Primary spontaneous pneumothorax: to pleurodese or not?

The yearly incidence of secondary spontaneous pneumothorax is 6·3 per 100 000 in men and 2·0 per 100 000 in women, whereas that of primary disease is 18·0-28·0 per 100 000 in men and 1·2-6·0 per 100 000 in women.1 The course of spontaneous pneumothorax is variable, and the recurrence rate is 25-54%; presence of lung disease is a major determinant of recurrence.1-3 Although primary spontaneous pneumothorax arises in patients without clinically apparent lung disease, most patients have emphysema-like changes, which can be shown by high-resolution chest CT.4 Bense and coworkers5 noted emphysema-like changes (blebs and bullae) bilaterally distributed in the upper lung zones in 22 of 27 (81%) non-smoking patients presenting with primary spontaneous pneumothorax, but no such changes were reported in healthy, never-smoker controls.5 The emphysema-like changes score of the affected lung was high in individuals with recurrent primary spontaneous pneumothoraces.6 The size and number of bullae (as detected by high-resolution CT), and body-mass index of less than 18·5 kg/m2 are predictors of recurrence of primary spontaneous pneumothorax, but age, sex, and smoking status are not.4,7,8 Emphysema-like changes can be assessed during thoracoscopy in accordance with the Vanderschueren classification (stage 1=normal pleura, stage 2=pleural adhesions, stage 3=blebs 2 cm).9 A systematic review showed that recurrence of spontaneous pneumothoraces was significantly more common after video-assisted thoracic surgery than after limited thoracotomy, because of inadequate exposure of the chest cavity and less resection of emphysema-like changes.10,11 Loubani12 and colleagues reported significantly higher recurrence in patients who underwent thoracoscopic staple bullectomy alone than in those who received bullectomy and tetracycline pleurodesis; this finding was attributed to the probable control by pleurodesis of many blebs that were difficult to resect.12 Tschopp and coworkers13 showed that thoracoscopic talc poudrage achieved 95% recurrence prevention; however, when bullae >2 cm were noted during thoracoscopy and left alone, four of ten patients experienced recurrence, and two of four needed surgery.13 The role of emphysema-like changes as a cause of primary spontaneous pneumothorax is debatable, because macroscopic emphysema-like changes were not noted during thoracotomy or thoracoscopy in about 50% of patients.14 Pleural porosity was proposed as ano