# Utilization Practices of Inferior Vena Cava Filters at an Academic Medical Center

## TL;DR

This study examines how IVC filters are used in a medical center, finding many are placed without standard indications and few are removed promptly.

## Contribution

The study provides insights into non-standard IVC filter usage and retrieval rates in a tertiary academic medical center.

## Key findings

- 35% of IVC filters were placed for nonstandard indications.
- Only 46% of eligible patients had their filters removed within a median of five months.
- 14.5% of patients who had filters removed experienced re-thrombosis.

## Abstract

Introduction: Anticoagulation is the mainstay of management for patients with venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE). Inferior vena cava (IVC) filters are indicated in select patients who are not candidates for anticoagulation. There is a lack of quality evidence supporting other indications. In addition, long-term benefits and safety profiles of IVC filters have not been established. We investigated the utilization practice of IVC filters in a contemporary series of patients in a tertiary academic medical center.

Methodology: A retrospective review of 200 patients who received IVC filters at Virginia Commonwealth University (VCU) Medical Center in the years 2017 and 2018 was conducted. Adult patients 18 years of age or older with or without cancer were included, and patients were selected consecutively until data on 200 patients were collected. Data on patient demographics, an indication of IVC filter placement, filter retrieval rate, and re-thrombosis events over a median follow-up period of nine months were extracted from the electronic medical record and analyzed.

Results: A total of 200 patients (105 male and 95 female) were included with a median age of 61 years (range 17-92 years). Of the 200 patients, 97 (48.5%) had a DVT, 28 (14%) had a PE, 73 (36.5%) had both a PE and DVT, and 2 (1%) had thrombosis at other sites. A total of 130 (65%) patients had an IVC filter placed because of a contraindication to anticoagulation, while 70 (35%) had an IVC filter placed for other nonstandard indications, which included new or worsening VTE despite anticoagulation, recent VTE who must have anticoagulation held during surgery, primary prevention in high-risk patients, and extensive disease burden among other reasons. Seventy-two (36%) patients had active malignancy at the time of filter placement, and 64 (32%) were lost to follow-up. Of the 119 patients who were potentially eligible for filter retrieval, 55 (46%) patients had their IVC filters removed at a median of five months after insertion. Of the 55 patients who had IVC filters removed, 8 (14.5%) patients experienced a re-thrombosis event within a median follow-up of 39 months. Of the 145 patients who still had their filter in place at the time of death or last follow-up, 5 (3.4%) patients experienced a re-thrombosis event within a median follow-up of three months.

Conclusions: One-third of the patients in this series had an IVC filter placed without a standard indication, and less than half of them had the IVC filters removed within one year of placement. Additionally, one-third of the patients were lost to follow-up, highlighting the need for improved structured follow-up programs and education among both patients and providers regarding the indications for placement and retrieval to minimize complications.