O2155: Risks for Recurrence After Primary Spontaneous Pneumothorax: Results from a Multicenter Study

Background: Management of pediatric primary spontaneous pneumothorax (PSP) is not standardized, and the risk of recurrence may vary based on initial treatment strategy. This study aimed to use a multicenter cohort of pediatric patients to explore practice variation in management of PSP and to examine risk factors for recurrence, including management strategy.

Methods: A multicenter retrospective review was conducted at five tertiary pediatric hospitals of patients (≤21 years) who presented with PSP over an eleven-year period (2011-2022). Initial management was defined as observation only, chest tube placement, or operation during the index admission. Size of PSP was measured as the maximal apical distance on x-ray. Chi-square, Fisher's exact, and Kruskal-Wallis tests were used to examine associations between patient characteristics at first PSP presentation and recurrence, defined as re-presentation of an ipsilateral PSP after discharge. Kaplan-Meier curves and multivariate Cox-regression then estimated the risk of PSP recurrence up to 5 years after primary hospitalization based on initial size and management strategy.

Results: Of the 282 patients with PSP, most were male (90.4%) and white (79.1%), with an average age of 15.5 years and mean BMI 19.1. Median initial PTX size was 4.5cm (range 0.2-16.8cm), and first management strategies were observation in 72 (25.5%) patients, chest tube placement in 113 (40.1%) patients, and operative management in 91(34.4%) patients. Operations included were resection alone (8.2%), pleurectomy and/or pleurodesis (40.2%), and both resection with pleural procedure (47.4%). Overall, 91 (32.3%) patients experienced ipsilateral recurrence. Median time to PSP recurrence was 80 days (range 1-2465), with 53.8% occurring within 3 months of initial presentation, and 80.2% occurring within 12 months. Recurrence rates were different depending on initial management strategy, with 23 (25.3%) patients recurring after observation only, 52 (57.1%) patients after chest tube placement, and 14 (15.4%) after operative management (p < 0.001; Figure 1). History of connective tissue disorder, active smoking history, or laterality were not associated with recurrence. Further, patients who recurred were more likely to develop future contralateral PSP (34.1% vs. 12.2%, p< 0.001). The risk of recurrence increased with initial PTX size (HR 1.08, 95% CI 1.01-1.17, p=0.045), although no significant PTX size threshold emerged. When compared to surgery, observation of initial PSP was associated with increased risk of recurrence (HR 3.42, 95% CI 1.54-7.61, p=0.003) as was tube thoracostomy only (HR 4.26, 95% CI 2.31-7.83, p< 0.001). In subgroup analysis of surgically managed patients, type of procedure performed (resection vs. pleurodesis vs. pleurectomy) was not associated with increased recurrence risk.

Conclusion: Increasing size of PSP is associated with increasing risk of recurrence within 5 years. Initial operative management was associated with reduced risk of recurrence. Further research is required to define an optimal threshold for operative management in this population.