What is pleurodesis?

What is Pleurodesis

Pleurodesis is a medical procedure that creates permanent adhesion between the visceral and parietal pleural layers to obliterate the pleural space, thereby preventing recurrent accumulation of air (pneumothorax) or fluid (pleural effusion). 1, 2

Mechanism of Action

The procedure works through several biological pathways that ultimately fuse the two pleural surfaces together:

• Mechanical apposition of the visceral and parietal pleura is the essential first step, requiring complete lung re-expansion before the procedure can succeed 1, 3, 2
• Diffuse inflammation is triggered by the sclerosing agent, with pleural mesothelial cells serving as the primary target and releasing key mediators including interleukin-8, transforming growth factor-β, and basic fibroblast growth factor 2
• Coagulation-fibrinolysis imbalance develops in the pleural space, favoring formation of fibrin adhesions that bridge the pleural surfaces 2, 4
• Fibroblast recruitment and proliferation occurs, followed by collagen deposition that creates permanent fibrous adhesions between the pleural layers 2, 4

Methods of Pleurodesis

There are two main approaches, with surgical methods generally achieving superior outcomes:

Surgical Pleurodesis

• Video-assisted thoracoscopic surgery (VATS) is the preferred minimally invasive approach, offering shorter operating time, shorter drainage time, fewer complications, and shorter hospital stay compared to open thoracotomy 1, 5
• Mechanical pleural abrasion creates mechanical irritation with recurrence rates of approximately 2.3% 1
• Pleurectomy involves removal of parietal pleura and achieves the lowest recurrence rates (0.4%), though with potentially higher morbidity, and is reserved for recurrent pneumothorax or malignant pleural effusion 1

Chemical Pleurodesis

• Talc pleurodesis is the most effective chemical agent with success rates of 85-92%, available as talc slurry (instilled through chest tube) or talc poudrage (insufflated during thoracoscopy), with poudrage generally preferred due to higher success rates and lower complications 1, 4
• Doxycycline/Tetracycline serves as an alternative with 72-80% success rates but higher recurrence rates than talc 1, 3
• Bleomycin achieves 54-61% success rates and is administered at 60 units as a single intrapleural bolus dose 3, 6

Primary Indications

The American College of Chest Physicians recommends pleurodesis for three main clinical scenarios:

• Recurrent pneumothorax, particularly after first episode of secondary pneumothorax or in high-risk professions (pilots, divers) 1, 5
• Malignant pleural effusion in symptomatic patients whose dyspnea improves with therapeutic thoracentesis and who have sufficient life expectancy to benefit 1, 3
• Spontaneous hemothorax with recurrence risk 1

Absolute Contraindications

Pleurodesis should never be performed in these situations:

• Trapped lung or inability to achieve complete lung re-expansion, as pleural surfaces cannot appose 1, 3
• Mainstem bronchial obstruction, which prevents necessary lung expansion 1, 3
• Active pleural infection, due to high complication risk and low success rates 1, 3

Critical Success Factors

Several conditions must be met for pleurodesis to work effectively:

• Complete lung re-expansion must be confirmed on chest radiograph before proceeding, as this is essential for pleural surface apposition 1, 3, 4
• Minimal chest tube drainage (less than 100-150 mL per 24 hours) should be achieved before chemical pleurodesis 3, 6
• Pleural fluid pH above 7.20 predicts better success, as low pH indicates trapped lung and correlates with pleurodesis failure 4
• Avoid corticosteroids and NSAIDs at the time of pleurodesis, as they reduce pleural inflammatory reaction and increase failure rates 3

Common Pitfalls

• Attempting pleurodesis with incomplete lung expansion is the most common cause of failure—always verify full re-expansion radiographically before instilling sclerosant 3, 4
• Using BiPAP or positive pressure ventilation during active pneumothorax increases risk of tension pneumothorax and should be withheld until complete resolution 1, 5
• Draining large effusions too rapidly (more than 1-1.5 L at once) can cause re-expansion pulmonary edema 3
• High tumor burden in malignant effusions reduces normal mesothelial cells and decreases response to sclerosing agents, leading to higher failure rates 2