Mechanisms of Pleurodesis

Pleurodesis aims to obliterate the pleural space by producing extensive adhesion of the visceral and parietal pleura, in order to control relapse of either pleural effusions (mostly malignant) or pneumothorax. A tight and complete apposition between the two pleural layers is a necessary condition to obtain a successful pleurodesis, but – besides this mechanical aspect – there are many biological mechanisms that appear to be common to most of the sclerosing agents currently used. Following intrapleural application of the sclerosing agent, diffuse inflammation, pleural coagulation-fibrinolysis imbalance (favoring the formation of fibrin adhesions), recruitment and subsequent proliferation of fibroblasts, and collagen production are findings in the pleural space. The pleural mesothelial lining is the primary target for the sclerosant and plays a pivotal role in the whole pleurodesis process, including the release of several mediators like interleukin-8, transforming growth factorand basic fibroblast growth factor. When the tumor burden is high, normal mesothelial cells are scarce, and consequently the response to the sclerosing agent is decreased, leading to failure of pleurodesis. Also, the type of tumor in the pleural cavity may also affect the outcome of pleurodesis (diffuse malignant mesothelioma and metastatic lung carcinomas have a poorPublished online: January 20, 2012 Francisco Rodriguez-Panadero, MD Edificio del Instituto de Biomedicina de Sevilla, Lab 120 Campus H.U. Virgen del Rocio, Avda. Manuel Siurot s/n ES–41013 Sevilla (Spain) Tel. +34 955 923 063, E-Mail frodriguezpan @ gmail.com or frpanad @ ono.com © 2012 S. Karger AG, Basel 0025–7931/12/0832–0091$38.00/0 Accessible online at: www.karger.com/res Previous article in this series: 1. Anevlavis S, Tzouvelekis A, Bouros D: Mechanisms of pleural involvement in orphan diseases. Respiration 2012;83:5–12. D ow nl oa de d by : 54 .7 0. 40 .1 1 11 /1 9/ 20 17 6 :2 2: 56 P M