Pleurodesis: A novel experimental model

Background and objective: The experimental model of pleurodesis in rabbits has been useful in understanding the pathophysiology of the pleural inflammatory injury induced by several sclerosing agents. However, restrictions on the use of rabbits in laboratory investigation are making this model less accessible. The aim of this study was to present a new experimental model of pleurodesis in mice using talc or silver nitrate. Methods: Four groups of 10 C57BL/6 mice received talc 2 or 4 mg/g in 0.5 mL saline, or 0.025% or 0.05% silver nitrate in 0.5 mL H(2)O. After 28 days the animals were sacrificed, and the pleural cavity was opened and evaluated for evidence of macroscopic pleural adhesions and haemothorax (scores 0-4), atelectasis (scores 0-2), and microscopic pleural and alveolar inflammation and fibrosis (scores 0-4). Statistical analysis used ANOVA. Results: Silver nitrate 0.05% produced a more effective pleurodesis in mice than did 0.025% silver nitrate or talc 4 mg/g, with significant higher scores for pleural adhesions, microscopic pleural inflammation and fibrosis. Haemothorax, atelectasis, and microscopic alveolar inflammation and fibrosis were negligible in both groups. Conclusions: Both talc 4 mg/g and 0.05% silver nitrate produced an efficient pleurodesis in this experimental model in mice. This new model may overcome the restrictions on the use of large- and medium-sized animals in laboratory investigation and may open new fields of investigation with knockout mice.