What is azygos continuation of inferior vena cava?
Abstract. Interruption of the inferior vena cava (IVC) with azygos continuation is a rare congenital anomaly, in which the IVC is interrupted below the hepatic vein and venous return beyond this point is restored by the dilated azygos and hemiazygos veins draining into the superior vena cava.
Where does Hemiazygos vein drain?
It arches anteriorly just above the hilum of the right lung and drains into the superior vena cava. The hemiazygos vein arises from the left ascending lumbar vein. It drains the lower left posterior intercostal veins and ascends on the vertebral bodies posterolateral to the descending aorta.
What is inferior vena cava?
The inferior vena cava is a large, valveless, venous trunk that receives blood from the legs, the back, and the walls and contents of the abdomen and pelvis.
What does the azygos vein connected to?
The azygos vein is a vein running up the right side of the thoracic vertebral column draining itself towards the superior vena cava. It connects the systems of superior vena cava and inferior vena cava and can provide an alternative path for blood to the right atrium when either of the venae cavae is blocked.
Does hemiazygos vein drain into azygos?
The hemiazygos vein runs in the posterior mediastinum and drains into the azygos vein at the level of the eighth thoracic vertebra.
What does azygos vein drain?
It is responsible for draining the thoracic wall and upper lumbar region via the lumbar veins and posterior intercostal veins 1. It also provides important collateral circulation between the superior and inferior venae cavae should they become obstructed 2.
What causes azygos fissure?
A convex shaped fissure is created by the course of the vein bearing towards the medial side of the right lung to join with the superior vena cava. Its formation is the result of an unusual embryogenic migration of the posterior cardinal vein, which is a precursor of the vena azygos.
What is the prevalence of azygos continuation of the IVC?
Azygos continuation of the IVC has a prevalence ~1.5% (range 0.2-3%) 1. In most cases, it is found incidentally in asymptomatic patients. An association with congenital heart disease and asplenia or polysplenia syndromes have been reported.
Azygos continuation of the inferior vena cava. Azygos continuation of the inferior vena cava (also known as the absence of the hepatic segment of the IVC with azygos continuation) is an uncommon vascular anomaly and is a cause of a dilated azygos vein.
Can an interrupted infrahepatic IVC with azygos continuation with sick sinus syndrome?
The case of 47 year old woman with an interrupted infrahepatic IVC with azygos continuation accompanied by sick sinus syndrome and a structurally normal heart is reported. Negotiating a temporary pacing lead from the IVC to the right atrium was difficult.
How does the renal segment drain into the azygos vein?
Instead, there is an interruption of the infrahepatic/suprarenal portion of the IVC. This represents a failure of fusion of the vitelline and subcardinal embryological portions of the IVC. The renal segment of the IVC, therefore, drains via the azygos vein (or in rare cases, the hemiazygos vein if there is a left-sided IVC ).