Natural History of Contralateral Bullae/Blebs After Ipsilateral Video-Assisted Thoracoscopic Surgery for Primary Spontaneous Pneumothorax: A Retrospective Cohort Study

Abstract

Background: Contralateral bullae/blebs are frequently found in patients who are scheduled to undergo ipsilateral video-assisted thoracoscopic surgery (VATS) for primary spontaneous pneumothorax (PSP).

Research question: Should visible contralateral bullae/blebs be simultaneously resected when ipsilateral VATS bullectomy is performed?

Study design and methods: In this single-center, retrospective cohort study, we included patients aged ≤ 30 years who underwent ipsilateral VATS for PSP from April 2009 to December 2019. Electronic medical records, radiograph images, and preoperative high-resolution CT images were reviewed. The primary end point was recurrence-free survival (no contralateral pneumothorax) after discharge of ipsilateral VATS for PSP, determined via Kaplan-Meier analysis. Recurrence was compared between the group with and that without contralateral bullae/blebs by using the log-rank test. A multivariable Cox proportional hazards model was constructed to investigate risk factors for contralateral pneumothorax.

Results: Among 567 patients, contralateral pneumothorax occurred in 86 of them after ipsilateral VATS (15.2%) during a median follow-up period of 51.3 (interquartile range, 67.2) months. The 1-, 5-, and 10-year recurrence-free survival rates were 92.2%, 83.7%, and 79.9%, respectively. Contralateral recurrence was higher in the group with (82/455, 18.0%) than in that without (4/112, 3.6%) contralateral bullae/blebs (P < .001). Age (hazard ratio [HR], 0.701; 95% CI, 0.629-0.780; P < .001), current smoking (HR, 2.106; 95% CI, 1.158-3.831; P = .015), and the presence of bullae/blebs (increasing with size, HR, 4.818-8.980; all P < .05) were independent risk factors for contralateral pneumothorax. The annual rates of contralateral pneumothorax in the group with (4.0%) and in that without (0.7%) contralateral bullae/blebs declined over time.

Interpretation: Although contralateral bullae/blebs were common in patients who underwent ipsilateral VATS for PSP and were statistically significantly associated with future pneumothorax, the annual rate of pneumothorax was 4.0% in such patients, and it decreased over time. Therefore, a conservative approach on unruptured contralateral bullae/blebs is recommended.

Keywords: blebs; bullae; contralateral recurrence; spontaneous pneumothorax; video-assisted thoracoscopic surgery.