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Stroke: Endovascular management of ischaemic stroke – radiology video tutorial

Stroke: Endovascular management of ischaemic stroke – radiology video tutorial


Hi, I am Peter Mitchell from Radiopaedia.org
and in this last episode of our stroke series we will be discussing endovascular intervention
on ischaemic stroke. The role of endovascular therapy for thromboembolic stroke continues
to evolve rapidly and remains controversial with little consensus on inclusion criteria
and outcome benefits. Various strategies have been tried over the years which can be divided
broadly into: intra-arterial thrombolysis, mechanical clot disruption, and clot retrieval Up to the mid 1990s, management of thromoboembolic
strokes was purely supportive, aimed at minimizing secondary injury resulting from swelling,
stroke extension and haemorrhagic transformation. Early work with intravenous thrombolysis was
encouraging and as early as 1990 administering concentrated thrombolyic agents (urokinase
/ streptokinase / tPA) via catheter directly into the occluded vessel or into the clot
was employed. This was often accompanied by mechanical clot disruption using catheter,
wire manipulation or later inflation of a small angioplasty balloon within the clot.
There were anecdotally effective but did not result in any appreciable outcome improvement
in trials. In 2001 the first clot retrieval device (Concentric
retriever) was approved by the FDA. The MERCI device was a small cork-screw like device
which was introduced into the clot and the clot pulled back into a guiding catheter.
Moderate success was achieved with this device, however recanalisation rates remained low. In 2012 a new type of device became available,
Solitaire, which comprised of a relatively open mesh stent, attached
to a wire hence retrievable, originally designed for use in treating intracranial aneurysms. Lets now have a look at a fairly typical case. This 60 year old male patient presented to
our emergency department with a right sided hemiplegia which had a sudden onset only 2
hours earlier. The initial non-contrast CT demonstrates no evidence of haemorrhage, but
a hyperdense left MCA, confirmed on CTA as an M1 segment occlusion. There
is no convincing grey matter hypoattenuation, an important negative as loss of grey white
matter differentiation suggest an established infarct. CT perfusion demonstrated prolonged mean transfer
time but no significant abnormality in cerebral blood volume. This is consistent with a large
ischemic penumbra. In other words most of the area supplied by the now occluded vessel
has not yet died, being supplied by collaterals, but is at risk of infarction if the vessel
is not opened. The patient was taken to the angiography suite
and a left common carotid injection confirmed complete occlusion of the cervical supraclinoid
ICA with only external carotid flow present. Note, only a small amount of contrast pools
in the carotid at the base of skull. At this point a guiding catheter was passed
through the occluded left ICA and with the aid of a wire the M1 clot traversed by the
solitaire device. The wire was removed and the outer catheter withdrawn deploying the
device. A few minutes are allowed to pass during which
time some blood can already pass through the clot and re-perfuse the brain distal to the
occlusion. This is sometimes referred to as ‘giving the brain a drink’. Once the device is well incorporated into
the clot, it is pulled back along, hopefully, with the clot. Here we can see the clot stuck
on the device, and angiographic images of the internal carotid demonstrate complete
recanalisation. Suction is applied to the balloon tipped guiding catheter in the internal
carotid artery, increasing the chance of successful clot withdrawal, and minimising the chances
of distal embolus. Prior to finishing the procedure a stent was
placed across the critical proximal ICA stenosis. A follow-up CT three days later demonstrates
an excellent outcome with no appreciable established infarction. The key to successful recanalisation, while
avoiding the complication of haemorrhagic transformation is good patient selection.
Although inclusion criteria vary from hospital to hospital and trial to trial, generally
a patient should have a clearly determined time of stroke onset within 4.5 hours of the
start of treatment. A non-contrast CT should demonstrate little established infarction.
Additionally, if available, CT perfusion demonstrating a small infarct core and a large penumbra
is ideal as this minimises the volume of tissue at risk of haemorrhage while maximizing the
amount of salvageable tissue. In carefully selected patients successful
clot retrieval can be achieved in up to 80% and in these patients, at least anecdotally,
outcomes can be dramatically improved, although attempts at establishing that there is a measurable
outcome improvement has been difficult in the trial setting. So in summary, modern stroke management now
includes the ability to remove the causative clot endovascularly. Key to success is careful
patient selection and prompt transfer of the patient from the emergency department to the
angiography suite.

14 comments on “Stroke: Endovascular management of ischaemic stroke – radiology video tutorial

  1. It was a pleasure working with Peter on this. Peter has taught me a great deal over the years. It was time he shared his expertise with a wider audience.

  2. Hi Peter, David Witte here Monash Health. I am working with ECR team here at Monash in developing e-learning program for ECR. The objective to inform new team members to the patient journey and how important team work is in effective ECR procedures. I really like your video material and was hoping you approve a link to this video within our learning program?If you have a truncated version of any ECR graphics video, then this would be useful as well. Hope you are well and nice to see you again on webinars I have been studying. All the best [email protected]

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