Ex Vivo Testing of Heparin-Coated Extracorporeal Circuits: Bovine Experiments
| Autor: | Patrick W. Weerwind, Theo Lindhout, F. H. Van Der Veen, D. S. De Jong, P. T. Cahalan |
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| Rok vydání: | 1998 |
| Předmět: |
medicine.diagnostic_test
biology Chemistry Biomedical Engineering Activated clotting time Medicine (miscellaneous) Thrombogenicity Bioengineering General Medicine Heparin 030204 cardiovascular system & hematology Fibrin Extracorporeal Biomaterials 03 medical and health sciences 0302 clinical medicine 030228 respiratory system medicine biology.protein Perfusion Oxygenator Ex vivo medicine.drug Biomedical engineering |
| Zdroj: | The International Journal of Artificial Organs. 21:291-298 |
| ISSN: | 1724-6040 0391-3988 |
| DOI: | 10.1177/039139889802100511 |
| Popis: | In this study the intrinsic thrombogenicity of the extracorporeal circuits and the benefit of heparin-bonded circuits in an extracorporeal life support system without full systemic heparinization and with minimal interference of the so called material-independent factors was tested in four calves. In two circuits (group A) all blood-contacting surfaces were coated with end-point-attached heparin and the other two were non-coated (group B). Under standardized conditions the calves were perfused at a blood flow rate of 2 L/min. After only one bolus injection of heparin (250 IU/kg body weight) before cannulation, plasma heparin activity rapidly decreased in both groups: half life of about 55 minutes. This decrease of the heparin activity was accompanied by a fall of the activated clotting time (ACT) level to baseline values. The experiments using a heparin-coated circuit, had a runtime of more than 360 minutes, whereas the experiments using a non-coated circuit had to be terminated after a runtime of 255 minutes, because massive fibrin formation was noticed in the circuit. This formation was accompanied by a rapid increase in the line pressure, measured just before the inlet of the oxygenator. The macroscopic inspections after terminating the experiments and rinsing the circuit showed a clean circuit in group A. The fibrinopeptide A (FPA) level increased faster during perfusion with the non-coated circuit than in the heparin coated circuit. Lung histopathological examinations of the lungs of the animals in group A showed no fibrin deposition, whereas most of the blood vessels of the lung preparations of the animals in group B were partially or completely occluded with fibrin. These results suggest that heparin-bonding greatly reduces the thrombogenicity of the extracorporeal circuit, and therefore it can reduce the need for systemic heparinization in an extracorporeal life support system. |
| Databáze: | OpenAIRE |
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