Effect of diclofenac on experimental pleurodesis induced by tetracycline in rabbits

Background and Objective: Pleurodesis is a frequently preferred procedure in thoracic surgery, and many factors may affect the process. We aimed to determine whether the administration of systemic diclofenac sodium diminishes the effectiveness of the pleurodesis induced by intrapleural tetracycline in rabbits. Methods: Twelve male New Zealand rabbits that received tetracycline 35 mg/kg intrapleurally were allocated into two groups. The first group (diclofenac group, n=6) received 2 mg/kg diclofenac sodium intramuscularly for 10 days, and the second group (control group, n=6) received acetaminophen 30 mg/kg orally for 10 days after the pleurodesis procedure. The rabbits were sacrificed after 28 days, and the pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of fibrosis, inflammation, and collagenization. Results: The mean macroscopic pleurodesis score of the diclofenac group was 2.16 +/- 0.40 compared with 2.83 +/- 0.40 in the control group (p=.027). The mean microscopic pleurodesis score of the diclofenac group was 2.3 +/- 1.03, whereas it was 3.5 +/- 0.54 in the control group (p=.045). Conclusion: The administration of diclofenac sodium for 10 days following tetracycline pleurodesis reduces the effectiveness of pleurodesis in rabbits.