The RETRIEVE trial: safety and effectiveness of the retrievable crux vena cava filter.

Purpose: To evaluate the safety and effectiveness of the Crux vena cava filter in patients at risk for pulmonary embolism (PE).

Materials And Methods: The Crux Biomedical Evaluation of the Crux Inferior Vena Cava Filter System trial was an international prospective, multicenter, single-arm clinical trial in 125 patients implanted with the Crux filter between June 2010 and June 2011. Follow-up was 180 days after filter placement and 30 days after filter retrieval. The primary objective was to determine whether the clinical success rate was at least 80%. Clinical success was defined as technical success of deployment and freedom from definite PE, filter migration, and device-related adverse events requiring intervention.

Results: The clinical success rate was 96.0% (120 of 125), with a one-sided lower limit of the 95% confidence interval of 91.8%. The rate of technical success was 98.4% (123 of 125). There were three cases of definite PE (2.4%), two cases of deployment failure, and no cases of device migration, embolization, fracture, or tilting. Investigators observed nine cases of thrombus (all nonocclusive) in or near the filter (six during retrieval evaluation vena cavography, two during computed tomography [CT] scans for PE symptoms, and one during CT for cancer management) and 13 cases of deep vein thrombosis. Device retrieval was attempted at a mean of 84.6 days±57.6 (range, 6-190 d) after implantation and was successful for 98.1% of patients (53 of 54). All deaths (n = 14) were determined to be unrelated to the filter or PE.

Conclusions: The Crux vena cava filter performed safely, with high rates of clinical, technical, and retrieval success.