Prophylactic inferior vena cava (IVC) filter placement may increase the relative risk of deep venous thrombosis after acute spinal cord injury.

BACKGROUND: To determine whether the prophylactic placement of an inferior vena cava (IVC) filter after acute spinal cord injury (SCI) causes an increased incidence of deep venous thrombosis (DVT).

METHODS: A retrospective chart review was conducted employing charts from patients admitted to the SCI service of one inpatient rehabilitation center for 2 consecutive years. One hundred fourteen subjects met inclusion criteria, namely an acute SCI, length of rehabilitation stay greater than 7 days, and level of injury between C3 and L3. Subjects were classified into two groups: those who received a prophylactic IVC filter during their acute stay and those that did not. The occurrence of DVT during initial rehabilitation was the primary outcome measure. Other demographic and medical information including the occurrence of pulmonary embolism were also collected.

RESULTS: Of the 114 subjects, two were excluded because of DVT occurring before rehabilitation admission. Of the remainder, 54 (47%) had prophylactic IVC filters placed. Of those with filters, 11 (20.4%) experienced a DVT during their rehabilitation stay. Of the 58 without filters, only three (5.2%) experienced a DVT during rehabilitation (p = 0.021, Fisher's exact test). Confounding factors included the Injury Severity Score and possibly the cause of injury and presence of long bone fracture. Only one individual experienced pulmonary embolism during rehabilitation hospitalization, and that was in a person with a prophylactic IVC filter.

CONCLUSIONS: The presence of prophylactic IVC filters in acute SCI patients may actually increase the risk of DVT, which has its own associated morbidities and costs.