Does a gender have something to do with clinical pictures of primary spontaneous pneumothorax?

Primary spontaneous pneumothorax is relatively rarer in women than in men. In addition, women develop secondary spontaneous pneumothorax, such as lymphangioleiomyomatosis, which is rare and difficult to diagnose. Therefore, the clinical characteristics of primary spontaneous pneumothorax in women remain unknown presently. We compared the clinical characteristics of primary spontaneous pneumothorax between the two sexes at two pneumothorax centers. Between January 2015 and July 2019, we retrospectively evaluated 627 cases (106 women and 521 men) who underwent first video-assisted thoracoscopic surgery for primary spontaneous pneumothorax and extracted the medical backgrounds and postoperative recurrence between the sexes. Univariate and multivariate analysis was used to examine the effect of sexual specificity on postoperative recurrence. Among women and men with PSP, the mean ages were 27.8 ± 10.7 and 24.3 ± 10.0 years, respectively; their mean heights were 162.0 ± 5.9 and 173.3 ± 6.1 cm, respectively. These differences were statistically significant. Three women (2.8%) and 54 men (10.4%) developed postoperative recurrence, which showed significant difference on Kaplan-Meier analysis (p = 0.027). Univariate and multivariate analysis showed the factors; women (p = 0.045, hazard ratio: 0.289 [95% confidence interval 0.086-0.973]) and smoker (p = 0.035, hazard ratio: 0.269 [95% confidence interval 0.079-0.909]) had the preventing factor for postoperative recurrence, respectively. Women with PSP had lower postoperative recurrence rate than men. Although we could not reveal why women had lower postoperative recurrence rates than men in this study, the sexual difference such as hormonal cycle, development of body structure possibly affects the clinical characteristics of women with primary spontaneous pneumothorax.