Prophylactic Inferior Vena Cava Filter Placement in Adult Spinal Reconstruction

INTRODUCTION: Combined anterior posterior spinal reconstruction carries a 6% incidence of pulmonary embolism. Anticoagulation for prophylaxis against deep venous thrombosis (DVT) carries a 5% incidence of major bleeds as well as a risk of epidural hematoma with irreversible neurologic compromise. Mechanoprophylaxis alone maybe insufficient protection in high risk patients. Heparinization for pulmonary embolus (PE) in postoperative spinal surgery patients is associated with a 67% complication rate. Prophylactic inferior venal caval (IVC) filter placement has been shown to be safe and efficacious in trauma patients. To date there has been little evaluation of this technique in spine surgery patients.

MATERIALS AND METHODS: In a prospective study, 22 patients (15M:7F, median age 51.5 years) undergoing major spinal reconstruction received prophylactic, pre-operative IVC filter placement. This high risk group by the following criteria: 1) contraindication to anticoagulation; 2) bedridden for long periods; 3) staged procedures; 4) abdominal vessel manipulation; and 5) history of hypercoagulability, thromboembolism, or malignancy. Patients were prospectively followed for complications related to the filter, rate of DVT formation, rate of PE. This was also compared to a retrospective review for PE at the same institution of a matched cohort.

RESULTS: At a mean follow-up of 15.2 months, no patients developed a PE, 2 had a DVT. 1 died from unrelated surgical complications. 1 patient (4.5% overall morbidity rate) developed bilateral DVT associated with filter insertion and required thrombolytic therapy. The matched cohort PE rate at the same institution was 12%. The literature rate for combined anterior-posterior surgery is 6%.

CONCLUSIONS: The morbidity rate for prophylactic IVC filter placement (4.5%) is less than that of prophylactic anticoagulation (5.7%) or therapeutic anticoagulation for PE (67%). Prophylactic IVC filter placement appears to substantially decrease the PE rate from 6-12% to zero, in this small series. In high risk patients, IVC filter placement appears to be a safe and efficacious intervention for prevention of PE.