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Circle of Willis Collateral During Temporary Internal Carotid Artery Occlusion II: Observations From Computed Tomography Angiography

  • Bill Hao Wang (a1), Andrew Leung (a2) and Stephen P. Lownie (a2)

Abstract

Introduction: The Circle of Willis (CoW) is the most effective collateral circulation to the brain during internal carotid artery (ICA) occlusion. Carotid stump pressure (CSP) is an established surrogate measure of the cerebral collateral circulation. This study aims to use hemodynamic and computed tomography angiography measurements to determine the strongest influences upon the dependent variable, CSP. These findings could help clinicians noninvasively assess the adequacy of the collateral circulation and facilitate surgical risk assessment in an outpatient setting. Methods: CSP and mean arterial pressure were measured during carotid endarterectomy or during carotid balloon test occlusion in 92 patients. Intracranial arterial diameters were measured on computed tomography angiography at 16 different locations. Univariate and multivariate analyses were used to determine the key factors associated with CSP. In a subgroup of individuals (n=27) with severe (>70% North American Symptomatic Carotid Endarterectomy Trial) contralateral stenosis or occlusion, the same analysis was performed. Results: The contralateral anterior cerebral artery proximal to anterior communicating artery (A1) of the CoW had the strongest influence upon CSP, followed by the mean arterial pressure, the contralateral ICA diameter, and the anterior communicating artery diameter (R 2=0.364). In the subgroup with high-grade contralateral ICA stenosis, the ipsilateral posterior communicating artery exerted the strongest influence (R 2=0.620). Conclusions: During ICA occlusion, the anterior CoW dominates in preserving collateral flow, especially the contralateral A1 segment. In individuals with high-grade contralateral carotid stenosis, the posterior communicating artery calibre becomes a dominant influence. The most favourable anatomy consists of large contralateral A1 and anterior communicating arteries, and no contralateral carotid stenosis.

Circulation collatérale dans le cercle artériel de Willis pendant une occlusion temporaire de la carotide interne. 2: observations à l’angiographie par tomodensitométrie. Contexte: Le cercle artériel de Willis (CAW) est la circulation collatérale la plus efficace du cerveau pendant une occlusion de la carotide interne (CI). La pression dans le moignon carotidien (PMC) est une mesure substitutive de la circulation collatérale cérébrale. Le but de cette étude était d’utiliser les mesures hémodynamiques et celles de l’angiographie par tomodensitométrie pour déterminer les facteurs qui influencent le plus la variable dépendante, la PMC. Ces observations pourraient aider les cliniciens à déterminer de façon non effractive si la circulation collatérale est adéquate et faciliter l’évaluation du risque chirurgical en externe. Méthodologie: La PMC et la pression artérielle moyenne ont été mesurées chez 92 patients pendant l’endartérectomie carotidienne ou pendant l’épreuve de tolérance à l’occlusion de la carotide par ballonnet. Les diamètres artériels intracrâniens ont été mesurés par angiographie par tomodensitométrie à 16 points différents. Les facteurs clés associés à la PMC ont été déterminés au moyen d’analyses uni et multivariées. Nous avons effectué les mêmes analyses chez un sous-groupe d’individus (n = 27) présentant une sténose controlatérale sévère ou une occlusion (North American Symptomatic Carotid Endarterectomy Trial >70%). Résultats: L’artère cérébrale antérieure controlatérale située à proximité de l’artère communicante antérieure du CAW exerçait la plus forte influence sur la PMC, suivie de la pression artérielle moyenne, du diamètre de la CI controlatérale et du diamètre de l’artère communicante antérieure (R 2 = 0,364). Chez le sous-groupe de patients présentant une sténose de haut degré de la CI controlatérale, c’était l’artère communicante postérieure homolatérale qui exerçait la plus grande influence (R 2 = 0,620). Conclusions: Pendant une occlusion de la CI, le CAW antérieur est le facteur dominant pour la préservation du flux collatéral, particulièrement le segment A1 controlatéral. Chez les individus ayant une sténose carotidienne controlatérale de haut degré, c’est le calibre de l’artère communicante postérieure qui exerce une influence dominante. Les caractéristiques anatomiques les plus favorables sont une A1 controlatérale et des artères communicantes antérieures de gros calibre ainsi que l’absence de sténose de la carotide controlatérale.

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Copyright

Corresponding author

Correspondence to: Stephen P. Lownie, Department of Clinical Neurological Sciences, University Hospital, London Health Sciences Centre, 339 Windermere Road, London, Ontario N6A 5A5. Email: steve.lownie@lhsc.on.ca

References

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1. Alpers, BJ, Berry, RG, Paddison, RM. Anatomical studies of the Circle of Willis in normal brain. AMA Arch Neurol Psychiatry. 1959;81:409-418.
2. Mount, LA, Taveras, JM. Arteriographic demonstration of the collateral circulation of the cerebral hemispheres. Arch Neurol Psychiatry. 1957;78:235-253.
3. Alpers, BJ, Berry, RG. Circle of Willis in cerebral vascular disorders. Arch Neurol. 1963;8:398-402.
4. Schomer, DF, Marks, MP, Steinberg, GK, et al. The anatomy of the posterior communicating artery as a risk factor for ischemic cerebral infarction. N Engl J Med. 1994;330:1565-1570.
5. Hartkamp, MJ, van der Grond, J, de Leeuw, FE, et al. Circle of Willis: morphologic variation on three-dimensional time-of-flight MR angiograms. Radiology. 1998;207:103-111.
6. Liang, F, Fukasaku, K, Liu, H, Takagi, S. A computational model study of the influence of the anatomy of the Circle of Willis on cerebral hyperperfusion following carotid artery surgery. BioMed Engin OnLine. 2011;10:84.
7. Moore, S, David, T. A model of autoregulated blood flow in the cerebral vasculature. Proc Inst Mech Eng H. 2008;222:513-530.
8. Boysen, G. Cerebral perfusion pressure and collateral resistance during carotid clamping. In: Boysen G, eds: Cerebral hemodynamics in carotid surgery. Acta Neurologica Scand Suppl. 1960;49:76-94.
9. Hays, RJ, Levinson, SA, Wylie, EJ. Intraoperative measurement of carotid back pressure as a guide to operative management of carotid endarterectomy. Surgery. 1972;72:953-960.
10. Moore, WS, Hall, AD. Carotid artery back pressure: a test of cerebral tolerance to carotid occlusion. Arch Surg. 1969;99:702-710.
11. Tomura, N, Omachi, K, Takahashi, S, et al. Comparison of technetium Tc 99m hexamethylpropyleneamine oxime single-photon emission tomograph with stump pressure during the balloon occlusion test of the internal carotid artery. AJNR Am J Neuroradiol. 2005;26:1937-1942.
12. Moritz, S, Kasprzak, P, Arlt, M, Taeger, K, Metz, C. Accuracy of cerebral monitoring in detecting cerebral ischemia during carotid endarterectomy – A comparison of transcranial Doppler sonography, near-infrared spectroscopy, stump pressure, and somatosensory evoked potentials. Anesthesiology. 2007;170:563-569.
13. Harada, RN, Comerota, AJ, Good, GM, Hashemi, HA, Hulihan, JF. Stump pressure, electroencephalographic changes, and the contralateral carotid artery: another look at selective shunting. Am J Surg. 1995;170:148-153.
14. Henderson RD, Eliasziw M, Fox AJ, Rothwell PM, Barnett HJM. Angiographically defined collateral circulation and risk of stroke in patients with severe carotid artery stenosis. Stroke. 2000;31:128-132.
15. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med. 1991;325:445-453.
16. Bartlett, ES, Walters, TD, Symons, SP, Fox, AJ. Quantification of carotid stenosis on CT angiography. Am J Neuroradiol. 2006;27:13-19.
17. Alastruey, J, Parker, KH, Peiro, J, Byrd, SM, Sherwin, SJ. Modelling the circle of Willis to assess the effects of anatomical variations and occlusions on cerebral flows. Journal of Biomechanics. 2007;40:1794-1805.

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Circle of Willis Collateral During Temporary Internal Carotid Artery Occlusion II: Observations From Computed Tomography Angiography

  • Bill Hao Wang (a1), Andrew Leung (a2) and Stephen P. Lownie (a2)

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