The role of bronchial circulation in lung abscess

We studied the anatomy of bronchial circulation in 6 sheep with multiple lung abscesses. After anesthesia, the animals were heparinized and exsanguinated. The bronchial artery, pulmonary artery, and tracheobronchial tree were filled with Batson's solution of varying colors. The cast was dissected and the anatomy was studied with a dissecting microscope as well as a scanning electron-microscope. The bronchial arteries were found to be enlarged and hypertrophied in all infected animals. The abscess cavities were surrounded with a dense vascular plexus that was being supplied exclusively by the bronchial arteries. The pulmonary capillaries were sparse and were filled entirely by the bronchial artery. The pulmonary circulation did not supply the walls of lung abscess cavity. Our findings indicate that the bronchial circulation may be more important than the pulmonary circulation in resolution and repair after certain lung infections.