Endovascular Treatment Not Superior to Intravenous TPA for Acute Stroke

A study published in the New England Journal of Medicine (6 Feb 2013) did not find different outcomes of acute stroke patients treated with endovascular therapy vs intravenous TPA

Background

• IV recombinant tissue plasminogen activator (t-PA) is the standard treatment for acute ischemic stroke
• Endovascular (intraarterial) treatment has higher recanalization rates but whether this translates into more favorable clinical outcome is unknown
• Prior trials of endovascular treatment showed promising results but there were problems with 1) limited generalizability, 2) lack of comparison between endovascular Rx and IV t-PA, 3) endovascular Rx was not assessed as a multimodality procedure

Study Methods and Results

• Multicenter, open-treatment clinical trial with a blinded end point
• Questions: whether outcomes were better with endovascular Rx than with IV t-PA
• Included patients are between 18-80 years, with a clearly defined time of stroke onset that was less than 4.5 hours (for IV t-PA) or 6 hours (for endovascular Rx)
• 362 patients with acute ischemic stroke were randomized to either endovascular Rx (IA thrombolysis with rt-PA, mechanical clot disruption or retrieval, or a combination of these) or to IV rt-PA
• Primary outcome = disability-free survival at 90 days, secondary outcome = proportion of patients with mild neurologic deficit or none and several safety measures
• Disability-free survival at 90 days = 30% in endovascular group, 35% in IV group. This did not change after adjustment for age, sex, stroke severity or presence of atrial fibrillation

Reference:
Ciccone A et al. Endovascular treatment for acute ischemic stroke. N Eng J Med 2013 Feb 6.
Read the full study HERE

Carotid Cavernous Fistula (CCF)

The author would like to thank Drs Thanwa Sudsang and Tom Osborne for helping with labeling the vessels in these angiographic images.

AP and lateral views of the right carotid artery injection show simultaneous opacification of venous structures (superior/inferior ophthalmic veins, middle cerebral vein) and dilatation of the veins due to the presence of CCF in this patient who had recent head trauma.

Facts: CCF

• Rent in the wall of cavernous carotid artery with fistulous communication to the venous spaces of the cavernous sinus
• Either due to trauma (post-traumatic CCF) or ruptured cavernous carotid artery aneurysm
• Traumatic CCF typically seen in young adult male, post motor vehicle collision
• Non-traumatic CCF seen in elderly, female more common than male
• Clinical: venous hypertension (i.e., proptosis, chemosis, retinal hemorrhage, headache)
• Feared complication: venous hypertension of deep vein system and subsequent venous infarction (this can occur if flow from carotid into the cavernous sinus is diverted into deep venous system)

Urgent Treatment Required If:

• Worsening symptoms: increasing proptosis, diminishing visual acuity, increasing intraocular pressure, elevated intracranial pressure
• Extension of pseudoaneurysm or venous varix, or rupture into subarachnoid space

Treatment: endovascular occlusion of fistula with a detachable balloon device, while preserving flow in the carotid artery. Coil embolization is an alternative possible treatment.

Reference:

Morris P. Practical Neuroangiography, 2nd edition, 2007.

Step Lightly for Kids

The Alliance for Radiation Safety in Pediatric Imaging has recently offered free materials on dose reduction for interventional radiology procedures, and patient education materials. These have been endorsed by the American College of Radiology (ACR).

"Treat kids with care:

Step lightly on the fluoroscopy pedal.

Stop and child-size the technique.

Consider ultrasound or, when applicable, MRI guidance."

On their website "ImageGently.org", slide presentations, checklists, outlines and patient brochures are available for free download.

Above image from www.ImageGently.org

Intracranial Aneurysms: Coil Embolization

Fig.1 & 2: Angiographic image of the left internal caroid artery injection shows an aneurysm of the left supraclinoid internal carotid artery. Fig.1 without subtraction, Fig.2 with.
Fig.3: Angiographic image after coil embolization (performed because the patient had SAH) reveals a coil within the aneursym.

Coil Embolization Complications

• Complicaton rate 8.6% to 18.6% (median 10.6%), lower than surgical clipping
• Common complications: thrombo-embolic events, perforation of aneurysm, parent artery obstruction, collapsed coil, coil malposition, and coil migration

Coil Embolization versus Aneurysm Clipping

• Less risks of death
• Higher rate of rebleeding (2.4% versus 1%) - why*
  
• Advantages vary depending on location of aneurysm, but coil embolization is beneficial for all sites

*Percentage of complete aneurysm occlusion after coil embolization is lower than with surgical clipping
* Recurrence = refilling of thee neck, sac, dome of a successfully treated aneurysm

What to Choose?

• Not all aneurysms required coil embolization. This depends on size, anatomy and location of aneurysms.
  
• People at increased risk for craniotomy (>65 years, poor clinical status, comorbid conditions)
• Suitability depends on size, anatomy, location of aneurysms (in ophthalmic artery or basilar tip artery)
• Better perform craniotomy if
• >10 mm size
• > 4mm neck
  

Reference:
Ontario Heath Technology Advisory Committee. Coil Embolization for intracrinal aneurysms.