Supplemental Use of Inferior Vena Cava Filters: A Review of An Institutional Experience.

Introduction: Increasing use of inferior vena cava (IVC) filters in recent years as a preventative measure against pulmonary embolism (PE) has raised concern for usage outside of accepted guidelines. Based on the American College of Chest Physicians 2004 guidelines for the initial treatment of deep vein thrombosis (DVT) and PE, and the Eastern Association for the Surgery of Trauma 2002 guidelines for prophylaxis of PE, placement of an IVC filter is indicated in patients who either have, or are at high risk for thromboembolism, but have a contraindication for anticoagulation, a complication of anticoagulant treatment, or recurrent thromboembolism despite adequate anticoagulation. The purpose of our study is to identify patients who meet the guidelines for IVC filter placement and to compare clinical outcomes with those who did not meet the guidelines.

Methods: Charts of 558 patients who received IVC filter placement were reviewed from Jan 1, 2004 to Dec 31, 2007. Patients were divided into two groups called within-guidelines or supplemental. The within-guidelines group included patients that met the criteria described above. The supplemental indication group included patients who did not have a contraindication or failure of anticoagulation. Patient characteristics and clinical outcomes between the two groups were compared and analyzed.

Results: The within-guidelines group had 362 patients and the supplemental group had 196 patients. While there were more males in the within-guidelines group, age, race, length of stay, and in-hospital mortality were comparable between the two groups. Clinical follow-up in patients with a supplemental indication showed 1 (0.5%) case of post-filter PE, 2 (1%) cases of IVC thrombosis, 7 (3.6%) cases of DVT. Patients who were in the within-guidelines indication group had 4 (1.1%) cases of post-filter PE, 13 (3.6%) cases of IVC thrombosis, and 34 (9.4%) cases of DVT. All patients who developed post-filter PE had a prior DVT at the time of filter placement, and the risk of developing post-filter IVC thrombosis and PE is higher in patients with prior thromboembolic disease. Conversely, patients who did not have a VTE event before filter placement were at a significantly lower risk of developing IVC thrombosis and PE.

Conclusion: Anticoagulation should be initiated at the earliest possible time in patients treated with an IVC filter to prevent subsequent venous thromboembolic disease. Our data does not support the use of IVC filter in patients who can tolerate anticoagulation and have no prior venous thromboembolic event due to the low risk of developing pulmonary embolism