Can a spontaneous pneumothorax occur during a Peroral Endoscopic Myotomy (POEM) procedure?

Pneumothorax During POEM Procedure: Risk Assessment and Management

Yes, spontaneous pneumothorax can occur during POEM procedures, with reported incidence rates of approximately 17% according to recent studies. 1

Incidence and Risk Factors

Pneumothorax is a recognized complication of Peroral Endoscopic Myotomy (POEM) that occurs due to the following mechanisms:

• Gas escaping from the submucosal tunnel into the mediastinum and pleural space
• CO2 or air insufflation during the procedure causing pleural breach
• Extension of myotomy into the pleural space

Key risk factors include:

• Use of air instead of CO2 for insufflation (significantly higher risk)
• Advanced patient age
• Longer procedure duration

Clinical Presentation and Detection

Pneumothorax during POEM may present with:

• Respiratory distress
• Oxygen desaturation
• Hemodynamic instability
• Subcutaneous emphysema (occurs in 28-55% of cases) 1, 2

Most pneumothoraces associated with POEM are detected on routine post-procedure imaging rather than from clinical symptoms. In a large retrospective study of 300 patients, only 5.6% of patients with radiologically confirmed pneumothorax required intervention based on clinical symptoms. 1

Prevention Strategies

To minimize pneumothorax risk during POEM:

1. Use CO2 instead of air for insufflation - This is mandatory as CO2 is more rapidly absorbed than air and significantly reduces pneumothorax risk 1
2. Maintain low gas flow and pressure settings
3. Ensure proper submucosal tunnel creation technique
4. Avoid extending the myotomy too far laterally

Management Algorithm

When pneumothorax occurs during or after POEM:

1. For asymptomatic, small pneumothorax (<3 cm apex-to-cupola distance):

   • Conservative management with close observation
   • Supplemental oxygen as needed
   • Serial chest imaging to monitor progression

2. For symptomatic or large pneumothorax (≥3 cm apex-to-cupola distance):

   • Small-bore catheter (≤14F) or chest tube (16F-22F) placement
   • Connect to Heimlich valve or water seal device
   • Apply suction if lung fails to re-expand quickly

3. For persistent air leak (>5-7 days):

   • Consider chemical pleurodesis with talc slurry
   • Early thoracic surgical consultation (within 3-5 days)

Important Considerations

• Most pneumothoraces associated with POEM are clinically insignificant and resolve with conservative management 1, 2
• Routine chest CT after POEM is probably not warranted due to the high rate of minor, clinically irrelevant findings 1
• Other common post-POEM findings include pneumomediastinum (48%), pneumoperitoneum (37%), pleural effusion (66%), and pneumonitis (52%) 1

Clinical Pearls and Pitfalls

• Pearl: Most pneumothoraces during POEM can be managed conservatively without additional surgical intervention 2
• Pitfall: Relying solely on CT imaging to detect clinically significant pneumothorax may lead to unnecessary interventions
• Pearl: Using CO2 instead of air for insufflation significantly reduces pneumothorax risk 1
• Pitfall: Failing to recognize that subcutaneous emphysema, while common (28-55% of cases), does not necessarily indicate pneumothorax requiring intervention 1, 2

The overall complication profile of POEM is favorable, with most complications being managed successfully with traditional treatment approaches and without requiring additional surgery 2.