Blood biocompatibility assessment of an intravenous gas exchange device

To treat acute lung failure, an intravenous membrane gas exchange device, the Hattler Catheter, is currently under development. Several methods were employed to evaluate the biocompatibility of the device during preclinical testing in bovines, and potential coatings for the fibers comprising the device were screened for their effectiveness in reducing thrombus deposition in vitro. Flow cytometric analysis demonstrated that the device had the capacity to activate platelets as evidenced by significant increases in circulating platelet microaggregates and activated platelets. Thrombus was observed on 20 +/- 6% of the surface area of devices implanted for up to 53 h. Adding aspirin to the antithrombotic therapy permitted two devices to remain implanted up to 96 h with reduced platelet activation and only 3% of the surface covered with thrombus. The application of heparin-based coatings significantly reduced thrombus deposition in vitro. The results suggest that with the use of appropriate antithrombotic therapies and surface coatings the Hattler Catheter might successfully provide support for acute lung failure without thrombotic complications.