This document discusses anomalies of the systemic venous return. Some anomalies have little clinical significance while others can cause cyanosis. Preoperative knowledge of venous anomalies is important for surgery as they impact techniques like venous cannulation. Common anomalies include persistent left superior vena cava and interrupted inferior vena cava with azygous continuation. These anomalies are often associated with other congenital heart defects.

1. Anomalies of the systemic
venous return
Dr. Anup kumar Sarkar
MS (CVTS) final part student
NHFH&RI

2.  A wide variety of abnormalities appears in the systemic venous
system; some of these have little physiologic importance and
others produce cyanosis.
 Some of these anomalies produce difficulties during surgery and
preoperative knowledge is important.
 Anomalies of systemic venous return are frequently associated
with other congenital cardiac defects and with atrial isomerism.

3. Embryology
• In the 5th week of development, three
pairs of major veins can be
distinguished
The cardinal veins: draining blood of
embryo proper.
The vitelline veins (omphalomesenteric
vein): carrying blood from yolk sac to
sinus venosus
The umbilical vein: originating in
chronic villi, carrying oxygenated blood
to embryo.

4. The cardinal system forms the caval system.
The vitelline system develops into the portal system.
The umbilical system disappears after birth.

5. During the fifth to the seventh
weeks, a number of additional veins
are formed:
 The subcardinal veins- mainly
drain the kidneys
The sacrocardinal veins- drain the
lower extremities.
The supracardinal veins- drain the
body wall by way of the intercostal
veins.

6. Anomalies of the superior vena cava
Persistent left SVC draining into RA
• Result from failure of the left
anterior and left common cardinal
vein to involute.
• Does not produce any functional
significance

7. Diagnosis
Chest radiography films may
show the shadow of the left SVC
along the upper left border of
mediastinum

8. Diagnosis
2D echocardiography-100%
specificity and 96% sensitivity
Enlarged coronary sinus is often
the first clue to diagnosis of
PLSVC

9. Surgical importance
-Techniques of venous cannulation
-Route of administration of cardioplegia
-Intra-cardiac repair of associated anomalies in specific
surgical situations

10. Persistent LSVC draining into left atrium
Rarely PLSVC drains into the LA,
resulting in systemic arterial
desaturation.
Associated cardiac anomalies are almost
invariably present.
Echo study with colour flow mapping
usually provide adequate diagnosis.

11. Treatment
• Surgical correction is necessary.
• If there is an adequate-size bridging vein that connects two SVCs,
simple ligation of the LSVC is performed.
• If the right SVC is absent or a bridging vein is inadequate, the LSVC
is transposed to the RA.

12. Anomalies of Inferior Vena Cava
Significant anomalies are:
Interrupted IVC with Azygous continuation
IVC connecting to the left atrium
Bilateral Inferior Vena Cava

13. Interrupted IVC with azygous continuation
The IVC is made up of four segments during
the embryonic period, and failure of the
formation of hepatic segment results in an
interrupted IVC
Frequently associated with complex
congenital heart disease.
Hepatic veins continue to drain into right
atrium as a single trunk or as separate vessels.

14. Interrupted IVC with azygous continuation
This anomaly does not result in clinical manifestations.
Can be readily diagnosed by echocardiography.
No specific treatment is indicated.
Surgical importance during venous cannulation.

15. Coronary sinus anomalies
Coronary sinus defect and unroofed CS
Coronary sinus orifice atresia
Coronary sinus aneurysm or diverticulum

16. Coronary sinus defect and unroofed CS
Unroofed coronary sinus almost
always is associated with PLSVC
A CS defect without an
associated LSVC, the physiology
is the same as in ASD.
Diagnosis by Echocardiography
Surgery is performed for
associated malformations

17. Take Home Message
A wide variety of abnormalities appears in the systemic venous
system and frequently associated with others cardiac anomalies.
Persistent LSVC is most common anomaly of SVC and PLSVC can drain
either in RA or LA.
Interrupted IVC with azygous continuation is most common anomaly
of IVC.
Systemic venous anomalies have surgical importance during venous
cannulation, intra-cardiac repair and cardioplegia delivery; hence
preoperative diagnosis is important.