What are PAVMs?
Pulmonary arteriovenous malformations (PAVMs) are developmental anomalies involving the arteries going to the lungs and the veins returning from the lungs. The anomaly is a direct communication between the artery and vein, instead of the normal capillary bed. As the blood flows through this communication with no resistance, these communications can expand and dilate (turn into aneurysms). In addition, when these communications are present, anything that is in the venous system can freely cross over to the arterial system. The lungs normal act as a filter to prevent this from happening. When this filter is absent, blood clots, bacteria, even air can cross this communication and can result in a stroke, brain abscess, or other issues.