Rate of thrombus accumulation on intravenacaval IVOX devices explanted from human clinical trial patients with acute respiratory failure.

The weight gain of IVOX devices removed from the first 49 human clinical trials patients after from 1 to 29 days of implantation into the venae caval blood stream has been assessed. Each patient had received sufficient systemic heparin to maintain activated clotting times between 150 and 200 s while the IVOX device was indwelling. The nature of the material accumulating on the IVOX device was documented histologically as being thrombus in various stages of development. The weight gain findings indicate that an average of 2.0 g of thrombus accumulates per 24 h on IVOX devices indwelling in the venous blood stream of moderately anticoagulated human acute respiratory failure patients. The rate of weight gain per 24 h of the IVOX device was more rapid during the first 96 h after its implantation than during its second, third, or fourth week of implantation. The accumulated thrombus on the IVOX hollow fibers was associated with a small but measurable decrease (approximately 1%/day) in gas transfer efficiency of the implanted device. The data support the conclusion that IVOX can function effectively and safely without major thrombus formation for up to 29 days in moderately anticoagulated human acute respiratory failure patients.