ABSTRACT
PURPOSE: Talc remains a commonly used agent for pleurodesis malignant pleural effusion. Nevertheless, it is associated with a 3-9% incidence of pulmonary reactions ranging from simple pneumonitis to acute respiratory distress syndrome (ARDS). The underlying lung pathology and the size and rate of talc particle dissemination have been implicated as the cause of these complications. There seems to be an acknowledged lack of evidence regarding detailed very early intrathoracic talc particle migration. MATERIALS AND METHODS: Thirty white male New Zealand rabbits underwent experimental pleurodesis and were randomly assigned to 3 (A, B, C) study groups (10 in each group). Rabbits were sacrificed 6, 12 and 18 h after talc administration. Samples from both lungs, mediastinum and parietal pleura were obtained. The number of talc crystals (m) deposited was counted and averaged along all slices of the various tissue samples. RESULTS: A high degree of early talc deposition and subsequent epithelial injury in all examined tissues was observed. Diffuse talc deposition occurred in both lungs, but in a different manner. On the side of talc administration, talc particles were deposited in a time-dependent fashion. On the contralateral side, talc was rapidly deposited during the first hours after the procedure, then the rate of deposition decreased, and increased again between 12 and 18 h after the procedure. CONCLUSION: Large-sized talc particles are deposited on both lungs very early after pleurodesis. At the same time inflammatory pulmonary changes appear bilaterally. Despite contradicting data in the literature, these findings should always be kept in mind when performing this procedure in high risk patients.
