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.
TWO of the following:
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)
- 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
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
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.
- Tortuous vessels precluding angiographic access
- Pre exisiting coagulopathy
- Established infarct on imaging
- Contrast allergy
In essence, a stroke patient presents well within the timeframe for reperfusion therapy.
Let us tabulate this answer.
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.
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.
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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.