Idiopathic pulmonary arteriovenous malformations: clinical and imaging characteristics.

Pulmonary arteriovenous malformations (PAVMs) can cause stroke, brain abscess or life-threatening haemorrhage. Most PAVMs are associated with hereditary haemorrhagic telangiectasia (HHT). The aim of the present study was to describe the clinical presentation and treatment outcomes of those with idiopathic PAVMs, which has not previously been described in the literature. Patients with idiopathic PAVMs were identified at our HHT centre. Retrospective review of charts and imaging were performed. 20 patients were identified with idiopathic PAVMs. The most common symptoms reported were dyspnoea and migraines (50 and 30% of patients, respectively). Previous complications of PAVMs included haemoptysis (20%), stroke (20%) and brain abscess (5%). A total of 28 focal PAVMs were identified. Most patients (80%) had a solitary PAVM. 13 out of 28 PAVMs (46%) were located in the lower lobes. Most were simple and fistulous rather than complex and plexiform. Transcatheter embolotherapy was performed in 17 patients and was successful in improving oxygenation in all cases. The clinical manifestations and complications of idiopathic PAVMs are similar to those associated with HHT. Idiopathic PAVMs are anatomically similar to HHT-related PAVMs except for a greater number of solitary PAVMs and a lack of lower lobe predominance. Transcatheter embolotherapy is a safe and effective method for treating idiopathic PAVMs.