Pleurodesis is a medical procedure used to treat conditions like pleural effusion or pneumothorax, where fluid or air accumulates in the space between the lungs and the chest wall. The goal is to adhere the pleura, the two layers of tissue surrounding the lungs, to prevent further accumulation of fluid or air. During the procedure, a substance, often a sclerosing agent like talc, is introduced into the pleural space. This irritates the pleura, causing them to stick together. Pleurodesis can be performed through a chest tube or during thoracoscopic surgery, depending on the patient's condition and the physician's recommendation.