Abstract
OBJECTIVES: To compare the extent of pleural inflammation and fibrosis induced by autologous blood vs talc pleurodesis in an exploratory experimental model and evaluate effects of postoperative non-steroidal anti-inflammatory analgesics on pleurodesis formation. METHODS: Twenty-eight Sprague Dawley rats underwent intrapleural instillation of autologous blood on one side and talc on the contralateral side. They were sacrificed at 2, 4, 6, 15, or 30 days for macroscopic and histopathological analysis. Eight animals in the late euthanasia groups received oral Ibuprofen postoperatively. A pathologist, who was blinded to the interventions assessed all animals for macroscopic adhesions in the chest as well as microscopic evaluation for inflammation and fibrosis. RESULTS: We found no significant differences between autologous blood and talc regarding macroscopic adhesion scores, or grading of inflammation and fibrosis. The inflammatory response peaked earlier after autologous blood compared with talc. Fibrosis progressively increased after both interventions. Ibuprofen reduced inflammation and fibrosis in both types of pleurodesis. Statistically significant reductions in fibrosis were seen after 15 days in the talc group (P = .008) and after 30 days in the autologous blood group (P = .024). CONCLUSIONS: Autologous blood and talc pleurodesis induce comparable inflammatory responses and fibrosis in this experimental model suggesting that the mechanism of autologous blood patch for prolonged air leakage is not just a mechanical plug effect. Ibuprofen reduced all inflammatory responses after both interventions suggesting that non-steroidal anti-inflammatory drugs may impair pleurodesis formation.