hemiazygos vein


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Related to hemiazygos vein: accessory hemiazygos vein, thoracic duct

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 ?
Malposition of a dialysis catheter in the accessory hemiazygos vein. Anesth Analg.
The diameters of the azygos vein (AV), hemiazygos vein (HV) and accessory hemiazygos vein (AHV) at various levels: all measurements in mm.
Multiple variations in the azygos venous system: a preaortic interazygos vein and the absence of hemiazygos vein. Surg.
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
The lumbar vein then ascended upwards in the thorax and joined with the left subcostal vein to continue further up as the accessory hemiazygos vein (figure 3).
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.
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.