Reframing spontaneous pneumothorax: A practical guide to the PLEX variant classification

The conventional primary-secondary classification of spontaneous pneumothorax fails to capture the complexity encountered during thoracoscopic surgery, where CT imaging often misses subtle apical scarring, early emphysematous changes, or fibrotic, noncompliant lung tissue. To provide a more operative-relevant clinical framework, we hereby propose the PLEX Classification, based on Pattern of lung abnormality, Location of leak and lung reserve, Extent of disease, and eXpected surgical complexity and surgical outcome. This system categorizes pneumothorax into four different variants: Type I (apical vulnerability pneumothorax), Type II (multibullous pneumothorax), Type III (emphysematous pneumothorax), and Type IV (fibrotic lung pneumothorax). Applied to 710 surgeries, PLEX demonstrated a clear gradient of increasing surgical difficulty and complications from Type I to Type IV. PLEX offers a pragmatic, surgically actionable system for planning, communication, as well as outcome prediction.