Brain Disorders & Therapy

The collateral circulation determines cortical infarct volume in anterior circulation ischemic stroke

Global Summit on Stroke

August 03-05, 2015 Birmingham, UK

Hen Hallevi

Posters-Accepted Abstracts: Brain Disord Ther

Abstract:

Background: Acute ischemic stroke (AIS) is a common neurological event that causes varying degrees of disability. AIS
outcome varies considerably from complete recovery to complete loss of tissue and function. This diversity is partly explained
by the compensatory ability of the collateral circulation and the ensuing cerebral flow status. The collateral flow to the anterior
circulation largely supplies the cortical areas. The deep brain tissue is supplied by penetrating arteries and has little or no
collateral supply. Although these brain compartments differ substantially in their collateral supply, there are no published
data on the different effects the collateral circulation has on them. In addition, the influence of baseline collateral flow on the
final infarct size following endovascular or reperfusion therapies remains unknown. This study was designed to determine the
effect of the collateral circulation on cortical infarct volume and deep infarct volume and to investigate the relation between
the collateral status, response to reperfusion therapy and clinical outcome.
Methods: We studied consecutive patients presenting to our medical center between April 2008 and April 2012 with AIS
and anterior proximal artery occlusion. To be included, patients have had to have undergone a computerized tomographic
angiographic study within 12 hours of symptom onset demonstrating the occlusion. Imaging data and clinical and laboratory
values were extracted retrospectively from the original scans and medical records. Clinical outcome was assessed at discharge
using the modified Rankin Scale (mRS).
Results: Of the 51 study patients, 13 were treated conservatively, 22 received intravenous recombinant tissue plasminogen
activator and 16 received intra-arterial thrombolysis. The collateral grading was similar for all three treatment groups. The
CIV highly correlated with the collateral status (r=-0.73 P<0.001), but the DIV did not (P=.122). There was also a high
correlation between the CIV and the mRS (P<.001) anda highly linear correlation between the collateral status and the CIV
in the conservative treatment group (r=-0.97, P<.001) but this association was much lower in patients that were successfully
recanalized.
Conclusions: Our data show that the collateral circulation is an important determinant of cortical damage and in turn, of
clinical outcome in the setting of anterior circulation major artery occlusion. Our findings further demonstrate the benefit of
recanalization in sparing cortical tissue from injury. Additional studies are needed to determine the impact of stroke therapy
on the final infarct volume in relation to the collateral status.