Abstract No. 671 The effect of inferior vena cava size on filter complications: one size does not fit all

Abstract

To determine the effect of inferior vena cava (IVC) size on development of complications as determined on post placement CT scan, including filter tilt, penetration, and thrombosis. Patients that underwent IVC filter placement between March 2015-December 2017 were included in the study. Coronal and sagittal CT scan images before placement of the filter were used to measure the medio-lateral (ML) and antero-posterior (AP) diameters of the IVC, 2 cm below the right renal vein. Two- dimensional (2D) axial IVC size at this level was then calculated using the ML and AP diameters. CT scan images after placement of the filter were reviewed for any complications, including filter tilt, penetration and thrombosis. IVC filter ML diameter, AP diameter and 2D axial sizes were then compared between patients with and without complications in CT scan. A total of 86 patients (female = 59%, male = 41%, age: 67 ± 14.1 years) were enrolled. The CT scan before placement of filter was available at 2.2 ± 5.2 months. The complications noted in the post filter placement CT scan (interval = 5.4 ± 6.75 months) were tilt in 32(37%) patients, penetration in 4(4.7%) and thrombosis in 8(9.3%) patients. Patients with tilt had significantly larger 2D axial IVC size compared to patients without tilt. Almost significant association was also noted in terms of ML diameter; however, no significant difference was noted in terms of AP diameter. There is significant association between the two-dimensional (2D) size of the IVC and future complications such as tilt noted on post placement CT scan. Two-dimensional evaluations of the IVC could provide clinicians better insight regarding the anatomy of the IVC, particularly considering the variability of the IVC size with hydration status and respiration. Future large sample studies should further define the filter specific thresholds.Tabled 1IVC AP diameter (mm)IVC ML diameter (mm)No tilt (n=54)15.9 ± 4.819.3 ± 2.9992.7 ± 400.7Tilt (n=32)17.7 ± 4.820.8 ± 3.61184.7 ± 452.8P value0.110.050.04 Open table in a new tab