Azygos vein to pulmonary vein fistula is a pathway for cerebral embolism
Related Experiment Video
Updated: Jun 9, 2026

Comprehensive Endovascular and Open Surgical Management of Cerebral Arteriovenous Malformations
Published on: October 20, 2017
Yining Huang1, Wei Sun, Fan Li
1Department of Neurology, Peking University First Hospital, Beijing, China. yiningh@yahoo.com
Abstract:
A 43-year-old man was admitted for right upper and lower limb weakness and aphasia. He had suffered dizziness and transient blindness 6 months ago and had also been found lying in the bathroom on another occasion. Multiple cerebral infarctions were confirmed by brain CT scan and MRI. Diffuse nodes in the mediastinum and postperitoneum had been found in pulmonary CT scans and MRI scans since 1999. Pulmonary CT scan revealed multiple bilateral pneumatoceles in the lungs. Contrast CT scan showed an enlarged azygos vein on the right side of the spinal column and an enlarged azygos arch. CT scan-guided biopsy revealed a few fibers, fat, and vascular tissues in the mass. Transcranial Doppler bubble test showed gas microembolic signals in both middle cerebral arteries. Pulmonary digital subtraction angiogram confirmed an enlarged azygos vein. A fistula was found between the pulmonary and azygos veins with turbulent flow from pulmonary to azygos at rest. Cavography revealed that the pulmonary vein appeared simultaneously with the superior cava vein during Valsalva maneuver. In summary, the pathway of cerebral embolism was based on three pathologic mechanisms: (1) increased inferior vena cava pressure, (2) enlarged right azygos aneurysm, and (3) the presence of a fistula between the azygos and pulmonary veins.
Related Concept Videos
Pulmonary Embolism I: Introduction
Pulmonary Embolism I: Introduction
Venous Thrombosis I: Introduction
Cerebral Edema ll: Pathophysiology
Veins of Thorax
The azygos vein, positioned just right of the midline and anterior to the vertebral column, begins at the junction of the right ascending lumbar and subcostal veins, terminating in the superior vena cava. This vein drains blood from the right side of the thoracic wall, thoracic viscera, and posterior abdominal wall.
The...
Overview of Systemic Veins
The coronary sinus, the heart's principal vein, resides in the coronary sulcus on the heart's posterior aspect. This broad venous channel receives nearly all venous blood from the myocardium, the heart muscle. It is fed by three primary veins: the great cardiac vein, the middle...