Retrievable inferior vena cava filters in geriatric trauma: Is there an age bias?

Background: Trauma patients are at increased risk for developing venous thromboembolic (VTE) disease. The EAST (Eastern Association for the Surgery of Trauma) practice management guidelines identified risk factors for VTE, as well as indications for prophylactic inferior vena cava filters (IVCF). In a 2009 study, our institution found a 26% retrieval rate for IVCF. Lack of retrieval was most consistently due to lack of follow-up. Our study is a follow-up analysis for retrieval rate of IVCF, since the formation of a geriatric trauma service. We anticipated that geriatric trauma patients would have a lower rate of IVCF retrieval compared to the general trauma patient.

Methods: Our study population consisted of trauma patients admitted from January 2008 to August 2013, with documented VTE or high risk for VTE with contraindication to anticoagulation.

Inclusion Criteria: IVCF placed in trauma patients.

Exclusion Criteria: permanent filters, retrievable filters placed permanently, non-trauma patients, superior vena cava filters and patients who died before discharge.

Results: During the study period, 160 trauma patients had an IVCF placed, of which 147 survived and were discharged. Of those patients, 66% (97/147) were planned for retrieval. Overall, the retrieval rate was 34% (33/97). Following age categorization, rates were 47% (30/64) and 9% (3/33) for those <65 and >/=65 years old, respectively. Applying Fisher's Exact Test to a crosstab of planned retrieval by age category yielded a statistically significant difference, p<0.0005 at alpha=0.05. In the geriatric population with IVCFs not retrieved, 23% (7/30) died and 67% (20/30) were lost to follow-up.

Conclusion: IVCF plays a critical role in the management of trauma patients with VTE, particularly the geriatric population. Since our 2009 study, we have improved nearly ten percentage points (26% to 34%); however, we exposed an age bias with retrieval rate being lower in patients >/=65 compared to those <65 (9% vs. 47%).