The Gunther Tulip (Cook) filter was used in 112 patients. Median follow-up was 60 months (range 6–120). Indications for use of a filter included: (i) in patients with established venous thromboembolism and a contra-indication or complications to anticoagulation (n=105, 94%) or (ii) in patients considered high-risk for venous thromboembolism despite adequate anticoagulation (n=7, 6%).
The majority of filters (n=109, 97%) were placed in the infrarenal vena cava. Tilting of the filter at the time of insertion was the most common complication (n=7). In 45 (40%) patients, filters were inserted for peri-operative cover and would all have been suitable for removal post-operatively. Filters were only retrieved in six (13%) of these patients at a median time of 19 (7–42) days after insertion.
Recommendations were published by the American College of Chest Physicians and the British Committee for Standards in Haematology regarding indications, contraindications and use of concomitant anticoagulants with inferior vena cava filters. These suggest the use of inferior vena cava filters when anticoagulation is not possible.
Patients with acute deep vein thrombosis or pulmonary embolism with inferior vena cava filters are recommended to receive a conventional course or anticoagulant therapy as soon as the risk of bleeding resolves.
No guidelines are available for the follow-up of inferior vena cava filters to monitor complications and the recommended times of filter retrieval. The recommendations for uncommon but critical groups of patients e.g. the pregnant patients who may need inferior vena cava filters are still weak.
The report concluded there were no long-term follow-up plans to monitor patients who still had filters in situ. Closer follow-up of patients is required to determine if removal should be mandatory. Although broad guidelines are available these need to be expanded.
