Inherent dangers of simultaneous application of microfibrillar collagen hemostat and blood-saving devices.

Microfibrillar collagen hemostat is a topically applicable hemostatic agent that has been introduced relatively recently. Because of the possibility that this substance may pass through different blood-collecting circuits and cause organ damage if reintroduced into the patient's circulation, we performed a series of in vitro and in vivo experiments. The results of these experiments suggest that such a passage may indeed occur and could cause organ damage, either by direct or by induced embolization that cannot be completely prevented even with the application of commercially used filters. We therefore recommend that the substance should not be used if the shed blood is intended to be collected and returned into the patient's circulation.