A 60-year-old male presents 2 hours after the onset of vertigo and loss of consciousness. CT brain is performed and shows right basilar and vertebral occlusion with no evidence of infarction.

Discuss two possible definitive treatment strategies for this condition, including the indications and contra-indications of each.

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College Answer

TWO of the following:

Intravenous thrombolysis

The patient is within the suggested time window for thrombolysis and by current guidelines should receive intravenous rtPA. Overall this treatment reduces deaths and dependency but is associated with a risk of potentially fatal intracranial haemorrhage.

Indications include patients with acute ischaemic stroke presenting within the appropriate time window (note to examiners – while initial guidelines suggested a time window of three hours there is data suggesting use up to 4.5 hours may be beneficial)

Contraindications include:

  • Stroke or head trauma in previous 3 months
  • Intracranial haemorrhage: past or present
  • Major surgery in previous 14 days
  • GI or urinary tract bleeding in previous 21 days
  • MI in previous 3 months
  • Non-compressible arterial puncture in previous 7 days
  • Persistent severe hypertension
  • Active bleeding or acute trauma
  • Thrombocytopaenia

Intra-arterial thrombolysis

Although intra-arterial thrombolysis results in higher rates of re-cannulation there is no evidence that it reduces mortality or morbidity. However in patients who have undergone recent surgery (and therefore have a contra-indication to intravenous thrombolysis) or exceed the 6 hour time window for intravenous thrombolysis intra-arterial thrombolysis may be useful

Endovascular Thrombectomy

This technique may be used in large vessel thrombus,especially if recanalisation has not occurred with intravenous thrombolysis, or the patient is outside the time window . It requires specialist expertise that may not be generally available, and carries the risk of vascular damage or dissection with potential worsening of symptoms.

Indications would include ischaemic stroke in a large vessel in patients who have either failed thrombolysis or have a contraindication to it.

Contraindications include:

  • Tortuous vessels precluding angiographic access
  • Pre exisiting coagulopathy
  • Established infarct on imaging
  • Contrast allergy

Discussion

In essence, a stroke patient presents well within the timeframe for reperfusion therapy.

Let us tabulate this answer.

Management Options for an Early Presentation of Ischaemic Stroke
Strategy Indications Contraindications
Intravenous Thrombolysis
  • Presentation within 4.5 (ideally, 3) hours
  • Age over 18 and less than 80
  • History of head trauma in the last 3 months
  • History of stroke in the previous 3 months
  • Arterial puncture in a non-compressible site in the past 7 days
  • Platelet count less than 100
  • Any heparin within 48 hours of the stroke
  • Current anticoagulant therapy
  • Hypoglycaemia
  • Multilobar infarction (more than one-third of a cerebral hemisphere) on CT scan
Intraarterial thrombolysis
  • Contraindication to systemic thrombolysis
  • Systemic thrombolysis  is considered likely to fail
  • Systemic thrombolysis has failed (after 1 hr)
  • A large vessel occlusion is present
  • Poor vascular access
  • Intracerebral haemorrhage
  • Cerebral malignancy (relative)
Endovascular embolectomy
  • Presentation within 8 hours
  • Contraindication to systemic thrombolysis (or failure to respond to it)
  • Clot is in a large vessel
  • Contraindications to carotid or verterbal arterial access (eg. significant carotid atherosclerosis)
  • Peripheral vascular disease (i.e. difficult access)
  • Uncontrolled coagulopathy
  • Obvious and well-established infact on CT or MRI (thus, no point in embolectomy)
  • Contrast allergy

The window for thrombolysis seems to be three hours according to the college answer, though  "there is data suggesting use up to 4.5 hours may be beneficial". That probably refers to  Hacke et al (ECLASS III, 2008) who went as late as 4.5 hours post stroke. Modern Australian Stroke Foundation guidelines recommend 4.5 hours as the cut-off on the basis of the meta-analysis articles by Wardlaw et al (2014) and Emerson et al (2014). The MERCI trial investigators managed to get good outcomes even 8 hours post infarct, which is encouraging. However, these outcomes were still poorer than historical controls. 

The issue of acute stroke management is discussed in brief summary elsewhere.

References

References

Oh's Intensive Care manual: Chapter   51   (pp. 568)  Acute  cerebrovascular  complications by Bernard  Riley  and  Thearina  de  Beer.

Smith, Wade S., et al. "Safety and efficacy of mechanical embolectomy in acute ischemic stroke results of the MERCI trial." Stroke 36.7 (2005): 1432-1438.

Nogueira, R. G., et al. "Endovascular approaches to acute stroke, part 2: a comprehensive review of studies and trials." American Journal of Neuroradiology30.5 (2009): 859-875.

Brinjikji, Waleed, et al. "Patient outcomes with endovascular embolectomy therapy for acute ischemic stroke a study of the national inpatient sample: 2006 to 2008." Stroke 42.6 (2011): 1648-1652.

Kidwell, Chelsea S., et al. "Design and rationale of the mechanical retrieval and recanalization of stroke clots using embolectomy (mr rescue) trial."International Journal of Stroke 9.1 (2014): 110-116.

Jansen, Olav, et al. "Neurothrombectomy for the treatment of acute ischemic stroke: results from the TREVO study." Cerebrovascular Diseases 36.3 (2013): 218-225.

Furlan, Anthony, et al. "Intra-arterial prourokinase for acute ischemic stroke: the PROACT II study: a randomized controlled trial." Jama 282.21 (1999): 2003-2011.

Sacks, David, et al. "Multisociety consensus quality improvement guidelines for intraarterial catheter‐directed treatment of acute ischemic stroke, from the American Society of Neuroradiology, Canadian Interventional Radiology Association, Cardiovascular and Interventional Radiological Society of Europe, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of NeuroInterventional Surgery, European Society of Minimally Invasive Neurological Therapy, and Society of Vascular and ...." Catheterization and Cardiovascular Interventions 82.2 (2013): E52-E68.

Ogawa, Akira, et al. "Randomized trial of intraarterial infusion of urokinase within 6 hours of middle cerebral artery stroke The Middle Cerebral Artery Embolism Local Fibrinolytic Intervention Trial (MELT) Japan." Stroke 38.10 (2007): 2633-2639.

Hacke, Werner, et al. "Thrombolysis with alteplase 3 to 4.5 hours after acute ischemic stroke." New England Journal of Medicine 359.13 (2008): 1317-1329.

Wardlaw, Joanna M., et al. "Thrombolysis for acute ischaemic stroke." The Cochrane database of systematic reviews 7 (2014): CD000213.

Emberson, Jonathan, et al. "Effect of treatment delay, age, and stroke severity on the effects of intravenous thrombolysis with alteplase for acute ischaemic stroke: a meta-analysis of individual patient data from randomised trials." The Lancet384.9958 (2014): 1929-1935.