Abstract
BACKGROUND: Investigating the association between common iliac vein (CIV) compression and inferior vena cava (IVC) thrombosis could have important clinical implications, such as a potential reduction in the use of IVC filters in low-risk patients and guidance for decision-making in thrombosis management. This study aimed to clarify the impact of the CIV compression degree on the incidence of IVC thrombosis in patients with lower extremity deep vein thrombosis (DVT). METHODS: This single-center, retrospective study was performed between January 2015 and July 2023. A total of 391 eligible patients (mean age 60.42±16.67 years; 53.96% male) were included. The quantitative evaluation included the minimum diameter of the CIV, and the compression percentage was calculated on computed tomography venography. Univariable analysis and subsequent multivariable analysis, as well as propensity score matching (PSM), were used to analyze odds ratios (ORs) with 95% confidence intervals (CIs). The association between IVC thrombosis and CIV compression on a continuous scale was evaluated via restricted cubic splines (RCSs). RESULTS: Iliofemoral DVT and a larger minimum diameter were associated with an increased risk of IVC thrombosis, whereas older age and a higher compression percentage were linked to a decreased risk. After adjustments for age, male sex, hypertension, and iliofemoral DVT via PSM, the statistically significant associations of CIV minimum diameter (adjusted OR =1.10, 95% CI: 1.02-1.18; P<0.01) with compression percentage (adjusted OR =0.99, 95% CI: 0.98-0.99; P<0.01) and IVC thrombosis remained. A reduced risk of IVC thrombosis was significantly associated with moderate compression (OR =0.36; 95% CI: 0.17-0.78; P=0.01) and severe compression (OR =0.14; 95% CI: 0.05-0.42; P<0.01). The RCS analysis revealed that a smaller minimum diameter or greater compression percentage was associated with a continuously decreasing IVC thrombosis risk when the minimum diameter was <5.04 mm or compression was >49.81%. CONCLUSIONS: Compared with no or mild compression, moderate and severe CIV compression was associated with a reduced risk of IVC thrombosis. A higher CIV compression degree was consistently associated with a decreased IVC thrombosis risk when the minimum diameter was <5.04 mm or when the compression was >49.81%.