Trunk vessels (aorta, vena cava, abdominal branches)
Accessory hemiazygos vein
Vena hemiazygos accessoria
- Origin
- Descends along the left side of the thoracic vertebrae collecting the 4th to 8th left posterior intercostal veins
- Insertion
- Crosses the T7-T8 vertebral level posterior to the aorta and esophagus to drain into the azygos vein
- Function
- Drains the mid-thoracic left chest wall and left bronchial veins
- Innervation
- Thoracic sympathetic fibers
- Movement & chain
- Venous return into the azygos system
- Palpation
- Not palpated directly
- Clinical
- Collateral venous route in left upper mediastinal congestion or SVC syndrome.
- Segmental innervation
- T4-T8 spinal levels
- In clinical practice
- Chest CT assessment in suspected thoracic venous abnormalities
- Region in the model
- Trunk vessels (aorta, vena cava, abdominal branches)