ACT (s)
Indications
High (300–350)
Procedures involving deep arterial injury, e.g., percutaneous transluminal angioplasty with/without stenting
Procedures with significant stasis of blood flow e.g., balloon occlusion of parent vessels
Moderate (250–300)
Procedures in which above mentioned thrombogenic elements are absent, e.g., embolization of an aneurysm, coiling of ruptured aneurysm, arteriovenous malformations
Consider short-term postoperative anticoagulation after endovascular intervention. According to our weight-based protocol, the patient is administered 900 IU if the weight is <70 kg and 1300 IU for >70 kg for 12 h following intervention.
Heparin Dosing for Post-Coiling Neurosurgery Patients
Suggested protocol: Weight 75 kg or less—900 units/h, no bolus doses, for 12 h.
Weight above 75 kg—1300 units/h, no bolus doses, for 12 h.
Labs: no ACT or other laboratory draws required.
Alternative: The most commonly used heparin weight-based protocol uses bolus dose of 80 u/kg/h followed by a maintenance IV infusion rate of 18 units/kg/hour.
Infusion rate 900–1300 units/h
Pt weight | Dose in units/kg/h |
|---|---|
50 kg | 18 |
60 kg | 15 |
70 kg | 13 |
75 kg | 12 |
80 kg | 16 |
90 kg | 14 |
100 kg | 13 |
110 kg | 12 |
120 kg or higher | 11 |
Major Complications
Hemorrhage.
Conversion of ischemic stroke to hemorrhagic stroke.
Heparin-induced thrombocytopenia (HIT): a potential life-threatening complication seen in up to 5–30% of patients exposed to unfractionated heparin. Due to the potential of significant HIT-induced thromboembolic complications, clinical, and laboratory surveillance of those receiving high-dose or long-term heparin (1 week or greater) is recommended.
Contraindications
Some practitioners consider systemic heparinization during endovascular intervention for an acutely ruptured aneurysm or AVM a contraindication. A majority do not. In case of an acutely ruptured aneurysm, we have found heparinization to be safe, when initiated after placement of the first coil. In unruptured aneurysms, heparinization may be initiated as soon as arterial access is secured.
Severe thrombocytopenia.
Heparin-induced thrombocytopenia.
An uncontrolled active bleeding site.
Reversal
Heparin is reversed by intravenous administration of protamine sulfate at 1 mg per 100 units of circulating heparin (not to exceed 50 mg total).
A preloaded syringe of 50 mg should remain available at all times during most endovascular procedures, to enable rapid bolus administration in case of an emergency.
While normally protamine is administered as an IV infusion over 10–30 min to prevent idiosyncratic hypotension and anaphylactoid symptoms, in case of endovascular emergencies (e.g., vessel perforation or intracranial aneurysm perforation), anticoagulation must be immediately reversed by rapid IV bolus of protamine (10 mg over 1–3 min).
Abciximab (ReoPro ® )
Mechanism
Antibodies that prevent binding of fibrinogen to platelet GP IIb/IIIa receptors.
Indications and Case Selection
Acute management of endoarterial thrombus associated with a neurointerventional device.
Acute arterial occlusion complicating a procedure.
Dissection with thrombus adherent to an intimal flap.
Prophylaxis for extracranial or intracranial stent implantation for atherosclerosis.
Dose
Loading Dose: 0.25 mg/kg followed by continuous IV infusion of 0.125 µg/kg/min (max 10 µg/min) for 12 h, then d/c.
Side Effects
Major bleeding: Older patients and those with lower body weight may be at increased risk. To minimize this risk, use lower doses, local trans-catheter rather than systemic infusions, shorter courses of the drug and avoid concomitant heparin therapy.
Thrombocytopenia.
Pseudo-thrombocytopenia.
Utricaria, diarrhea, and elevated serum amino-transferase levels.
Major Complications
Major bleeding.
Hemorrhagic conversion of infarct.
Contraindications
Active internal bleeding.
Recent (within 6 weeks) gastrointestinal (GI) or genitourinary (GU) bleeding of clinical significance.
History of cerebrovascular accident (CVA) within 2 years, or CVA with a significant residual neurological deficit.
Bleeding diathesis.
Thrombocytopenia (<100,000 cells/μL).
Recent (within 6 weeks) major surgery or trauma.
Severe uncontrolled hypertension.
Presumed or documented history of vasculitis.
Reversal
Discontinue drug infusion.
Allow 10–30 min for clearance of the drug from plasma, then
Administer Platelets transfusion.
Surgical intervention should be delayed for 12–24 h after discontinuation of abciximab infusion.
Aspirin (ASA)
Mechanism
A cyclo-oxygenase inhibitor that prevents formation of prostaglandins from arachidonic acid.
Indications and Case Selection
Prophylaxis of intra- (short-term) and post-procedural (short+ and long-term) thromboembolic events during endovascular procedures, e.g.,
diagnostic cerebral angiography,
coil embolization of aneurysms,
stent implantation (typically with a second antiplatelet agent),
balloon test occlusions,
therapeutic occlusion of large arteries.
Occasionally administered in conjunction with a second antiplatelet agent.
Subacute management of procedural complications, e.g.,
parent artery coil herniations,
thrombus or clot on coil phenomena,
in-stent thrombus (alone or in combination with a second agent).
Dose
325–1300 mg orally, daily.
Uncoated ASA achieves peak plasma concentrations within 30–40 min.
Enteric-coated ASA achieves peak plasma concentrations in up to 6 h.
60% of the population is resistant to the antiplatelet effect of low-dose (81 mg) ASA.
30% of the population is resistant to the antiplatelet effect of 325 mg/day regimen.
Side Effects
GI erosions.
Renal Insufficiency.
Headaches.
High-dose (unlike low-dose) regimens impede BP management by interacting with agents such as angiotensin-converting enzyme (ACE) inhibitors, or furosemide.
Unpredictability of individual response (ASA resistance).
Major Complications
Major bleeding including of GI system.
Contraindications
Uncontrolled hypertension.
Reversal
Reversal may be achieved by platelet transfusion.
Clopidogrel (Plavix™)
Mechanism
Platelet ADP receptor antagonist.
Indications and Case Selection
Prevention of intraprocedural and short-term post-procedural (4–12 weeks) thromboembolic events related to endovascular procedures. These include:
Coil embolization of wide-neck cerebral aneurysms where stent will be used.
Stent implantation (with a second antiplatelet agent).
Therapeutic occlusion of large arteries (often with a second antiplatelet agent).
Subacute management of procedural complications (alone or in combination with a second agent), e.g.,
Parent artery coil herniations.
Thrombus or clot on coil phenomena.
In-stent thrombus (may be more effective than other agents).
Dose
75 mg PO daily, start 5 days prior to the actual procedure because there is a 3- to 7-day latency period to full therapeutic effect.
LD: 300 mg PO, if there was no time to achieve therapeutic effect over a course of days. A therapeutic effect can usually be achieved within 2–3 h of LD.
Side Effects
Bone marrow suppression (less risk than Ticlid™; perform CBC blood test every 2 weeks for the first 3 months).
Neutropenia (risk similar to ASA at 0.2–0.5%).
TTP.
GI events: abdominal pain, dyspepsia, gastritis, diarrhea, constipation rash and other skin disorders.
Major Complications
Major bleeding.
Contraindications
Hypersensitivity to the drug.
Active bleeding.
Reversal
Platelet transfusion.
Ticlopidine
Mechanism
Platelet ADP receptor antagonist
Indications and Case Selection
As an alternative, in case of ASA intolerance or failure. Slightly more effective than ASA, but it has a more concerning side effect profile.
Dose
500 mg PO daily.
Side Effects
Bone marrow suppression. Requires a CBC blood test every 2 weeks for the first 3 months.
Aplastic anemia.
Severe neutropenia (absolute neutrophil count below 450/mm3).
Major hemorrhage.
Bone marrow related complications do not appear to be common when ticlopidine is used for periods shorter than 1 month.
Major Complications
Major bleeding.
Bone marrow suppression.
Severe Neutropenia.
TTP.
Contraindications
Hypersensitivity to the drug.
Active bleeding.
Reversal
Platelet transfusion along with methylprednisolone 20 mg IV.
Tissue Plasminogen Activator (TPA)
Mechanism
Converts plasminogen to plasmin, fibrin specific.
Indications and Case Selection
Patients with acute ischemic stroke who are:
18 years of age, or older.
Clinical diagnosis of ischemic stroke with measurable neurologic deficit.
Symptom onset less than 3 h (or less than 4.5 h in some cases) prior to initiation of treatment.
Symptom onset >3 h but less than 6 h in case of intra-arterial administration. This time window may be increased up to 24 h for posterior circulation (which has less likelihood of hemorrhagic conversion of infarct).
Exclusion criteria apply (see contraindications).
Dose
Intravenous: 0.9 mg/kg (max. 90 mg). The first 10% of the calculated dose is given as an IV bolus over 1 min, and the remainder is infused over an hour for patients within the 3- to 4.5-h window.Related posts:
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