Question: What is (are) Pulmonary vein stenosis ?
Answer: Pulmonary vein stenosis is a very rare and serious condition in which there is a blockage in the blood vessels that bring oxygen-rich blood from the lungs back to the heart. This condition can be isolated to one vein, but often affects multiple veins. Stenosis occurs when there is an abnormal thickening and narrowing of the walls of the veins. Pulmonary vein stenosis is a progressive condition and may lead to total obstruction to a blood vessel. Most commonly, all of the pulmonary veins of one lung are affected, causing pulmonary hypertension and pulmonary arterial hypertension. Surgery and catheterization to widen the narrow veins is usually a short-term solution since the obstruction typically recurs.
Source: GARD