Diagnosis and management of left main stem bronchus compression.

There are four major variants of congenital vascular tracheal compression: innominate artery, aberrant subclavian, aorta or aortic arch anomaly, and pulmonary artery sling. These forms of vascular compression typically involve the trachea and/or the right main stem bronchus. We present eight cases of congenital vascular compression involving the left main stem bronchus. These cases represent a poorly understood variant of vascular tracheal compression. This variant represents approximately 10% of our pediatric tracheobronchial compression or stenosis patients. The finding, both noted endoscopically and now illustrated by magnetic resonance imaging, is caused by compression of the left main stem bronchus between the descending aorta and a portion of the pulmonary artery. Frequently, the descending aorta is in an abnormal anterior position with relation to the thoracic spine. Recognition of this entity is important in our experience and has influenced clinical management. In four of eight children, it required a surgical procedure directed toward the relief of the left main stem compression.