A retrospective analysis of treatment selection and risk factors of treatment failure and recurrence in patients with spontaneous pneumothorax.

Background:Conservative observation with/without oxygen supplementation, aspiration, or tube drainage is selected as an initial treatment for spontaneous pneumothorax. In this study, we examined the efficacy of initial management for cessation of air leak and prevention of recurrence, with consideration of the degree of lung collapse. Methods:Spontaneous pneumothorax in patients who underwent initial management in our institute between January 2006 and December 2015 were included in this retrospective, single-institutional study. Multivariate analyses were conducted to identify risk factors related to the treatment failure after initial treatment and those related to ipsilateral recurrence after last treatment. Results:Of 668 episodes of 522 patients, 198 events were initially treated by observation, 22 by aspiration, and 448 by tube drainage. Successive outcome for cessation of air leak in initial treatment was achieved in 170 (85.9%), 18 (81.8%), and 289 (64.5%) events, respectively. In the multivariate analysis for predicting failure after first treatment, previous episode of ipsilateral pneumothorax [odds ratio (OR) 1.9; 95% confidence interval (CI): 1.3-2.9; P<0.01], high degree of lung collapse (OR 2.1; 95% CI: 1.1-4.2; P=0.032), and bulla formation (OR 2.6; 95% CI: 1.7-4.1; P<0.0001) were the significant risk factors for treatment failure. Recurrence of ipsilateral pneumothorax was observed in 126 (18.9%) cases: 18 of 153 cases (11.8%) in the observation group, 3 of 18 cases in the aspiration group (16.7%), 67 of 262 cases in the tube drainage group (25.6%), 15 of 63 cases in the pleurodesis group (23.8%), and 23 of 170 cases in the surgery group (13.5%). In the multivariate analysis for predicting recurrence, previous episode of ipsilateral pneumothorax was a significant risk factor [hazard ratio (HR) 1.8; 95% CI: 1.2-2.5; P<0.001]. Conclusions:Predictive factors for failure after initial treatment were recurrence of ipsilateral pneumothorax, high degree of lung collapse, and radiological evidence of bullae. The predictive factor for recurrence after the last treatment was the previous episode of ipsilateral pneumothorax. Observation was superior to tube drainage in success rate to cease air leak and recurrence rate, although this effect was not statistically significant.