LONG-TERM FOLLOW-UP OF THE GUNTHER BASKET INFERIOR VENA-CAVA FILTER -DOES MECHANICAL INSTABILITY CAUSE COMPLICATIONS

Purpose: The Gunther basket inferior vena cava filter (GBF) has been w ithdrawn from the market because of its mechanical instability, but a number of patients still live with the device. Methods: In a two-cente r study, we evaluated the long-term follow-up of the GBF, based on cli nical data in 78 patients, and on imaging studies including plain radi ographs, Doppler ultrasound, angiography, or computed tomography (CT) in 50 patients. Results: In a mean of period 3 years, pulmonary emboli sm was diagnosed in five patients (6.4%), with an overall rate of 0.02 embolic episodes per patient per year. None of these patients require d hospitalization, and there were no deaths due to pulmonary embolism. Inferior vena cava thrombosis was documented in three patients (3.9%) , and occulsive venous thrombosis at the access site in seven patients (9%). Spontaneous migration was documented in 43% of the examined fil ters and spontaneous disruption in 77%. Dislocated filter fragments we re localized by CT in the adjacent retroperitoneum in 11%, in the aort ic lumen in 2%, and in a peripheral pulmonary artery in 7%. None of th e patients had symptoms attributable to filter migration or disruption . Conclusion: Our results indicate that the rate of clinically relevan t complications with the GBF is no higher than with other vena cava fi lters. Because mechanical instability of the GBF had no clinical conse quences, we conclude that patients who live with this device may be ob served and treated in a manner similar to patients with other vena cav a filters.