• Endovascular surgery requires the patient to be anticoagulated perioperatively

• Heparin administration should be guided by POC Haemacron ACT monitoring

• This guideline aims to optimise and standardise perioperative heparin administration during endovascular surgery.

This is a controlled document. If you are using a printed copy, check it against the guidelines site to ensure you are using the latest edition. Print copies must be destroyed after use.

Abbreviations

Endovascular surgery involves the deployment of a stent graft into the aorta, usually via the iliac vessels. This can be a simple infra renal graft or a complex graft involving branches or fenestrations. This procedure is carried out by inserting guide wires either via arteriotomy or increasingly as a percutaneous procedure.

During the time the wires are within the vessel, there is disturbance in normal blood flow and an increased pro thrombotic risk. As a result, these patients require anticoagulation. The protocol for heparin dosing was developed in 2016 after review of data obtained following a standard 5000 units administration. This protocol based the administration on a units/kg regime monitored by near patient testing of ACT (activated clotting time). This protocol has been revised based on our data obtained from Epic and the National Vascular Registry.

This guideline has been agreed with the FHFT vascular surgeons and the department of Anaesthesia after presentation of audit data in November 2024.

The clinicians should be trained to use the POC Haemacron.

Target ACT after heparin administration should be >250

1. A baseline ACT should be taken after insertion of an arterial line (there must be no delay between the blood leaving the patient and being injected onto the cuvette so allow the machine to warm up before taking the first sample)

2. At the time of wire insertions as directed by the surgeon heparin should be given as a bolus dose of 70-80 units/kg

3. Check the ACT at 10 minutes post heparin administration

4. If ACT is not >250 consider administration of a further heparin dose1000-2000 units

5. Check the ACT hourly

6. Consider additional bolus doses of 1000-2000 units if the ACT drops below 250 and the procedure is not close to conclusion

1. A baseline ACT should be taken after insertion of an arterial line

2. At the time of wire insertion as directed by the surgeon, heparin should be given as a bolus dose of 70-80 units/kg

3. Check the ACT at 10 minutes post heparin administration

4. If the ACT is not >250 consider administration of a further 1000 -2000 units

5. Commence an infusion of heparin at 1000 units/ hr

6. Check the ACT hourly

7. If the ACT is below 250 during the infusion, consider giving a bolus of 1000-2000 units and increase the infusion to 1500 units/hr

8. Heparin administration should be discontinued following discussion with the surgeon once the stent and fenestrations have been fully deployed

Compliance with guideline

All ACT data is collected and reviewed.

Registrars' prize [presentation]. VASGBI Annual Scientific Meeting, Durham. 11 September 2018.

Menzies, A. and Gudgeon, J. (2024) Activated clotting time guided heparinization in endovascular abdominal aortic aneurysm repair: a review of compliance and effectiveness of Trust guidelines [poster presentation]. VASGBI Annual Scientific Meeting, Leeds. 9-10 May. Available at: https://vasgbi.com/media/1734/activated-clotting-time-guided-heparinization-in-endovascular-abdominal-aortic-aneurysm-repair-a-review-of-compliance-and-effectiveness-of-trust-guidelines.pdf (Accessed: 04 March 2025).

Cooper, M.A. and Upchurch, G.R. Jr. (2019) 'The Society of Vascular Surgery Practice Guidelines on the Care of Patients With Abdominal Aortic Aneurysms', JAMA Surgery, 154(6), pp. 553-554. Available at: https://doi.org/10.1001/jamasurg.2019.0566

Wanhainen, A. et al. (2024) 'Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms', European Journal of Vascular and Endovascular Surgery, 67(2), pp. 192-331. Available at: https://doi.org/10.1016/j.ejvs.2023.11.002

Kasapis, C. et al. (2010) 'Defining the optimal degree of heparin anticoagulation for peripheral vascular interventions: insight from a large, regional, multicenter registry', Circulation: Cardiac Interventions, 3(6), pp. 593-601. Available at: https://doi.org/10.1161/circinterventions.110.957381

Thorne, R. (2018) 'The introduction and development of a protocol for heparin dosing for endovascular surgery based on ACT monitoring', Annual scientific meeting: abstracts for the Durham meeting. Durham, 10-11 September. Vascular Anaesthesia Society of Great Britain and Ireland, pp. 47. Available at: https://vasgbi.com/media/1136/abstract-booklet-durham-2018.pdf (Accessed: 15 January 2024).

This guideline has been registered with the Trust. However, clinical guidelines are guidelines only. The interpretation and application of clinical guidelines will remain the responsibility of the individual clinician. If in doubt, contact a senior colleague or expert. Caution is advised when using guidelines after the review date.

This guideline is for use in Frimley Health NHS Foundation Trust hospitals only. Any use outside this location will not be supported by the Trust and will be at the risk of the individual using it.

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