Determination of zeolite pleurodesis effect and safety in experimental rabbit model and comparison with talc powder

Pleural cavity, which is the small space between visceral and parietal pleurae, is filled with a small amount of fluid called pleural fluid. Accumulation of an abnormal amount of pleural fluid between the two pleurae is called pleural effusion, treatment of which includes the drainage of excessive fluid, surgery, and pleurodesis. Pleurodesis is the procedure of elimination of pleural space for prevention of the relapse in pleural effusion and pneumothorax, as well as treating pneumothorax. Chemical pleurodesis is performed by application of various reagents including talc. Zeolites, which are microporous tectosilicates found in nature as mineral, can be synthesized under laboratory conditions and have a range of medical applications. The aim of this study was to investigate the pleurodesis effect and safety of zeolite in comparison to talc powder. A total of fifteen male New Zealand rabbits were divided into three groups consisting of five animals and were administered intrapleurally with one of the three vehicles; saline (2 mL physiological saline), talc (400 mg/kg in vehicle), or zeolite (400 mg/kg in vehicle). On postoperative day 26, the animals underwent computerized tomography (CT) imaging and on day 28, the animals were sacrificed and lung tissues were collected for histopathological examination. CT images were obtained for each animal to prove full expansion of lungs postoperatively, as well as to detect the presence of any significant parenchymal infiltration or atelectasis. According to the histopatological results, we determined that zeolite and talc produced similar pleurodesic effects. Subacute toxicity and mutagenicity of zeolite were assessed according to International Organization for Standardization (ISO) standards and no toxicity and mutagenicity were observed. According to the results we obtained from the study, we suggest that zeolite can be used as a safe pleurodesic agent.