Summary
As a potent anticoagulant agent, fondaparinux exposes a risk of bleeding. An effective
way to reverse its effects is needed. It was the objective to study efficacy and safety
of prothrombin complex concentrate (PCC) to reverse the anticoagulant effect of fondaparinux
in a rabbit model of bleeding and thrombosis. In anaesthetised and ventilated rabbits,
the Folts model was applied: a stenosis (75%) and an injury were carried out on the
carotid artery, inducing thrombosis. Blood flow decreased as thrombus size increased
until the pressure gradient was such that the thrombus was released and local blood
flow was suddenly restored. This is known as a cyclic flow reduction (CFR). After
the first CFR, rabbits were randomised into three groups: control (saline and saline
after 1 minute), fondaparinux (fondaparinux [3 mg.kg−1] and saline), PCC (fondaparinux and PCC [40 UI.kg−1]). Then CFRs were recorded over 20 minutes. The following were measured: ear immersion
bleeding time (BT), haemoglobin blood level (Hb1) and thrombelasto-metric parameters
(ROTEM®). Finally, a hepatosplenic section was performed; 15 minutes later, the amount of
blood loss was recorded as primary endpoint and Hb2 was measured. Blood loss was increased
with fondaparinux and normalised with PCC. Regarding ROTEM® INTEM, fondaparinux increased clotting time and clotting formation time. PCC normalised
these parameters. EXTEM and FIBTEM tests were not modified. Regarding safety, PCC
did not increase CFRs. PCC reduced bleeding without increasing thrombosis and was
effective to reverse the haemorrhagic effect of fondaparinux in this rabbit model.
Keywords
Arterial thrombosis - coagulation factors - haemostasis - animal models - coagulation
inhibitors