Peter Jan Van Laar MD, Presenter: Nothing to Disclose

Jeroen van der Grond, Abstract Co-Author: Nothing to Disclose

Reinoud P.H. Bokkers MD, Abstract Co-Author: Nothing to Disclose

Karin Klijn, Abstract Co-Author: Nothing to Disclose

Jeroen Hendrikse MD, PhD, Abstract Co-Author: Nothing to Disclose

To prospectively investigate the qualitative and quantitative contribution of the ipsilateral external carotid artery (ECA) to cerebral perfusion in patients with symptomatic internal carotid artery (ICA) occlusion.

Institutional review board approval and informed consent were obtained. Thirty functionally independent patients (24 men, 6 woman; mean age 63 years) with symptomatic unilateral ICA occlusion were included. Grading of ECA collateral flow was performed with intraarterial digital subtraction angiography (DSA). The quantitative contribution of the ECA to regional cerebral blood flow (rCBF) was assessed with selective arterial spin labeling MRI. Differences in rCBF were analyzed with Student’s t-test.

Twenty percent of the patients had ECA grade 1 collateral flow (no filling of carotid siphon), 20% grade 2 (filling of carotid siphon), and 60% grade 3 (filling of anterior or middle cerebral artery). In patients with grade 2 ECA collateral flow, the ECA supplied a smaller part of the brain compared with patients with grade 3 ECA collateral flow. No significant difference (P = .70) was found in rCBF values of the perfusion territories supplied by the ECA between patients with grade 2 (57 ± 16 ml/min/100gr) and patients with grade 3 (60 ± 12 ml/min/100gr).

In patients with symptomatic ICA occlusion, often focal brain regions strongly depend on the contribution to cerebral perfusion of the ECA ipsilateral to the side of the ICA occlusion, even in patients with a limited ECA collateral supply on intraarterial DSA.

In patients with ECA stenosis ipsilateral to an ICA occlusion, knowledge of the quantitative contribution of the ECA may help to select patients who may benefit most from endarterctomy of the ECA.

Van Laar, P, van der Grond, J, Bokkers, R, Klijn, K, Hendrikse, J, Assessment of the Qualitative and Quantitative Contribution of the External Carotid Artery to Brain Perfusion in Patients with Symptomatic Internal Carotid Artery Occlusion.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5010215.html