The anatomy of left bronchus syndrome.

This explanation of the previously described left bronchus syndrome (Ashour et al., 1990, Thorax, 45:210-212) is based on a prospective study of 17 additional cases with unilateral lung destruction. It is likely that the anatomic peculiarities of the left main bronchus predispose the left lung to more frequent bronchial obstruction and hemodynamic changes than the right. Broncho-pulmonary shunt formation and retrograde filling of the pulmonary artery most likely lead to increased oxygen tension and impaired lymph flow in the entire lung, thus spreading tuberculosis in the lung and ultimately leading to left lung destruction.