Paradoxical Embolization in Untreated Recurrent Pulmonary Arteriovenous Malformations: Incidence and Risk Factors

This study estimated the incidence of paradoxical embolization (PDE) in patients with untreated pulmonary arteriovenous malformation (PAVM) recurrence after embolotherapy and explored potential lesion- and patient-level associations. Fifteen patients with 25 recurrent PAVMs were identified; all lesions remained untreated for ≥1 year, often in the setting of fragmented care. More than 65.1 patient-years of follow-up, 6 patients (40%; 95% CI, 16%-68%) experienced PDE, corresponding to an annualized rate of 9.2 events per 100 patient-years (95% CI, 3.4-20.0). Lesions in patients with PDE were larger, and recurrence burden was greater, although differences were not statistically significant. Follow-up intervals were heterogeneous, and among patients without events, median follow-up from recurrence was 48.7 months. These findings suggest a persistent risk of PDE in untreated recurrent PAVMs and support ongoing surveillance and consideration of reintervention while underscoring the need for larger studies.