Azygos and hemiazygos continuation: An occasional finding in emergency department

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. A case of the interruption of the IVC with azygos/emyazygos continuation for the absence of the hepatic segment of IVC, left renal vein duplication, and polysplenia is reported. The embryologic, clinical, and radiological significance are discussed.

The diagnosis is suggested by X-ray, but contrast-enhanced multidetector computed tomography is the method of choice to diagnose this venous anomaly and reveals the aberrant vascular structures.

Awareness of different congenital anomalies of IVC is important to surgeons and cardiologists and is necessary for radiologists to avoid diagnostic pitfalls and for preoperative planning: they should be remembered because they can influence several surgical interventions and endovascular procedures. Accidental ligation of the azygos vein is fatal and cardiac catheterization using the lower extremity vein is troublesome in patients with this condition.

Giant azygos vein varix

Primary anomalies of the azygos vein generally result from intrathoracic tumor compression or inferior vena caval interruption with azygos vein continuation. Vascular malformations, although uncommon, can frequently mimic solid tumors and present as middle or posterior mediastinal masses. We present the case of an isolated giant azygos vein varix in an asymptomatic patient. Preoperative computed tomography and magnetic resonance imaging were not diagnostic in evaluating this patient's anatomy.