Pulmonary vasculitis in Behçet’s disease: Reference atlas computed tomography pulmonary angiography (CTPA) findings and risk assessment-management proposal

Background and aim: Pulmonary artery aneurysms (PAAs) are the most well-defined type of pulmonary vascular complication in Behçet’s disease (BD). The aim of this study is to analyze which CT pulmonary angiography (CTPA) signs are associated with serious morbidity and mortality. Methods: The study included 42 BD patients with pulmonary vascular complications. All patients’ medical records were reviewed retrospectively in terms of demographics, disease characteristics, laboratory investigations, pulmonary manifestations, arterial and/or venous thrombosis and CTPA vascular and parenchymal findings. Results: Deep venous thrombosis was observed in 31 (73.8%) patients, arterial thrombosis in 13 (31%), peripheral arterial aneurysms in 12 (28.5%), haemoptysis in 38 (90.5%), and fatal haemoptysis in 8 (19 %) patients. CTPA revealed: in situ thrombosis in 14(33.3%) patients, true stable PAAs in 13 (31), true unstable PAAs in 11 (26.2%), stable pulmonary artery pseudoaneurysms (PAPs) in 7 (16.7%), unstable PAPs in 17 (40.5%), perianeurysmal leaking in 26 (61.9%) and bronchial indentation in 19(45.2%). In regression analysis, fatal outcomes were associated with age in years (p=0.035), arterial thrombosis (p=0.025), peripheral arterial aneurysms (p=0.010), intracardiac thrombosis (p=0.026) and positively associated with haemoptysis severity (p<0.001). The severity of hemoptysis affects the likelihood of death over time (p=0.0057), whereas combined immunomodulator therapy reduces the risk of death over time (P= 0.0680). Conclusion: Peripheral arterial thrombosis and/or aneurysms, intracardiac thrombosis and haemoptysis severity are predictors of fatal outcomes in BD pulmonary vasculitis. PAPs with perianeurysmal alveolar haemorrhage and/or bronchial indentation are serious CTPA signs that require prompt identification and aggressive treatment. PAPs are a more serious aneurysmal pattern than true PAAs because they are a contained rupture of a PA branch in the context of pulmonary vasculitis.