Retrieval of Gunther tulip optional vena cava filters 30 days after implantation:: A prospective clinical study

PURPOSE: To report on the feasibility and safety of retrieval of the Gunther Tulip optional vena cava filter 30 days after initial implantation. MATERIALS AND METHODS: From March 2004 to September 2005, a single-center prospective study was undertaken in 35 patients who required inferior vena cava (IVC) filtration. All the Gunther Tulip filters (GTFs) were implanted with the intention to be removed 30 days after initial implantation. A modified commercial dynamometer was used to measure the force required to remove the device. The degree of difficulty to remove the GTF was classified into four levels: N (no difficulty, force of 0-4.41 N), M (medium difficulty, force of 4.41-5.88 N), G (great difficulty, force of 5.88-9.8 N), and U (unable to remove). Clinical follow-up was performed 1, 3, 6, and 12 months after filter retrieval by review of medical records and imaging. RESULTS: Two of the 35 patients experienced extensive thrombosis in the IVC as revealed by abdominal computed tomography, and their filters were left in place on a permanent basis. One patient died of respiratory and cardiac failure during follow-up within the first 30 days after GTF insertion. Filter retrieval was attempted in the remaining 32 patients, and 31 of these attempts were successful (98%). The force necessary to disengage the GTF from the caval wall was less than 9.8 N (N, 79%; M, 13%; G, 6%). Attempts to remove the GTF failed in only one patient (2%). On follow-up times ranging between 14 and 640 days'(mean, 342.5 d), no complications or cases of recurrent pulmonary embolism were observed in this patient population. CONCLUSION: The Gunther Tulip optional IVC filter can be safely placed and retrieved percutaneously 30 days after initial implantation.