Relationship between vascular access and angulation of vena cava filter at placement and retrieval: a multicenter retrospective cohort study

Background: Inferior vena cava (IVC) filters are commonly used intravascular devices designed to prevent fatal pulmonary embolism (PE), maintaining the IVC filter as centered as possible is fundamental for achieving its filtration function. Objective: This study aimed to characterize the tilt angles of IVC filter between the vascular access of internal jugular vein (IJV) and femoral vein (FV), as well as to identify factors associated with increased or decreased tilt angles between placement and retrieval. Design: This is a multicenter retrospective study. Methods: A multicenter retrospective study was conducted from October 2017 to March 2019. The primary outcome was the change in filter tilt between placement and retrieval. The secondary outcome was the identifications of factors associated with increased or decreased tilt angle. Relevant variables were analyzed using t-tests, Chi-square tests, Fisher's exact tests, while multivariate logistic regression analysis was used to determine risk factors. Results: A total of 184 eligible patients were included in this study. The IJV group had a lower likelihood of tilt angle over 10 degrees at the time of placement compared to the FVs group (0% versus 12.5%, p = 0.040). Among the 171 patients with a mean dwell time of 22.1 days, the IJV group had a higher likelihood of tilt angle over 10 degrees than the FVs group (10.3% versus 2.3%, p = 0.080). The use of FVs access at placement was associated with a higher difference between placement and retrieval filter tilt angles (p < 0.01). Multivariate logistic regression analysis showed that hypertension [odds ratio (OR) 0.668; 95% confidence interval (CI) 0.328-1.358, p = 0.265], cardiologic artery disease (OR 0.537; 95% CI 0.136-2.130, p = 0.377), cerebral venous disease (OR 0.555; 95% CI 0.186-1.651, p = 0.290), filter types (OR 1.624; 95% CI 0.851-3.096, p = 0.141), and IVC filter thrombosis (OR 1.634; 95% CI 0.804-3.323, p = 0.175) were not associated with increased filter tilt angle. Right side (OR 0.434; 95% CI 0.202-0.930, p = 0.032) or bilateral lower extremity deep vein thrombosis (LEDVT) (OR 0.383; 95% CI 0.148-0.995, p = 0.049) were identified as protective factors. Conclusion: IJV access was associated with a lower filter tilt angle at the time of placement, while FVs access was linked to a higher difference between placement and retrieval tilt angles. Right side or bilateral LEDVT were identified as protective factors against increased IVC filter tilt angle.