Degree Of Pleurodesis Research Articles

Monoclonal antibodies anti-TGFβ1 and anti-VEGF inhibit the experimental pleurodesis induced by silver nitrate

Background. The mechanisms underlying pleural inflammation and pleurodesis are poorly understood. We hypothesized that the cytokines transforming growth factor β (TGFβ1) and vascular endothelial growth factor (VEGF) play a major role in pleurodesis after intrapleural silver nitrate (SN) injection. Method. Forty rabbits received intrapleurally 0.5% SN alone or 0.5% SN + anti-TGFβ1, anti-IL-8, or anti-VEGF. After 28 days, the animals were euthanized and macroscopic pleural adhesions, microscopic pleural fibrosis, and collagen deposition were analyzed for characterization of the degree of pleurodesis (scores 0–4). Results. Scores of pleural adhesions, pleural fibrosis, total collagen, and thin collagen fibers deposition after 28 days were significantly lower for 0.5% SN + anti-TGFβ1 and 0.5% SN + anti-VEGF. Significant correlations were found between macroscopic adhesion and microscopic pleural fibrosis with total collagen and thin collagen fibers. Conclusions. We conclude that both TGFβ1 and VEGF, but not IL-8, mediate the pleural inflammatory response and pleurodesis induced by SN.

A comparison of the efficacies of heterologous blood, rifamycin, and talc as pleural sclerosants in rabbits: An experimental study

Background: In this study, we aimed to investigate the efficacy of rifamycin pleurodesis in rabbits. Methods: A total of 21 male New Zealand-type albino rabbits with an average weight of 3433 grams, were used in the study. One rabbit was used for blood supply. The other 20 rabbits were divided into four groups, including the control group, the heterologous blood group, the rifamycin group, and the talc group. Distilled water, heterologous fresh blood, rifamycin, and sterile liquid talc were administered through the catheter to the left hemithorax of rabbits. The rabbits were sacrificed using high-dose anesthesia on day 28. The pleural spaces were grossly assessed for evidence of pleurodesis and microscopic thickness of the pleura, and evidence of inflammation and fibrosis were examined. The degree of pleurodesis was rated on a scale of 0 to 4. Results: No statistically significant differences were observed between the control and heterologous blood groups at the macroscopic and microscopic level (p>0.05). The degree of pleurodesis in the talc and rifamycin groups was higher than in the control and heterologous blood group (p=0.04). No significant difference was observed between the talc and rifamycin groups in terms of macroscopic and microscopic examination (p>0.05). The median values of fibrosis thickness of the control, heterologous blood, rifamycin, and talc groups were 10 (10-29), 26 (10-71), 312 (264-351) and 304 (238-331) μm, respectively. Conclusion: The efficacy of rifamycin pleurodesis in rabbits was microscopically and macroscopically similar to the talc group and superior to the control and heterologous blood group.

Transforming growth factor β2 (TGFβ2) produces effective pleurodesis in sheep with no systemic complications

BACKGROUNDWe have recently shown that transforming growth factor (TGF)β2induces effective pleurodesis in rabbits. However, rabbits have a thin pleura while humans have a thick visceral pleura. The effect of intrapleural...

Acute and Chronic Pleural Changes after the Intrapleural Instillation of Mitoxantrone in Rabbits

A previous study demonstrated that the intrapleural injection of 2 mg/kg mitoxantrone in rabbits resulted in a degree of pleurodesis which is comparable to that seen after 35 mg/kg tetracycline but that the animals had a high mortality rate after this dose of mitoxantrone. The objective of the present study was to assess the acute pleural fluid findings, the acute gross and microscopic pleural findings, and the chronic gross and microscopic findings in rabbits that received mitoxantrone. Mitoxantrone, 1.5 mg/kg, was instilled intrapleurally in 70 lightly anesthetized male rabbits. Groups of rabbits were sacrificed 1, 2, 4, 7, 15, 28, and 60 days after the injection. The intrapleural injection of mitoxantrone resulted in an exudative effusion on day 1. The pleural fluid contained predominantly neutrophils and had a mean lactate dehydrogenase (LDH) level that exceeded 4,000 IU/liter. Over the following week the volume of fluid diminished, the predominant cell became the macrophage, and the LDH levels decreased to less than 400 IU/liter. Macroscopic examination of the pleural space revealed that the mean degree of pleurodesis increased progressively over the 60-day observation period. With microscopy, the mean degree of pleural fibrosis also increased progressively. There were also substantial fibrosis and inflammation of the underlying lung and the contralateral lung. The mortality rates were low in the first 28 days (3/70) but subsequently increased and exceeded 80% in the period between 60 and 120 days. This experimental model of pleurodesis should be useful in future studies directed toward uncovering the mechanisms of pleurodesis.

Talc Slurry Is an Effective Pleural Sclerosant in Rabbits

Insufflated talc is probably the most effective agent for creating a pleurodesis both in the clinical situation and in animals. However, the insufflation of talc requires an invasive procedure such as thoracoscopy or thoracotomy. Recently, there have been reports that talc in a slurry was effective in the clinical situation. The objective of this project was to determine whether talc in a slurry at varying doses is an effective sclerosant in an experimental model in rabbits. Talc, 50, 100, 200, and 400 mg/kg, in a 2-mL slurry was injected intrapleurally through a small catheter in male rabbits. Eleven rabbits received each dose. Twenty-eight days after the instillation, the animals were killed. The pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of fibrosis and inflammation. The degree of pleurodesis (on a scale of 0 to 4) after the injection of 50, 100, 200, and 400 mg/kg of talc was 1.1 +/- 0.9, 1.5 +/- 1.1, 2.7 +/- 0.6, and 3.4 +/- 0.5, respectively. The degree of microscopic fibrosis similarly increased with increasing doses of talc. These scores were similar to those we have reported with the tetracycline derivatives. In contrast to the results with tetracycline derivatives, none of the rabbits developed fibrothorax or hemothorax. From this study, we conclude that talc in a slurry is a very effective pleural sclerosant in rabbits and does not produce hemothoraces as do the tetracycline derivatives.