Release of growth factors after mechanical and chemical pleurodesis for treatment of malignant pleural effusion: a randomized control study
Objectives: To compare thoracoscopic mechanical pleurodesis (TMP) and chemical pleurodesis with talcum (CPT) through the analysis of growth factors (GF) release in the first 48 hours. GF are key inducers of fibrosis but can also mediate inflammatory responses resulting in increasing pleural effusion and ARDS. By this, we explain and address effectiveness, safety and tolerance issues of pleurodesis.
Methods: A prospective randomized study included 36 consecutive female patients with breast carcinoma and malignant pleural effusion in an intention-to-treat analysis. We treated 18 patients by means of TMP and 18 patients by CPT using 5g of talc slurry applied over a chest tube. We gathered pleural fluid and serum samples in the following 48 hour under a dedicated protocol and tested them for GF levels.
Results: Maximal serum VEGF level after chemical pleurodesis was 11930 pg/ml and after mechanical, it was 2687 pg/ml. Median pleural levels of TGF β1 were higher after performing mechanical pleurodesis - 4814,00 (95% CI: 2726,51 - 7292,94) pg/ml when compared to those after performing chemical pleurodesis - 1976,50 (95% CI: 1659,82 - 5136,26) pg/ml. The difference did not reach statistical significance, however TGF β1 and VEGF remain the most interesting parameters for future research.
Conclusions: Our study showed significant increase in serum VEGF levels after chemical pleurodesis and more pronounced increase in pleural fluid level of FGF α and β and TGF β1 after mechanical pleurodesis. Considering the mechanisms of growth factors action, we conclude that the mechanical irritation is more effective, better-tolerated and safer method than chemical pleurodesis.