Predictors and Prevention of Recurrence After Secondary Spontaneous Pneumothorax: A Systematic Review.

Secondary spontaneous pneumothorax (SSP) carries a clinically important risk of recurrence, but the available evidence is dispersed across heterogeneous disease-specific and treatment cohorts. This systematic review aimed to identify clinical, radiological, physiological, disease-related, clinical-course, and treatment-related determinants of recurrence after SSP. PubMed/MEDLINE was searched on 19 July 2026 without a date restriction. Adult and adult-inclusive SSP cohorts were eligible, as were mixed spontaneous-pneumothorax cohorts containing patients with SSP when a recurrence determinant was evaluated. Evidence without SSP-specific estimates was classified as indirect. Of 77 records screened, 50 reports were sought, 31 were retrieved and assessed, two were excluded at full text, and 29 studies were included. Nineteen reports could not be retrieved and were classified as unavailable rather than scientifically excluded. Because of substantial heterogeneity in populations, interventions, recurrence definitions, follow-up periods, and effect measures, a narrative synthesis was undertaken without meta-analysis. Recurrence was associated with severe emphysematous or fibrotic lung damage, non-chronic obstructive pulmonary disease (non-COPD) aetiology, prolonged air leak, impaired forced expiratory volume in one second (FEV1), Birt-Hogg-Dubé syndrome, chest deformity in Marfan syndrome, and selected malignancy-related radiographic features. Definitive recurrence prophylaxis, video-assisted thoracoscopic surgery (VATS)-based procedures, pleural interventions, and medical pleurodesis were generally associated with lower recurrence than drainage alone. Technical comparisons suggested that the effectiveness of lesion control and pleural intervention may be more important than the number of thoracoscopic ports. Evidence favouring thoracotomy over VATS arose from mixed cohorts and should be interpreted cautiously. SSP recurrence risk should therefore be assessed using the underlying disease, structural lung damage, physiological reserve, behaviour of the index episode, and suitability for definitive pleural intervention.