“Alveolarization” of Tantalum Powder in Experimental Bronchography and the Clearance of Inhaled Particles from the Lung

Bronchography employing tantalum powder insufflation was performed in healthy dogs, dogs with pulmonary infections, and dogs in which increased pulmonary secretions were simulated by carboxymethylcellulose solutions. Aspiration of tantalum-laden secretions into the peripheral airways was observed. Serial radiographs showed little change after 48 hours. Upon reaching the alveoli, metal particles were phagocytized and incorporated into peribronchiolar dust macules or thickened septa; some were later transported to the hilar lymph nodes. No cytotoxic reaction was observed. Prolonged pulmonary opacification may result from the use of tantalum powder in the lower airways.