Risk factors of postoperative recurrence of primary spontaneous pneumothorax

Background: Spontaneous pneumothorax is common in relatively young, healthy patients. The risk factors for postoperative recurrence after correction are not fully understood. Methods: We retrospectively reviewed the records of patients who underwent surgery for spontaneous pneumothorax between January 2006 and October 2017. We assessed the possible factors causing postoperative recurrence using univariate and multivariate analyses. We then used the inverse probability of treatment-weighted method to correct for confounding factors. Results: Postoperative recurrence was observed in 41 of 233 patients (17.6%). A significant association with recurrence was noted for primary spontaneous pneumothorax (PSP), never smokers, thoracoscopic surgery, patients younger than 30 years, operative time less than 100 minutes, and surgery by a resident surgeon. Patients younger than 30 years of age had a 5-year recurrence-free probability of 46.3%. On multivariate analysis, patients younger than 30 years was an independent risk factor for recurrence. The confounding factors for recurrence of PSP included patients younger than 30 years, surgery by a resident surgeon, and thoracoscopic surgery. After adjusting for confounders, patients younger than 30 years was the only factor associated with recurrence (P=0.015). Patients who underwent bulla ligation with pleural reinforcement using an absorbable polyglycolic acid (PGA) sheet had a 4% recurrence rate and a 5-year recurrence-free probability of 90.0%. Conclusions: Patients younger than 30 years of age is a significant factor for postoperative recurrence in patients with PSP. Surgeons may attempt to prevent postoperative recurrence by devising the operative method and pleural reinforcement methods.