hemiazygos vein

(redirected from Hemiazygos veins)

hem·i·az·y·gos vein

[TA]
formed by the merger of the left ascending lumbar vein with the left subcostal vein or a communication from the inferior vena cava, it pierces the left crus of the diaphragm, ascends along the left side of the bodies of the lower thoracic vertebrae, opposite the eighth vertebra, crosses the midline posterior to the aorta, thoracic duct, and esophagus, and empties into the azygos vein, sometimes in common with the accessory hemiazygos vein.

hem·i·a·zy·gos vein

(hem'ē-ā-zī'gŏs vān) [TA]
Formed by the merger of the left ascending lumbar vein with the left subcostal vein or a communication from the inferior vena cava, it pierces the left crus of the diaphragm, ascends along the left side of the bodies of the lower thoracic vertebrae, opposite the eighth vertebra, crosses the midline behind the aorta, thoracic duct, and esophagus, and empties into the azygos vein, sometimes in common with the accessory hemiazygos vein.

hemiazygos vein

A vein running along the back wall of the lower thorax on the left side of the thoracic aorta. At the level of the eighth thoracic vertebra, the hemiazygos vein bends to the right, runs behind the aorta, and empties into the azygos vein. Tributaries to the hemiazygos vein include the left bronchial, left lower intercostal, left subcostal, and left ascending lumbar veins; often, there is a caudal anastomosis with the left renal vein. The patterns and interconnections of the azygos, hemiazygos, and accessory azygos veins are variable.
See also: vein
References in periodicals archive ?
Before replacing a new permanent catheter, a venography for upper extremities and superior vena cava was performed by interventional radiology and no flow of contrast agent was observed in superior vena cava vein, suggesting an obstruction in vena cava superior vein and right and left juguler vein's blood flows were through azygos and hemiazygos veins respectively.
These veins communicate with each other as well as the paired azygos lines and develop into the reaortic-aortic connections of the left lumbar and hemiazygos veins (Stranding).
The interazygos veins can be formed by independent left posterior intercostal veins uniting to form a common trunk, the hemiazygos, accessory hemiazygos veins or the commonly found hemiazygos - accessory hemiazygos anastomosis (Celik et al, 1996; Gilkeson et al, 1997; Ozbek et al, 1999; Ozdemir et al, 2002).
The preaortic interazygos vein was a direct continuation of the hemiazygos vein which drained the 9th to 11th left posterior intercostal veins.
The exam revealed multiple collateral venous pathways, such as the azygos and hemiazygos veins, internal and lateral thoracic veins, and vertebral venous plexus.
It contains the thoracic part of the descending aorta, the azygos and the two hemiazygos veins, the vagus and splanchnic nerves, the esophagus, the thoracic duct, and some lymph glands.
In this instance, the blood related to the lower segment of the body reaches the heart through hypoplastic IVC, the azygos and hemiazygos veins which appear dilated, and also through various collaterals developed as a compensation.
In the thoracic region, the supracardinal veins give rise to the azygos and hemiazygos veins. Progressive changes in the abdomen lead to replacement of the postcardinal veins by the subcardinal and supracardinal veins.
Communications of the hemoazygos, accessory hemiazygos veins into the azygos vein are identified and exposed by reflecting the oesophagus and aorta upwards.
The azygos system of veins is considered to be, the azygos vein, along with its left-sided counterparts, the hemiazygos vein and the accessory hemiazygos vein.
The left complement of this venous channel which drain the upper abdominal parietals and the lower thoracic wall in named as accessory hemoazygos vein or superior hemiazygos vein. Both of them drain into the azygos vein
More rarely cases of LSIVC, possible routes for the return of blood to RA are via the azygos vein to SVC, via the left brachiocephalic vein to the right SVC, or via the hemiazygos vein to PLSVC(3).