Corynebacterium parvum versus tetracycline as pleural sclerosing agents in rabbits

Pleurodesis by erythromycin, tetracycline, Aerosil™ 200, and erythromycin plus Aerosil™ 200 in a rat model: a preliminary study

Background

None of the current pleurodesing agents fulfil all the criteria for best pleural sclerosant. Therefore, the search for the ideal agent for chemical pleurodesis still continues. The aim of the present study was to compare the effectiveness of erythromycin, tetracycline, Aerosil™ 200 (hydrophilic fumed amorphous silica), and erythromycin plus Aerosil™ 200 in producing pleurodesis in rats. In the present study, talc was not used as a pleurodesing agent due to an unavailability of its sterile and pure form in Iran.

Methods

Overall, 75 adult male Spraque-Dawley rats were randomized to 5 treatment groups. Each group received an intrapleural injection via 5 Fr Silastic tubes of one of the following sterile agents: 35mg/kg erythromycin in 2 ml of saline, 35mg/kg tetracycline in 2 ml of saline, 35mg/kg Aerosil™ 200 in 2ml of saline, erythromycin (35mg/kg in 2 ml of saline) plus Aerosil™ 200 (35mg/kg in 2 ml of saline), or 2 ml of saline as a control. The animals were euthanized and necropsied 30 days after injection. The pleurae were assessed for macroscopic and microscopic evidence of surrounding inflammation and fibrosis.

Results

The median macroscopic score in the Aerosil™ 200 group was significantly higher than that in the erythromycin group (P < 0.005). The median microscopic score in the erythromycin group was significantly lower than that in the Aerosil™ 200 and erythromycin plus Aerosil™ 200 groups (P < 0.005). Furthermore, maximum and minimum pleural fibrosis was observed in the erythromycin plus Aerosil™ 200 and erythromycin groups, respectively (P < 0.05).

Conclusion

This study suggests that Aerosil™ 200 with or without erythromycin may be more potent pleurodesis agent than erythromycin and tetracycline.

Efficacy and safety of iodopovidone in chemical pleurodesis: A meta-analysis of observational studies

The search for an 'ideal' agent for pleurodesis continues. Iodopovidone is a topical antiseptic and has been shown to be safe and effective in many studies. The aim of this study was to evaluate the efficacy and safety of iodopovidone as an agent for chemical pleurodesis. We performed a systematic review of all the observational trials which have used iodopovidone for chemical pleurodesis. Six studies including 265 patients who had undergone chemical pleurodesis with iodopovidone were included for this analysis. Iodopovidone was used for variety of indications, which included pleural effusion (157 patients), and pneumothorax (108 patients). Pleurodesis was performed through tube thoracostomy in 144 patients and through thoracoscopy in 121 patients. The success rate of pleurodesis varied from 64.2% to 100%, and summary success rate of all the studies was 90.6% (95% confidence intervals [CI], 86.4-93.8). The success rate was independent for the procedure (tube thoracostomy [126/144; 87.5%, 95% CI 80.9-92.4] or thoracoscopy [114/121; 94.2%, 95% CI 88.4-97.6]) used for performing pleurodesis or for the indication (pleural effusion [139/157; 88.5%, 95% CI 82.5-93.1] or pneumothorax [101/108; 93.5%, 95% CI 87.1-97.4]). The only significant complication reported was chest pain of varying degree. Systemic hypotension was reported in three patients in only one study. There were no deaths related to chemical pleurodesis with iodopovidone. Overall, this review supports the safety and efficacy of iodopovidone as an agent for chemical pleurodesis in cases of recurrent pleural effusions and pneumothoraces regardless of their etiology.