Fluorescein-enhanced autofluorescence thoracoscopy in patients with primary spontaneous pneumothorax and normal subjects.

Rationale: The exact site(s) and pathophysiology of air leakage in patients with primary spontaneous pneumothorax (PSP) are unknown. In one patient with PSP, fluorescein-enhanced autofluorescence thoracoscopy (FEAT) has shown areas of parenchymal abnormality unnoticed during white light thoracoscopy (WILT). Objectives: To prospectively perform and compare WILT and FEAT in patients with spontaneous pneumothorax and in normal subjects. Methods: One-time FEAT and WILT inspection with systematic mapping of semiquantified lesions in 12 consecutive patients with PSP was compared with one-time FEAT and WILT during sequential bilateral thoracoscopy in 17 control subjects. Results: WILT abnormalities (anthracosis, cobblestone malformation, and blebs/bullae) were more prevalent in PSP. FEAT, however, showed high-grade lesions in PSP only, which often were present at areas that were normal, or that only showed anthracosis at WILT. When blebs/bullae were present, bleb-associated FEAT abnormalities were only present in two. Actual fluorescein leakage was seen in two patients with PSP. Conclusions: Lungs in patients with PSP show significantly more abnormalities at WILT when compared with normal subjects. High-grade FEAT lesions were exclusively present in PSP, and predominantly at lung zones that appeared normal at white light inspection. These findings suggest that significant parenchymal abnormalities are not limited to lesions visible during WILT, such as blebs and bullae.