Objective: To evaluate the results of thoracoscopy for the treatment of pleural empyema in pediatric patients. Methods: A retrospective study of 117 patients who underwent mediastinoscopy or video-assisted thoracoscopy for pleural empyema treatment. General anesthesia and single-lumen oral intubation were used. Surgery was indicated when there was pleural effusion and no clinical and radiological response to clinical treatment (antibiotics, physiotherapy and thoracocentesis) or severe sepsis, together with loculated pleural effusion (confirmed through ultrasound or computed tomography of the chest). Results: Between February of 1983 and July of 2006, 117 thoracoscopies were performed in patients ranging in age from 5 months to 17 years (mean, 4 years). Mean time for thoracic drainage was 9 days (range, 2-33 days), and mean period of hospitalization was 16.4 days (range, 4 to 49 days). One patient (0.8%) died after surgery, and persistent fistula was observed in 33 patients (28%). In 7 cases (6%), open thoracotomy with pulmonary decortication was performed due to the disposition of the empyema. Conclusions: Management of pleural empyema in this age bracket is still controversial, and surgical indication is often delayed, particularly when there are multiple loculations or severe sepsis. Early thoracoscopy yields a better clinical outcome for pediatric patients with pleural empyema, with apparent decreased morbidity and mortality, earlier chest tube removal, earlier hospital discharge and improved response to antibiotic therapy.

Keywords: Empyema, pleural; Pediatrics/instrumentation; Thoracoscopy; Thoracic surgery, video-assisted.

Objective: The reproduction of an experimental emphysema model in rats by intratracheal instillation of papain was proposed for the evaluation of lung volume reduction surgeries. Method: The study used orotracheal instillation of papain (20 mg/kg) dissolved in 0.9% saline solution. Forty days after instillation, animals underwent mechanical ventilation. Elastance and resistance of the respiratory system were measured, and the rats were sacrificed by having their lungs removed. The pulmonary tissue of the animals was qualitatively analyzed with hematoxylineosin staining and submitted to morphometric analysis for the measurement of the mean alveolar diameter. The pulmonary tissue was also subjected to resorcin-fuchsin staining for the identification of elastic fibers, which were quantified in alveolar septa by digital imaging. Results: In the animals instilled with papain, the histological analysis of the lungs showed pan-acinar emphysema, with rupture of alveolar septa and hyperdistention. Morphometric analysis showed higher mean values for mean alveolar diameter in the lungs of the animals submitted to papain (149.08 μm and 100.56 μm) as compared to the group receiving saline solution (64.08 μm and 75.90 μm). The quantification of elastic fibers of alveolar septa of papain-treated animals was 70% lower than in the animals receiving saline solution. Mechanic ventilation did not show differences in respiratory system resistance of animals receiving papain or saline solution. Respiratory system elastance was lower in the group receiving papain than in the group receiving saline solution, showing a functional status compatible with pulmonary emphysema, with decreased elasticity of the pulmonary tissue. Conclusion: The reproduction of an experimental model of pan-acinar pulmonary emphysema in rats was achieved by papain instillation through the respiratory tree with functional and morphologic evidences.

Keywords: Pulmonary emphysema. Experimental model. Papain. Rats. Drug instillations.