nvestigation of The Safety and Effectiveness of Peri-Procedural Prophylactic Antithrombotic Therapy with Fixed-Dose Intravenous Heparin In Peripheral Vascular Interventions

Introduction: Fixed-dose unfractionated heparin prior to arterial crossclamping has historic use in patients undergoing vascular interventions. Routine intra-operative monitoring of heparin during vascular interventions is not routinely performed. There is no clear consensus on heparin reversal following vascular interventions. Aims: Primary endpoint was the efectiveness of fxed-dose heparin, in patients undergoing elective vascular interventions, measured using activated clotting time (ACT). Secondary endpoints were the rates of thrombotic events, haemorrhagic events, need for re-operation, and blood transfusion. Methods: This is a prospective cohort study, from 20192021, where 73-patients undergoing elective vascular interventions were recruited from the vascular service at University Hospital Galway. Participants were administered a fxed-dose of intravenous heparin prior to crossclamping, then objectively assessed for thrombotic and haemorrhagic events, intra-operatively and for 30-days post-operatively. Results: The mean dose of unfractionated heparin administered was 4800 IU. The mean target ACT at three, thirty, sixty-minutes and skin closure were 168, 163, 148 and 159-s respectively. One thrombotic event was recorded, with a limb occlusion complicating endovascular repair of an abdominal aortic aneurysm (EVAR). One haemorrhagic event occurred, with a haematoma post-carotid endarterectomy. No signifcant blood loss occurred. One patient required packed red cell transfusion for haemoglobin drop post-operatively. Re-interventions included thrombin injection of a pseudoaneurysm, neck haematoma evacuation and a femoro-femoral crossover for occluded EVAR limb. Conclusion: Fixed-dose heparin is associated with both thrombotic and haemorrhagic complications. There is need for a dosing protocol for heparin, heparin reversal and intraoperative ACT monitoring to minimise the risk of these complications