The clinical features, image findings and risk factors of vena cava syndrome in Behçet's syndrome

OBJECTIVESTo investigate the clinical features, image findings, and potential risk factors of vena cava syndrome (VCS) in Behçet's syndrome (BS). METHODSWe conducted a case-control study in our BS registry database from 2012 to 2021. Fifty-five BS patients with VCS were enrolled in the case group, and two BS patients without VCS were selected as controls for each VCS case using risk-set-sampling. Multivariable logistic regression was used to detect the risk factors of VCS, and the outcome of these patients was also analysed. We also conducted an exploratory study to evaluate spectral computed tomography (CT) imaging in detecting thrombosis in BS patients with inferior VCS (IVCS). RESULTSMultivariable logistic regression analysis revealed male gender (OR 11.16, 95%CI 3.34-37.32), early-onset BS (60 mm/hr (OR 3.83, 95%CI 1.02-12.23) and pathergy reaction (OR 5.10, 95%CI 2.11-12.32) as potential risk factors of VCS in BS patients. For 4 BS patients with IVCS due to thrombosis, spectral CT found better contrast between IVC and thrombi at a low energy level of 40keV using virtual monoenergetic imaging than conventional images at 120kV. With a median follow-up of 3.3 years, the respective estimated 1- and 5-year survival rates were 96.3% and 94.2%, and respective estimated 1- and 5-year relapse-free rates were 93.9% and 78.0%. CONCLUSIONSMale, early-onset BS, ESR >60 mm/hr, and pathergy reaction are potential risk factors of VCS in BS patients. Spectral CT is valuable in detecting thrombus in vena cava.