Why optional inferior vena cava filters are not always retrieved? A real world 19 years experience in a Swiss tertiary care university hospital.

Background: inferior vena cava filters (IVCF) are widely used to prevent thromboembolic events in patients not suitable for anticoagulation (AC). Although new generations of filters are optional and therefore retrievable, most of them become permanent. Aim of our study was to evaluate real life IVCF management in a tertiary hospital including retrieval rates and reasons for permanent filtering.

Materials And Methods: Electronic charts from patients receiving IVCF in a Swiss university hospital, during 1999-2017, were retrospectively identified. Patients were classified in two groups, according to filter retrieval (RG) or not (NRG). Type and reasons of filter placement were assessed. Retrieval, complications, and mortality rates were calculated. Reasons of non-retrieval were analyzed.

Results: 920 patients received an IVCF during 1999-2017. Filters were retrieved in 372 patients (40.65%). Subjects in the NRG were significantly older, more chronically ill, and presented higher mortality rate at 12 months following filter insertion (29.60% vs. 4.30%; p < 0.001). Reasons for non-retrieval included lack of follow-up (22.34%), persistent contraindications to AC (20.51%), technical issues (17.40%), and severe morbidity with short life expectancy (17.22%). Overall, complication rates after filter placement was 18.58%. Most reported complication was filter thrombosis (15.60%).

Conclusions: In a real life setting, optional IVCF are still too often left in place indefinitely. Need for a systematic follow-up to ensure prompt filter retrieval is warranted. IVCF are not retrieved mostly in chronically and more severely ill patients, likely accounting for higher mortality in these subjects.