Excimer laser-assisted retrieval of Günther Tulip vena cava filters: a pilot study in a canine Model.

ABSTRACT

PURPOSE: Although most Günther Tulip filters (GTFs) can be safely retrieved within a few months after implantation, their recommended safe retrieval period is within a few weeks. This study aims to assess the feasibility of excimer laser-assisted retrieval of GTFs incorporated into the inferior vena cava (IVC) wall in a canine model. MATERIALS AND METHODS: Six GTFs were implanted in six mongrel dogs and retrieved after four weeks. The retrieval system consisted of a 14-F excimer laser sheath, an 8-F guide catheter, and a 15-mm Goose Neck snare. RESULTS: All filters were tightly fixed to the IVC wall. After ablation of the adhesions by excimer laser emission, all filters were successfully retrieved. Final cavography after retrieval revealed no caval damage except for minor extravasation in three dogs. Examination of the caval specimen taken from a dog immediately after filter retrieval revealed partial absence of the intima and media. In the remaining five dogs, cavography performed 2 days after filter retrieval revealed complete hemostasis and almost indistinguishable intimal indentations. On follow-up cavography 28 days after filter retrieval, caval stenosis with 38% +/- 11% diameter narrowing was noted. The caval specimen obtained from a dog at 28 days showed neointima formation at the level where the filter struts were in contact with the caval wall. The other four dogs have survived for more than 3 months without any adverse events. CONCLUSIONS: Laser-assisted retrieval of a GTF incorporated into the IVC wall is feasible in dogs.