1. Seminar topic: “Venous drainage of thoracic wall”
LimKuan Yan,
Taylor’s University MBBS, Batch 5.

2. Veins that we going to discuss today
Internal thoracic vein
Intercostal vein (Ant & Post.)
Azygos Vein
Hemiazygos vein
Accessory vein

3. Internal Thoracic Vein the (Internal Mammary Vein)
Is a vessel that drains the chest wall and breasts.
Bilaterally, it arises from the superior epigastric vein,
Accompanies the internal thoracic artery along its course and terminates in the brachiocephalic vein.

4. Intercostal Vein

5. Anterior intercostal Vein
In each of the upper nine spaces
Two anterior intercostal veins
They accompany the corresponding arteries
Termination of Ant. Intercostal.V
In upper 3 spaces, the veins end in the internal thoracic vein
In upper 4-6 spaces, the veins end in vena comitantes accompanying internal thoracic artery.
In lower 7-9 spaces, the viens end in vena comitantes accompanying muculophrenic artery

6. Musculophrenic artery & Internal Thoracic artery

7. Posterior intercostal Vein
In each of upper nine spaces
One posterior intercostal vein
One collateral vein
Each vein accompany the corresponding artery and lies superiorly to the artery
V.A.N
Collateral branch of the posterior intercostal vein
Posterior intercostal Vein

8. Termination of Post. Intercostal Vein
Postrior intersotal Veins (P.I.V)
P.I.V on the right drain into
P.I.V on the left drain into
1st
Right brachiocephalic.V
Left Brachiocephalic.V
2-4th
(Right side = Joined together and form right sup. Intercostal vein)
(Left side = Joined together and form left sup. intercostal vein)
Azygous.V
5-8th
Accesory hemiazygos .V
9-11th + subcostal V (12th)
Hemiazygos.V
Left sup. Int. costal vein
Right sup. Int. costal vein
Accesory hemizygous V.
Hemizygous V.
Right subcostal vein
Left subcostal vein

9. Azygos (Unpaired) Vein
General info
Azygos vein drain the thoracic wall and the upper lumbar region.
It forms and important channel connecting the sup. & inf. Vanae cavae
The vein occupies the upper part of post. Abdominal wall and post. Mediastinum
It connects portal venous system to caval venous system.
Formation
The azygos.V is formed by union of
Lumbar azygos.V (Abdominal part of azygos.V)
Lies to the right of lumbar vetebrae
It’s lower end communicates with IVC
Ascending lumbar.V (Formed by verticle anastomoses that connect the lumbar vein)
Right subcostal.V (Accompany by right subcostal artery)

10. Azygos (Unpaired) Vein
Course
Ascends up
Pass through the aortic opening of the diaphragm
Enter throax
Continue ascend up to T4
Form arches forward over the root of the right lung
Joined the post aspect of sup.vena cava (just before piercing into the pericardium)
THE END
Relation
Ant = Oesophagus
Post = Lower 8 throcic vetebraes ( T5-T12)
= Right post. Intercostal arteries
Right = Right lung
= Pleura
Left = (lower part) => Thoracic duct + aorta
= (upper part) =>Oesophagus + trachea +
vagus nerve

11. Hemiazygos (Inferior hemiazygous) Vein
General info
It is mirror immage of lower part of the azgos vein.
Formation
Hemiazyos vein is formed by union of
Left lumbar azygos.V
Left ascending lumbar.V
Left subcostal.V

12. Hemiazygos (Inferior hemiazygous) Vein
Course
Ascend upward
Pierce the left crura of the diaphragm
Go upward along with the left side of the vetebrae
Overlapped by aorta
At T9 go right side of the vetebrae
Passes behind oesophagus
Joins the azygos.V
THE END
Tributaries
9th to 11th left post. Intercostal.V
Oesophagus.V

13. Accessory (Superior hemiazygos) Vein
General info
It is the mirror image of upper part of azygos vein.
Course
Begin with medial end of 4th or 5th intercostal space
Descends downward on the left side of the vertebral column
At the level of T8,it turns to the right side of vetebrae
Passes behind the aorta & thoracic duct
Join with azygos.V
THE END
Tributaries
5th to 8th left post. Intercostal.V

14. References

15. Thank you !!!