Endobronchial changes in chronic pulmonary venous hypertension.

The bronchial venous system closely communicates with the pulmonary circulation. To assess the changes in the bronchial circulation in chronic pulmonary venous hypertension, fiberoptic bronchoscopy and right heart catheterization were performed in 31 patients with mitral stenosis. Nonpulsatile submucosal vessel dilatation, consistently seen in all patients and called the vessel dilatation score, was assessed visually by three independent bronchoscopists. The vessel dilatation score was correlated more closely with pulmonary artery wedge pressure (r = 0.687) (p less than 0.001) than to mean pulmonary artery pressure (r = 0.531) (p less than 0.01) and right atrial pressure (r = 0.178) (NS). The vessel dilatation score decreased after reduction of the left atrial load by surgery. These results suggest that the dilated vessels observed in patients with mitral stenosis are bronchial veins that are engorged secondary to increased blood flow via bronchopulmonary anastomoses.