If the ICA is blocked is it even a stroke since that is prior to entering the Circle of Willis? And if the Circle of Willis is complete then that wouldn't cause problems. Is this problem even defined correctly?
http://www.medpagetoday.com/Cardiology/Strokes/55888?xid=nl_mpt_cardiodaily_2016-01-28&eun=gd3r
The magnitude of functional outcome benefits from reperfusion with
endovascular thrombectomy may depend on the site of occlusion, a
meta-analysis showed.
Reperfusion was associated with 3.5-fold higher odds of a good
functional outcome (0-2 on the modified Rankin Scale) at 90 days among
patients with internal carotid artery (ICA) occlusions and 6.2-fold
higher among those with proximal middle cerebral artery (MCA) occlusions
versus persistent occlusion.
Reperfusion had no significant association with
good functional outcome
in distal MCA lesions (OR 1.4, 95% confidence interval 0.8-2.6),
although there was a link in the M2 occlusion subset (OR 2.2, 95% CI
1.0-4.7),
Robin Lemmens, MD, PhD, of University Hospitals Leuven in Belgium, and colleagues reported online in
Neurology.
"The association between reperfusion and good clinical outcomes is
stronger in patients with proximal(closer) occlusions compared to distal(farther)
occlusions," the group concluded. "Our results, however, do not indicate
that patients with distal MCA occlusions do not benefit from
endovascular therapy."
"In contrast, the results underscore the need for additional clinical
trial data to determine the effect of endovascular therapy in this
subgroup," they continued.
Indeed, the study "is not going to change my practice,"
Haitham Dababneh, MD, of Doctors Hospital at Renaissance in Edinburg, Texas, told
MedPage Today. He
likewise called for better data from randomized controlled trials,
noting differing baseline characteristics between groups in the
meta-analysis and the fact that there were fewer patients with distal
strokes than proximal strokes.
For now, "it's hard to compare apples to oranges," Dababneh said.
As
for the reason why patients with distal MCA occlusions might show less
benefit from reperfusion, the authors suggested that those individuals
"have less brain tissue at risk of infarction (i.e., less brain tissue
that can be salvaged with reperfusion) compared to patients with more
proximal MCA or ICA occlusions."
Lemmens and colleagues pooled patient-level data from four large
endovascular trials -- SWIFT, STAR, DEFUSE 2, and IMS III -- for a
total of 710 patients in their analysis.
Panagiotis Papanagiotou, MD, of Hospitals Bremen-Mitte in Germany, told
MedPage Today that clinicians should focus on careful patient selection, perhaps with advanced imaging techniques.
Papanagiotou, who was an investigator for SWIFT, added that the
improvement of endovascular techniques -- such as "direct thrombus
aspiration to achieve higher recanalization rates" -- may also be
helpful for the treatment of distal lesions.