TALC SLURRY PLEURODESIS - PEURAL FLUID AND HISTOLOGIC ANALYSIS

Although talc slurry pleurodesis is effective for control of malignant pleural effusions and recurrent pneumothorax, the mechanisms of pleur odesis remain incompletely defined. We instilled 70 mg/kg of sterile a sbestos-free talc slurry into the pleural space of New Zealand white r abbits and studied the inflammatory response at 1, 2, 3, 7, 15, 30, 60 , 90, and 120 days by observing pleural fluid and histologic character istics. Talc slurry caused mesothelial denudement and an exudative neu trophilic pleural effusion that resolved after 48 h. A transient monon uclear vasculitis was seen within the lung at 1, 2, and 3 days after i nstillation. Pleural adhesions were minimal and did not increase in nu mber over time. Talc was found outside of the pleural space in mediast inal lymph nodes (4 of 23 animals examined), kidney (1 of 6), and sple en (4 of 10). The predominant cause of pleurodesis with talc slurry in stillation is an acute pleural injury similar to the tetracycline clas s agents.