New definition and natural history of patients with diffuse pulmonary arteriovenous malformations: Twenty-seven-year experience

Background: Patients with diffuse pulmonary arteriovenous malformations (PAVM), a small but important subset of the PAVM population, have significant morbidity and mortality rates. Methods: Thirty-six patients (21 female and 15 male) with diffuse PAVM from a cohort of 821 consecutive patients with PAVM were evaluated. Diffuse PAVM were categorized angiographically: involvement of one or more segmental pulmonary arteries in one or both lungs. Hereditary hemorrhagic telangiectasia (HHT) status, gender, presence or absence of large (≥ 3-mm diameter artery) focal PAVM, oxygen saturations, complications including hemoptysis, years of follow-up, and survival were tabulated. Results: HHT was present in 29 of 36 patients (81%), and diffuse PAVM were more commonly bilateral (26 of 36 patients, 72%) than unilateral (10 of 36 patients, 28%) [p = 0.02]. Female gender was associated with bilateral diffuse PAVM (19 of 26 patients, 73%) [p = 0.01]. Focal PAVM were present in both groups but more commonly in patients with bilateral involvement (16 of 26 patients, 62%) [p = 0.02]. Initial oxygen saturations (pulse oximetry, standing) of patients with unilateral and bilateral diffuse PAVM were 87 ± 7% and 79 ± 8% (mean ± SD), respectively (p = 0.02). The last or current values for patients with unilateral and bilateral involvement are 95 ± 3% and 85 ± 7%, respectively (p < 0.0001). Nine deaths occurred, and all were in patients with bilateral involvement. Deaths were due to hemoptysis of bronchial artery origin (n = 2), hemorrhage from duodenal ulcer (n = 1), spontaneous liver necrosis (n = 3), brain hemorrhage (n = 1), brain abscess (n = 1), and operative death during attempted lung transplant (n = 1). Conclusions: Patients with diffuse PAVM are a high-risk group, and yearly follow-up is recommended.