular wall dilatation.
|Figure 2: (a) The interior of the right atrium with dilated coronary sinus ostium and patulous tricuspid valve. (b) Thinned right ventricular wall and the yellow arrow show the anterior papillary muscle. (c) The interior of the left ventricle and red arrow showing anterior and posterior papillary muscles|
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Classifications of double superior vena cava
Numerous classifications have been proposed for double SVC based on the presence or absence of the right SVC, presence or absence of the anastomotic venous channel between the right and left SVC, and presence or absence of the paired azygos vein and in association with congenital heart diseases. In combination with all these three criteria, Uemura et al. concluded with 24 types of DSVC. Although these classifications provide a better understanding, considering the importance of the drainage pattern of the left SVC, Zhang et al. recently proposed a newer classification based on the presence or absence of the left brachiocephalic vein and drainage pattern of the left SVC.
Zhang et al.'s Classification
- Type I – LBCV absent, LSVC drains into the right atrium via the coronary sinus
- Type II – LBCV present, LSVC drains into the right atrium via the coronary sinus
- Type III – LBCV absent, LSVC drains into the right atrium via anastomosis
- Type IV – LBCV present, LSVC drains into the right atrium via anastomosis.
If the LSVC drains into the left atrium, it is classified as others.
Type II was found to be more prevalent than other types. This classification would also provide a better vision for clinicians to understand the hemodynamic changes better in case of a double SVC anomaly.
| Discussion|| |
In most instances, double SVC is incidentally encountered. Mc Cotters reported the first case of double SVC in 1918. About 80%–90% of PLSVC drains into the coronary sinus but 10%–20% drains into the left atrium. This case reports double SVC with the presence of oblique connection between two SVC and also with an interesting finding of the absence of papillary muscle of the right ventricle. Schematic representation of which is shown in [Figure 3]. As per Zhang et al. classification, this anomaly can be classified as Type II with the additional presence of oblique connection making it an exceptional report. In literature, the absence or presence of one papillary muscle in the left ventricle is reported so far. However, the absence or presence of one papillary muscle in the right ventricle is not reported. There are multiple congenital anomalies and abnormalities noted in this case which is very uncommon. PLSVC can be attributed to the failure of regression of the left anterior cardinal vein, around 8 weeks of intrauterine life. An oblique connection was found which was serving as a communicating venous channel between the right and left SVC. After the regression of the left anterior and left common cardinal vein, this oblique connection is transformed into the future left brachiocephalic vein. However, the failure of regression of the above led to the persistence of this oblique connection, which is very rare in the case of PLSVC. Another congenital anomaly observed is an absence of posterior and septal papillary muscle in the right ventricle which is due to the failure of formation of trabecular cord from the ventricular surface, around 7–19 weeks.
In this case, there are also some evident features of right heart failure such as enlargement of the right atrium, right ventricle, dilatation of the right internal jugular vein, and IVC which are all due to the presence of the abovementioned congenital anomalies. PLSVC draining into the coronary sinus has caused coronary sinus dilatation. Coronary sinus was draining into the right atrium which caused an overload in the right atrium leading to enlargement. The absence of posterior and septal papillary muscle in the right ventricle caused improper closure of the valve leading to loss of patency of the tricuspid valve. A patulous valve and overloaded right atrium may have caused tricuspid regurgitation which explains the right ventricular dilatation as evidenced by the thinning of the right ventricular wall. Eventually, it led to heart failure as was seen by the right internal jugular vein and IVC dilatation. Since persistent left superior vena and absent papillary muscle can account for tricuspid regurgitation,, in this case, this combined congenital anomaly caused heart failure which is evident by the features. Flowchart explaining the findings of heart failure is shown in [Figure 4].
|Figure 4: Flowchart explaining evident features of heart failure (tricuspid regurgitation)|
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Heart embryogenesis starts around 3 weeks. NK 2 is the master gene for the development of the heart. It is expressed by combined activity bone morphogenetic protein (BMP 3) expression and suppression of WNT. A defect in the NK 2.5 gene would have caused improper development of the heart leading to failure of development of papillary muscle. Venous development is regulated by notch signaling which upregulates the expression of the EPHD 4 gene, which is responsible for the development of veins. Alterations in the expression would have led to anomalies in the thoracic venous system. Development of the venous system and papillary muscle is around 5–19 weeks. Some disturbance in the process of organogenesis during around 5–19 weeks might have caused these multiple congenital anomalies.
| Conclusion|| |
Although many PLSVC case reports are reported earlier, to the best of our knowledge, this is the first cadaveric case report showing PLSVC associated with absent papillary muscle with evident features of tricuspid regurgitation and heart failure. To conclude, persistent double SVC in most of the instances found incidentally, those patients can be followed up to diagnose and prevent heart failure in future. Knowledge and awareness of anatomical variation of SVC and papillary muscle are required for radiologists to prevent misdiagnosis, cardiothoracic surgeons, and critical care physicians for better patient management.
The authors sincerely thank those who donated their bodies to science so that anatomical research could be performed. Results from such research can potentially increase humankind's overall knowledge that can then improve patient care. These body donors and their families deserve our highest gratitude. The authors also thank all the faculties of the department of anatomy and the nonteaching staff of the department.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Schummer W, Schummer C, Fröber R. Persistent left superior vena cava and central venous catheter position: Clinical impact illustrated by four cases. Surg Radiol Anat 2003;25:315-21.
Perles Z, Nir A, Gavri S, Golender J, Tashma A, Ergaz Z, et al.
Prevalence of persistent superior vena cava and association with congenital heart anomalies. Am J Cardiol 2013;112:1214-8.
Nagasawa H, Kuwabara N, Goto H, Omoya K, Yamamoto T, Terazawa A, et al.
Incidence of persistent left superior vena cava in the normal population and in patients with congenital heart diseases detected using echocardiography. Pediatr Cardiol 2018;39:484-90.
Peltier J, Destrieux C, Desme J, Renard C, Remond A, Velut S. The persistent left superior vena cava: Anatomical study, pathogenesis and clinical considerations. Surg Radiol Anat 2006;28:206-10.
Eldin GS, El-Segaier M, Galal MO. High prevalence rate of left superior vena cava determined by echocardiography in patients with congenital heart disease in Saudi Arabia. Libyan J Med 2013;8:21679.
Tian C, Pan S. Congenital absence of anterior papillary muscle of the tricuspid valve and surgical repair with artificial chordae. Interact Cardiovasc Thorac Surg 2017;24:299-300.
Nandy K, Blair CB Jr. Double superior venae cavae with completely paired azygos veins. Anat Rec 1965;151:1-9.
Steinberg I, Dubilier W Jr., Lukas DS. Persistence of left superior vena cava. Dis Chest 1953;24:479-88.
Uemura M, Suwa F, Takemura A, Toda I, Morishita A. Classification of persistent left superior vena cava considering presence and development of both superior venae cavae, the anastomotic ramus between superior venae cavae, and the azygos venous system. Anat Sci Int 2012;87:212-22.
Zhang L, Ling G, Gang Y, Yang Z, Lu Z, Gan X, et al.
Classification and quantification of double superior vena cava evaluated by computed tomography imaging. Quant Imaging Med Surg 2022;12:1405-14.
Goyal SK, Punnam SR, Verma G, Ruberg FL. Persistent left superior vena cava: A case report and review of literature. Cardiovasc Ultrasound 2008;6:50.
Dinasarapu CR, Adiga GU, Malik S. Recurrent cerebral embolism associated with indwelling catheter in the presence of anomalous neck venous structures. Am J Med Sci 2010;340:421-3.
Baird CW, Bengur AR, Bensky A, Watts LT. Congenital absence of posteromedial papillary muscle and anterior mitral leaflet chordae: The use of three-dimensional echocardiography and approach in complex pediatric mitral valve disease. J Thorac Cardiovasc Surg 2010;139:e75-7.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]