Abstract
Despite increasing use of vena cava filters (VCFs) for pulmonary embolism (PE) prophylaxis after major trauma, there is continued debate regarding their safety and efficacy. We aimed to evaluate the impact of prophylactic VCFs on the incidence of PE after major trauma and to describe VCF related complications.
Prospectively collected data from The Alfred Hospital Trauma Registry were used to identify all major trauma patients admitted between 1 July 2001 and 1 July 2008. Data for each patient was collated from the registry. This included patient demographics, injury specific data, management details (including prophylactic VCF use) and clinical outcomes (including the occurrence of PE). Medical record and radiology chart review was used to verify all PEs. Potential PE risk factors were assessed as covariates in a univariate analysis, with PE as the dependent variable. A multivariate analysis was then performed using multiple logistic regression adjusting for baseline imbalances and known covariates.
During this period, 6,344 major trauma patients were treated, with 73.2% male, mean age of 44.2 +/− 21.0 SD, 90.2% with a blunt mechanism of injury and mean ISS of 24.3 +/− 12.0 SD. Of these patients, 511 (8.1%) received prophylactic VCFs, (inserted in absence of PE) at the discretion of the treating clinician. There were 45 PE (incidence of 0.71%), of which two were fatal. Three variables were independently associated with the occurrence of PE in the multivariate analysis: (i) presence of prophylactic VCF (OR 0.28; 95%CI 0.09 - 0.89); (ii) number of injuries to the AIS body region lower limb (OR 1.31; 95%CI 1.17 - 1.47) and (iii) central venous catheterisation (OR 1.87; 95%CI 1.88 - 6.17). Data was available on the VCF database for 429 of the 511 patients with VCFs (84.0%). The mean time to prophylactic VCF insertion was 3.6 +/− 0.2 SEM days after admission. The VCF major complication rate was 2.6% (n=11), including four non-fatal PE. The technical success rate for retrieval was 92.4% (279 retrievals from 302 attempts) and the overall retrieval rate was 65.0% (279 retrievals from 429 placements).
Prophylactic VCFs are associated with a reduced rate of PE when used in selected major trauma patients. In addition, prophylactic VCFs have a low major complication rate and high rate of technical success for retrieval.
