Before being used in humans, medical devices need, in general, to have some testing performed in order to assess their safety profile. This biocompatibility assessment includes various endpoints, among which a certain number are focused on the potential effect on blood - also known as hemocompatibility.
Even within the cardiovascular field, the type of blood contact may vary from non-contact, indirect, external communicating with direct contact, or for implanted devices. Official guideline documents such as ISO 10993-4, provide direction for deciding whether testing for interaction with blood is necessary. Complex phenomenon such as the hemostasis can be best monitored in-vivo, with the device used the way it is intended. When testing is performed in-vitro, an appropriate model or system should be used that simulates closely enough the clinical situation, so that these pre-clinical results possess enough predictive value. The appropriate choice of controls, as well a clear identification of the test article, (or the part(s) thereof), is also critical as part of a proper strategy to allow smooth regulatory review such as 510K or CE mark.
Both in-vitro and in-vivo models can be used for this purpose, each being set up with the goal of mimicking clinical application and allowing assessment of the proper end-point.
Whether the blood contact is direct or indirect, each device needs to be considered for their hemocompatibility, such as hemolysis, thrombosis, platelet activation, hematology and complement activation.
This webinar will present various aspects of hemocompatibility testing: selection of tests, identification of what devices need to be tested and what part of the device needs testing. It will also cover some technical details about how the various tests function: chemically and mechanically induced hemolysis, pro-coagulant effect, effect on platelets and leukocytes, and activation of the complement.
Devices that are involved in the circulation of blood, like cardiopulmonary bypass systems or apheresis equipment, may compromise hemocompatibility, damaging the red blood cells by mechanical means. Other devices may manifest some hemolytic potential via their chemical composition, either as extractable or leachable, or by direct contact of the red blood cells with the device.
As foreign materials, medical devices can activate the coagulation cascade. The resulting thrombus, either on the surface of the devices or dislodged, may be the source of serious complications. Some membranes used in hemodialysis have been linked to complement activation, leading to pulmonary distress and coagulation disorders.
A proper selection of the most applicable tests is therefore essential to detect and predict any deleterious interaction between the devices and the blood.