3:45 PM Abstract No. 278 Prevalence and characterization of the interaction of inferior vena cava filters with the spine in patients undergoing complex filter removal

Abstract

To examine types and prevalence of interaction of inferior vena cava (IVC) filters with the spine in patients presenting for complex filter removal. The records of 447 patients presenting for complex removal of IVC filters were reviewed. Patient demographics, IVC filter dwell time, filter fracture status, and CT evidence of filter interaction with the spine were collected. Spinal interaction was defined as a filter strut touching or penetrating into the vertebral body or disk. Patients with evidence of filter penetration and spinal interaction had the abdominal CT that preceded filter removal assessed by two interventional radiologists to further categorize the type of spinal interaction, including bony reaction and osteophyte formation. Statistical analysis was performed including Chi-square and Fisher’s exact test. 80/447 patients (18%) had evidence of spinal interaction by the filter on abdominal CT (table ). The mean size of bony reaction observed was 11.4 mm. Interaction with the spine was more common in single point of fixation filters than those with rails (P = 0.047) and was more likely in round wire filters than flat wire ones (P = 0.001). Patients with interaction had longer dwell times (mean, 5.7 years; SD, 4.46 years) compared with those without interaction (mean, 3.2 years; SD, 3.85 years); this relationship was significant (P <0.0001). Females were more likely than males to experience filter/spine interaction, with an odds ratio (OR) of 1.71 (P = 0.04). If a filter displayed spinal interaction, it was more likely to be fractured with an OR of 2.24 (P = 0.001). 39% of patients with symptoms had filter interaction, compared to 14% of those without symptoms (OR: 3.99). These symptoms included chest and back pain. IVC filters may penetrate the IVC wall and interact with the spine. Such interaction may be symptomatic and associated with filter fracture.Tabled 1Characterization of Spine–Filter InteractionType of Interactionn (% of patients with interaction)Bony reaction58 (73) Lytic reaction14 (18) Sclerotic reaction24 (30) Lytic and sclerotic reaction20 (25)Osteophyte formation39 (49)Leg penetration into bone34 (43) Open table in a new tab