Optional filters in trauma patients: can retrieval rates be improved?

Prophylactic inferior vena cava interruption may be appropriate in trauma patients at risk for pulmonary embolism for whom anticoagulation is contraindicated. The Recovery filter is approved for removal up to 180 days from insertion. High retrieval rates need to be achieved before we can lower the threshold for inserting these filters prophylactically. The objective of this study was to evaluate the retrieval rate of the Recovery filter in this patient population and how it has influenced our practice. This is a retrospective study in which the records of 122 consecutive trauma patients in whom the Recovery filters were inserted between October 2003 and October 2005 were reviewed. Patients who had the new generation of this filter were excluded. All these filters were inserted with the intention of retrieval. We attempted to contact all these patients at 3 months. The technical factors associated with failure to retrieve these filters were reviewed. There were no complications related to filter insertion. Excluding six patients (4.9%) who expired from causes unrelated to the insertion procedure, 20 patients could not be reached (17.3%) and 21 patients declined retrieval (18.1%). The filters were considered permanent in 18 patients (15.5%) if they were not ambulatory or if they developed inferior vena cava occlusion. Inferior vena cava occlusion was diagnosed in four patients (5.5%). Seventy-three (62.9%) patients presented for follow-up and were evaluated by color venous duplex ultrasound. We attempted to retrieve the filters in 52 patients and were successful in 45 (86.5%). However, the total retrieval rate was 40.5%. All failures of retrieval were related to tilting of the filters or bending of the limbs. There were no complications related to the retrieval procedure. Insertion and retrieval of the Recovery inferior vena cava filter are safe. In spite of the thorough follow-up and the good success rate in retrieving the filters, the overall retrieval rate in this patient population is still low. This should be strongly considered at the time of insertion. Multiple factors were found to contribute. Attention to details in patient selection and follow-up as well as modifications in technique may improve the retrieval rate.