Medical Thoracoscopy with versus without Prior Artificial Pneumothorax for Patients with Minimal or Absent Pleural Effusion

Background: Thoracoscopy guidelines recommend inducing artificial pneumothorax before medical thoracoscopy in patients with minimal or absent pleural effusion. Recent single-arm studies have demonstrated that non-artificial pneumothorax approaches reduce operative time and complication rates compared with artificial pneumothorax techniques in these patients. However, there is a lack of trials comparing the effectiveness and safety of performing artificial pneumothorax versus not performing it in these cases. Research question: For patients with minimal or absent pleural effusion, is non-artificial pneumothorax (non-AP) non-inferior to artificial pneumothorax (AP) in terms of pleural access success rate? Study design and methods: In this multicenter randomized non-inferiority trial, patients with minimal or absent pleural effusion requiring medical thoracoscopy were randomized 1:1 to either an AP group or a non-AP group. The primary outcome was pleural access success rate, with a non-inferiority margin of -10% (non-AP group minus AP group). Secondary outcomes included pathological confirmation rates, complication rates, operation length, air leak duration, drain removal time, chest pain scores, and 90-day mortality. Results: A total of 204 participants were equally allocated to the AP group (n=102) and the non-AP group (n=102). Pleural access success rate was 95.0% in the non-AP group and 78.4% in the AP group (difference 16.6% [one-sided lower 97.5% CI 7.6%]; P<0.001 for non-inferiority). Complications occurred in 14.9% of non-AP and 17.6% of AP patients (difference 2.7% [95% CI -12.9% to 7.3%]; P = 0.589). Interpretation: For patients with minimal or absent pleural effusion, artificial pneumothorax is not necessary before performing medical thoracoscopy.