sabita singh - njbmsnjbms.in/uploads/19/6330_pdf.pdf · 107 original article sabita singh1,...

107

Original Article

1 2 3Sabita Singh , Parineeta Suman , A.David Ebenezer

INTRODUCTION:

he precise anatomical knowledge of

vascular system anomalies is essential Tdue to its significance in different

developmental problems in adventant and injury in

various invasive procedures. Normal anatomy

describes the formation of a single superior

venacava by the union of right and left

brachiocephalic veins which drains the blood from

upper part of the body.

Superior vena cava anomalies are caused by variations in the development of the embryonic thoracic venous system. The anomalies that involve the superior vena cava include the persistent left superior vena cava with or without the right supe-rior vena cava, absence of superior vena cava, hypoplasia of the superior vena cava, and abnormal opening of the superior vena cava into the left atrium, coronary sinus, azygous venous system,

1and the pulmonary vein.

Persistent left superior vena cava (PLSVC) occurs

as a result of failure of regression of left anterior

Address for correspondence:

Dr. Parineeta Suman,2C, Kaveri Block, Velammal Medical College, Anuppanadi, Madurai- 625009E-mail : [email protected] Mobile : 9159969772

1Asst. Professor, Dept. of Anatomy, Veer Surendra Sai Institute of Medical Science & Research, Sambalpur, Odisha- 7680172Associate Professor, Department of Anatomy, Velammal Medical College, Madurai, Tamilnadu - 625009, India3Assistant Professor, Department of Anatomy, Velammal Medical College, Madurai, Tamilnadu - 625009, India

A Cadaveric Study of Double Superior Vena Cava with Paired Azygos Vein & its Clinical Implications

http://dx.doi.org/10.31975/NJBMS.2019.9301

ABSTRACT

Introduction: Double superior vena cava with a Persistent Left Superior Vena Cava (PLSVC) is an

uncommon abnormality but is the most common thoracic venous anomaly in the setting of SVC. It is

estimated to occur in 0.3- 0.5% of the general population and 3-10% of patients with other forms of

congenital heart disease. The present study aimed to find the frequency of double superior vena

cava, its embryological basis and to correlate its clinical significance.

Materials and methods: The present study, a descriptive study includes sixty cadavers allotted for

first year MBBS students in Department of Anatomy at Velammal Medical College, Madurai during

year 2013-2018. Superior vena cava along with other veins had been traced and studied in detail.

Results : Double superior vena cava was found in 2 cadavers out of 60 cadavers (3.33%). Persistent

left superior vena cava opened into an enlarged coronary sinus that further drained into the right

atrium in both the cases. Left brachiocephalic vein was present in one of them and left azygos vein

ran upward along the left side of vertebral column and drained into PLSVC in the cadaver. There

was no anastomosis between azygos and hemiazygos vein.

Conclusion : Persistent left superior vena cava (PLSVC) occurs as a result of failure of regression of

left anterior cardinal and left common cardinal veins. The precise knowledge of double superior

vena cava by surgeons, sonographers and interventional radiologists can prevent possible

complications in routine clinical practice and during cardiopulmonary bypass.

Key words : Double superior vena cava, Persistent left superior vena cava, Left azygos vein,

Anterior cardinal vein, Coronary sinus

National Journal of Basic Medical Sciences | Volume 9 | Issue 3 | 2019

108

College, Madurai during year 2013-2018. The

mode of formation and drainage of persistent left

superior vena cava along with other thoracic veins

have been properly traced and studied in detail.

RESULTS

We found the presence of persistent left superior

vena cava among 2 cadavers out of 60 cadavers

(3.33%). Persistent left superior vena cava was

observed in adult male cadaver aged 50 years and

adult female cadaver aged 55 years.

Case 1- Adult male cadaver aged 50 years:

Persistent left superior vena cava was formed by

the union of left internal jugular vein and left

subclavian vein. Left brachiocephalic vein was

absent. Persistent left superior vena cava coursed

vertically down anterior to arch of aorta and left

pulmonary trunk (Fig.1). When traced, it opened

into an enlarged coronary sinus that further drained

into the right atrium (Fig.2). There was no

communication between the two vena cavae. The

persistent left superior vena cava had the same

length and caliber as compared to the right superior

vena cava (Fig.1, Fig.2). A left azygos vein

replaced the accessory azygos and the hemiazygos

veins. It ran upward along the left side of vertebral

column and arched over the root of the left lung to

drain into PLSVC (Fig.3).

The azygos and the left azygos veins did not

communicate with each other. Azygos system was

made up of bilaterally symmetrical veins. Right

superior vena cava was present as a continuation of

right brachiocephalic vein which in turn formed by

the union of right internal jugular vein and right sub

clavian vein. Right superior vena cava opened into

right atrium and received the drainage of azygos

vein (Fig.2). No other associated anomaly of heart

was observed.

cardinal and leftcommon cardinal veins. PLSVC

may open into left atrium of the heart, coronary 2sinus, right superior vena cava is innominate vein.

Persistent left superior vena cava is a rare venous

malformation. There is limited number of

cadaveric study on this anomaly.

The reason is that the double superior vena cava

often associated with cardiovascular anomalies,

allowing only the limited number of adult patients

to survive. However, the developments of

procedures for cardiovascular catheterization and

clinical imaging examinations have increased the

number of anomaly is being reported. It is

estimated to occur in 0.3- 0.5% of the general

population and 3-10% of patients with other forms 3,4

of congenital heart disease.

Double superior vena cava is usually asymptomatic

unless other cardiac anomalies exist. It is frequently

associated with cardiac abnormalities like

ventricular septal defect, atrial septal defect or

endocardial cushion defect that have significant 5mortality and morbidity. PLSVC may also

interfere and cause problems during various

invasive procedures such as pacemaker

implantation, central venous catheterisation,

retrograde delivery of cardioplegia and retrograde 6,7,8left ventricular pacing.

The aim of the present study is to find the frequency

of double superior vena cava, its embryological

basis and to correlate its clinical significance. The

present study also compared the frequency of

double superior vena cava reported in other similar

studies.

MATERIALS AND METHODS:

This is a descriptive study which includes the

cadavers allotted for first year MBBS students in

Department of Anatomy at VelammalMedical

Sabita Singh, et.al : Double Superior vena cava with paired Azygos vein


109

Fig.1 : Heart in situ showing double superior vena cavae without any communication between them.

RSVC- right superior vena cava, PLSVC- persistent left superior vena cava, PT- pulmonary trunk.

Fig.2. : Posterior view of resected heart showing double azygos vein with double superior vena cavae.

Rightazygos draining into right superior vena cava and left azygos vein draining into persistent left

superior vena cava. Persistent left superior vena opening into enlarged coronary sinus. RSVC- right

superior vena cava, PLSVC- persistent left superior vena cava, RAV- right azygos vein, LAV-left azygos

vein, CS-coronary sinus.

Fig.3 : Dissected thoracic cavity showing left azygos vein draining into persistent left superior vena cava.

LAV- left azygos vein, PLSVC- persistent left superior vena cava

Fig.4 : Posterior view of resected heart showing double superior vena cava with double azygos vein. Left

brachiocephalic vein present which unite with right brahiocephalic vein to form right superior vena cava.

Persistent left superior vena cava and left azygos vein are of reduced dimension as compared to right side.

Coronary sinus are dilated into which persistent left superior vena cava drained. RSVC- right superior

vena cava, PLSVC- persistent left superior vena cava, RBCV- right brachiocehalic vein, LBCV- left

brachiocephalic vein, CS-coronary sinus



110

present study. They classified the cases according

to the presence / absence of pairing of

azygousveins, as well as the presence / absence of

anastomotic branch, into the following 4 types:

I) The pattern with an anastomotic branch

between the right and left superior vena cava, II) the pattern without any anastomotic branch, III) the pattern showing the presence of the left

superior vena cava alone and degeneration and

disappearance of the right superior vena cava,

andIV) the pattern of the double superior vena cava

12with paired azygos veins . In the present study

cases were of type IV.

During the fifth week of intrauterine life, in the

human fetus, three pairs of major veins can be

distinguished: the vitelline veins, carrying blood

from the yolk sac to the sinus venosus; the

umbilical veins, originating in the chorionic villi

and carrying oxygenated blood to the embryo; and

the cardinal veins, draining the body of the embryo

proper. The cardinal veins form a pair of

symmetrical venous system. They consist of the

anterior cardinal veins, which drain the cephalic

part of the embryo, and the posterior cardinal veins,

draining the remaining part of the body of the

embryo.

The anterior and posterior cardinal veins join to

form common cardinal veins and enter the right and

left horns of the sinus venosus. Formation of the

vena cava system is characterized by the

appearance of anastomosis between the left and

right sides in such a manner that the blood from the

left side is directed to the right side. The left anterior

cardinal vein above and the anastomosis between

the anterior cardinal veins develops into the left

brachiocephalic vein. Most of the blood from the

left side of the head and the left upper extremity is

thus directed to the right. The superior vena cava is

Case 2- Adult female cadaver aged 55 years :

PLSVC was formed by the union of left internal

jugular vein and left subclavian vein which in turn

opened into coronary sinus. PLSVC was smaller in

size than right superior vena cava. Right superior

vena cava was formed by the joining of right and

left brachiocephalic vein. Azygos system was made

up of bilaterally symmetrical veins like that of

previous case. But left side azygos vein was very

small (Fig.4). Patent foramen ovale was present in

the heart.

DISCUSSION :

There are many anatomical variations of superior

vena cava found due to its complex development. A

double superior vena cava with a persistent left

superior vena cava is an uncommon abnormality

but is the most common thoracic venous anomaly 9

in the setting of SVC . Anomalies of superior vena

cava have been classified by many authors.

McCotters classified double superior vena cava

into following five types based upon anastomosis

between right and left superior vena cava:

1) Double superior vena cava without anastomosis, 2) Double superior vena cava with small

anastomosis,3) Double superior vena cava with normal

anastomosis, 4) Left superior vena cava without right, and

105) Persistent left superior vena cava unclassified.

In the present study, case1 belonged to type 1 and

case 2 was of type 5. Thomas et al classified the

PLSVC into two types one connecting to right

atrium via the coronary sinus (90%) and the other 11

connecting to left atrium (10%) . Rare cases of

double superior vena cava with pairedazygos vein

had been reported. Nandy and Blair had reported

double superior vena cavae with bilaterally

symmetrical azygos veins, which was similar to the



111

M.Uemura. 2,17 But AP. Gesase et al have shown

highfrequency10 - 11% of the double superior vena

cava but that was observed in congenital heart 18

disease patients. The present study showed 2.22%

of frequency of double superior vena cava.

PLSVC is asymptomatic and compatible with life

unless the PLSVC opens into the left atrium or is

accompanied by other congenital heart defects like

atrial septal defect, ventricular septal defect and 19tetralogy of Fallot. Other congenital anomalies in

the heart and an associated shunt between the right

and the left cardiac system occurring should be

considered from the presence of the persistent left 14superior vena cava. PLSVC may drain into left

atrium in 7.5% cases which results in small right to

left shunt. This hasa minor haemo dynamic effect,

mainly a variable degree of systemic cyanosis and 20,21

may lead to clinical symptoms. PLSVC may

also give rise to rhythm disturbances such assinus

node dysfunction and atrioventricular block. The

serhythm problems may be related to the stretching

of the conduction tissue caused by the enlargement 7,8

of the coronary sinus. LSVC has been associated

with an increased risk of arrhythmias, most 22

commonly atrial fibrillation.

The knowledge of existence of PLSVC during CT

scan evaluation of the mediastinum is important

because LSVC can be mistaken for alymph node 23and result in false staging of lung cancer. Invasive

procedures like cardiac pacemaker implantation,

resynchronization therapy, radio frequency

catheter ablation, internal jugular or subclavian

vein catheter insertion require detailed echo cardio

graphic studies of this rare congenital anomaly to 6,7,20

avoid further complication. Awareness of

PLSVC is necessary for intensive care clinicians

not to place catheters outside the venous circulation

& to avoid complications like perforation, shock, 20

cardiac arrest, cardiac tamponade and thrombosis.

thus formed by the right common cardinal vein and

the proximal portion of the right anterior cardinal

vein. On the other hand, the left common cardinal

vein and the distal part of the left horn become

atretic and forms the ligament of Marshall or

ligament of the left superior vena cava. The caudal

part of anterior cardinal vein distal to the

anastomosis obliterates. The failure of this normal

regression i.e, persistence of left anterior cardinal

vein and left common cardinal vein results in

PLSVC.

During fifth to seventh week, a number of

additional veins are formed: a) subcardinal vein,

which mainly drain the kidneys b) sacrocardinal

vein, which drain the lower extremity and

c)supracardinal vein, which drain the body wall by

way of the intercostal veins, taking over the

functions of the posterior cardinal vein after its

major obliteration. Azygos venous system

develops from a pair of the right and left

supracardinal veins. Both supracardinal veins

communicate with the posterior cardinal veins to

form the primordium of a pair of right and left

azygos veins. Subsequently, right supracardinal

together with a portion of posterior cardinal forms

the azygos vein. On the other hand, left

supracardinal vein forms hemiazygos vein which

drains into azygos vein.13 The left azygos vein

appears to be developed from the persistent

proximal portion of the left posterior cardinal vein 12

and the left supracardinal vein.

There are differences in frequency of double

superior vena cava showed by various studies. A

persistent left superior vena cava is the most

common anomaly of abnormal veins flowing into

the heart, with a frequency of 0.3 - 0.5% in healthy

individuals, and 2 - 4% in patients with congenital 14,15,16heart diseases. The frequency of double

superior vena cava reported by various authors are

as follows- 0.16% by Bergman RA, and 0.3% by



112

these diagnostic techniques, other associated

congenital anomalies should be investigated so as

to comprehend the risks related to catheterization

and selection of a safe route should be considered.

CONCLUSION :

Although the double superior vena cava is a rare

congenital anomaly, prior knowledge of it and the

associated anomalies should be considered

seriously by surgeons, sonographers and

interventional radiologists. This can prevent

possible complications in routine clinical practice

and during cardiopulmonary bypass and minimize

the diagnostic errors. As the literature available on

this congenital anomaly is sparse, the present study

can add to the existing knowledge of this congenital

anomaly and stresses on its significant clinical

implications, especially during central venous

catheter placement or during surgical procedures in

the chest.

CONFLICTS OF INTEREST :

The authors have none to declare.

ACKNOWLEDGEMENT :

The authors would like to acknowledge the help

and support rendered by the faculties of

Department of Anatomy and dissection hall staff of

Velammal Medical College, Madurai.

REFERENCES :

1. Fabian FM, Gesase AP, Ngassapa DN: Double superior vena cava presenting with anomalous jugular and azygous venous systems. Indian Heart J. 2008;60:352–358.

2. Bergman.A - Compendium of Human Anatomic Variation; Lippincott Williams and Wilkins Baltimore, Urban &Schwarzenberg: 1988; p88.

Central venous cannulation may result in unusual

catheter positions and inadvertent coronary

sinuscannulation may result in cardiac 22,24

perforation. Cannulation of the heart having

PLSVC for cardiopulmonary bypass may result in 25

in effective retrograde cardioplegia. Therefore

during cardiac surgery, the presence of PLSVC

with adequate development of left brachiocephalic

vein is a relative contraindication to the

administration of retrograde cardioplegia. It may

be possible to clamp the PLSVC to avoid the

cardioplegia solution from perfusing retrograde up

the PLSVC and its branches. However, there is a

possibility that there may be some steal of 21cardioplegia solution through an accessory vein.

If the right superior vena cava is absent, all venous

return from the upper body will drain through the

PLSVC.

Hence, this may affect the use of the retrograde 4

cardioplegia. In such a case, occlusion or ligation

of the PLSVC would be fatal as this may result in

cerebral congestion. During heart transplantation

in a patient with PLSVC, the coronary sinus must

be dissected carefully to permit re-anastomosis of 4,8

PLSVC to right atrium. The dilated coronary

venous sinus associated with PLSVC obscure

contrast radiographic findings of the interatrial

septum and the space between the ventricles on 14

cardiac angiography.

Transthoracic echo cardio grapy including agitated

saline infusion to both antecubital vein - CT or MRI

are important non-invasive diagnostic tools for

accurate diagnosis of this rare congenital venous 4malformation. However, the gold standard for the

definitive diagnosis of double SVC is usually 26

discovered with invasive angiography. The left

SVC opening to the right atrium through the

coronary sinus can be clearly shown by MPR and 27

3D VR obtained through MDCT. When the

persistent left superior vena cava is ascertained by



113

13. SadlerTW.Langman'sMedical Embryology. 11th ed. WoltersKluwwer: LippincotWilliams and Wilkins. 2010; 193-195.

14. B. Singh, L. Ramsaroop, J. Maharaj, A.Reddi. Case of double superior vena cava.ClinAnat 2005;18:366 –369.

15. J. Peltier, C. Destrieux, J. Desme, etal.The persistent left superior vena cava: anatomical study, pathogenesisand clinical considerations. SurgRadiol Anat. 2006; 28:206-210.

16. H. Chen, S. Shoumura and S. Emura.Bilateral thoracic ducts with coexistent persistent left superior vena cava.Clin Anat. 2006;19:350 –353.

17. Uemura M, Takemura A, EharaD, et al. Left superior vena cava with leftazygos vein. Okajima Fol. Anat.2009; 86(2):55– 60.

18. Ainory P. Gesase, Flora M. Fabian, David N. Ngassapa. Doublesuperior vena cava presenting with anomalous jugular and azygousvenoussystem.Indin Heart.2008; 60:352–358.

19. Cormier Mg, YedlickaJw, Gray Rj. Congenital anomalies of the superior vena cava: A CT study. Seminars inRoentgenology.1989; 24: 77-83.

20. Erdogan M, Karakas P, Uygur F. Persistent left superior vena cava: the anatomical and surgical importance. West Indian Med J. 2007;56:72- 76.

21. Paval J, Nayak S. A persistent left superior vena cava.Singapore Med J. 2007;48:90-93.

22. Ratliff HL, Yousufuddin M, Lieving WR, etal.Persistent left superior vena cava: case reports and clinical implications. Int J Cardiol. 2006;113:242–6.

3. Akira Limura, TakeshiOguchi, Masakazu Shibata. Double superior vena cava and anomaly of cardiovascular system with a review of the literature.OkajimasFolia Anat. Jpn. 2011;88(1):37–42.

4. Yurtdas M, SahinM. Double superior vena cava (persistent left superior vena cava draining into the coronary sinus) - case report. Eastern Journal of Medicine. 2013;18:23-25.

5. Mori. C, Hashimoto. H, Hoshino K. Two cases of double superior vena cava.Jpn Heart J.1990;31(6):881-888.

6. Biffi M, Boriani G, Frabetti L. Left superior venacava persistence in patients undergoing p a c e m a k e r o r cardioverterdefibrillatorimplantation: a 10-year experience. Chest. 2001;120:139-144.

7. Chandra A, Reul GJ Jr. Persistent left superior vena cava-Discovered during placement of central venous catheter. Tex Heart Inst J. 1998;25:90.

8. Goyal SK, Punnam SR, Verma G. Persistent left superior vena cava: a case report and r e v i e w o f l i t e r a t u r e . CardiovascUltrasound.2008; 6: 50.

9. Chen M, Ma Ji, XuG.Double superior vena cava with a persistent left superior vena cava. The Japanese Society of Intern Med. 2008;47:679 - 80.

10. McCotter R.E. Three case of persistence of left superior vena cava. Ana Rec.1915;10:371-383.

11. Thomas. C. Gerber, Ronald SKuzo. Persistent left superior vena cava demonstrated with multislice spiral computed tomography. Circulation. 2002;105:109

12. Nandy K, Blair Cb Jr. Double superior vena cavawith completely paired azygos veins. AnatRec. 1965;151:1-9.



114


23. Tzilas V, Bastas A, Koti A. Persistent left superior vena cava mistaken for nodal m e t a s t a s i s : a c a s e r e p o r t . J M e d CaseReports.2010; 4:174.

24. Azocar RJ, Narang P, Talmor D.Persistent left superior vena cava identified after cannulation of the right subclavian vein. Anesth Analg. 2002;95:305–7.

25. Hanson E, Hannan R, Baum V. Pulmonary artery catheter in the coronary sinus: implication of persistent left superior vena cava for retrograde cardioplegia. J CardiothoracVascAnesth 1998;12:448–449.

26. Chad J.Cooper, Anwar SolimanGerges, Emmanuel Anekwe, German T. Hernandez. American journal of Case Reports. 2013;14:395-397.

27. Onbas O, Kantarci M, KoplayM. Congenital anomalies of the aorta and vena cava: 16-detectorrow CT imaging findings. DiagnInterv Radiol. 2008; 13:163-171


Received on 23/01/2019 Revised on 25/02/2019 Accepted on 07/03/2019

sabita singh - njbmsnjbms.in/uploads/19/6330_pdf.pdf · 107 original article sabita singh1,...

Documents