hemiazygos vein

(redirected from Hemiazygos)

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 ?
Key words: Left superior intercostal vein, accessory hemiazygos vein, persistant left superior vena cava, multidetector computed tomography angiography
16-MDCT depiction of accessory hemiazygos vein draining in to the left brachiocephalic vein.
The portion of the right supracardinal vein cephalad to the kidneys becomes the azygos vein; similarly, that portion on the left forms the hemiazygos system.
One-third of bronchial venous drainage flows via the azygos, hemiazygos and intercostal veins to the right atrium.
An enlarged azygos system (azygos and hemiazygos diameters together equal greater than 10 mm) (2) associated with a posterobasal chest lesion may suggest the diagnosis.
This patient and at least 2 others have had intrahepatic interruption of the inferior vena cava with azygos continuation (6), and persistence of the left hemiazygos vein has been described (3).
9) described a case of absent hepatic portion of the IVC with hemiazygos drainage direct into the left atrium, with questionable, persistent left SVC.
Left-sided or transposed inferior vena cava ascending as hemiazygos vein and draining into the coronary sinus via persistent left superior vena cava: case report.
In the literature, several case reports about persistence of the left IVC with its azygos or hemiazygos continuation have been reported (3-8).
We considered that persistent left IVC, which continues as vena hemiazygos drained into right atrium via persistent left SVC connecting to coronary sinus (Fig.
Examples of mediastinal vascular anomalies include left aortic arch, cervical aortic arch, right aortic arch with aberrant left subclavian artery, right arch with mirror-image branching, double aortic arch, aortic coarctation, persistent left superior vena cava, a double superior vena cava, retroaortic innominate vein, circumaortic innominate veins, interruption of the inferior vena cava with azygos and hemiazygos continuation, pulmonary artery sling, congenital absence of the left pulmonary artery, pulmonary valvular stenosis, patent ductus arteriosus, pulmonary varix, and partial anomalous pulmonary venous return.