A study published in the journal Thrombosis suggests that follow-up in patients with inferior vena cava filters can reduce patient morbidity. IVC filters are used to catch blood clots and stop them from becoming an embolism; an estimated 250,000 are implanted in Americans each year. The authors of the study point out that the filters can cause long-term complications if they are not removed at the appropriate time. “Insertion of an IVC filter can be a safe and effective way to avoid PE in thrombosis patients who cannot be anticoagulated. If temporary filters are not promptly removed they can become difficult to remove, causing avoidable complications and often requiring lifelong warfarin.”
IVC filters are implanted in the inferior vena cava to prevent blood clots from being lodged in the lungs, resulting in pulmonary embolism. Patients at risk for pulmonary embolism include those with venous thromboembolism and deep vein thrombosis. Typical treatment involves anticoagulants (bloodthinners), but sometimes IVC filters are used when these drugs are contraindicated.
According to the authors, it is best to remove filters within 14 days of implantation although in some cases it can be retrieved as late as 26 weeks later. Actual filter removal, however, does not always happen. The study authors cite research showing that IVC filters are only retrieved 20 to 40 percent of the time in eligible patients. Poor follow-up may be due to several factors, including poor documentation of retrieval plan and cancer diagnosis.
The authors emphasize that a follow-up plan is crucial in patients with removable IVC filters. “Patient factors or the clinical scenario may change meaning that filter removal is no longer safe or no longer desired. Unfortunately, even when prompt retrieval is indicated, many filters are not actually removed with most studies showing removal rates of between 20 and 40%”
The researchers tested a model for implementing a follow-up strategy in patients with retrievable IVC filters. The study looked at two sequential audits of patients with retrievable IVC filters examined over a 15-month period; one where the strategy was implemented and one where it was not. Compared to the group that did not implement the follow-up plan, the group in which the follow-up plan was implemented saw a reduction in the number of failed retrievals (15% to 9%). In this group, “100% of placed IVC filters were followed up appropriately. The proposed model is an easily implemented plan to avoid patient morbidity caused by temporary IVCfilters made unintentionally permanent by loss to follow-up.”