Background and Purpose: Congenital vertebral artery (VA) hypoplasia is an uncommon embryonic variation of posterior circulation. The frequency of this congenital variation was reported to be 2–6% from autopsy and angiograms. The aim of our study was to elucidate the role of VA hypoplasia in acute ischemic stroke. Method: We examined 191 acute ischemic stroke patients (age 55.8 ± 14.0 years). TOAST subtypes were determined. A cervical magnetic resonance angiogram was performed in every patient. A duplex study of bilateral VA with flow velocities and vessel diameter recording in the intertransverse (V2) segment was performed within 72 h after onset of ischemic stroke. The net VA flow volume was measured in each subject. Result: The overall incidence of a unilateral congenital hypoplastic VA was 11.51%, which was statistically higher especially in cases of brainstem/cerebellar infarction. Of these, subjects with VA hypoplasia had an etiological preponderance of the ‘large-artery atherosclerosis’ subtype and a topographic preponderance of ipsilateral posterior circulation infarction. Conclusions: Based on our results, VA hypoplasia seemed a contributing factor of acute ischemic stroke, especially in posterior circulation territories.

Keywords:
Vertebral artery, flow volume, Vertebrobasilar ischemia
1.
Seidel E, Eicke BM, Tettenborn B, Krummenauer F: Reference values for vertebral artery flow volume by duplex sonography in young and elderly adults. Stroke 1999;30:2692–2696.
2.
Saito K, Kimura K, Nagatsuka K, Nagano K, Minematsu K, Ueno S. Naritomi H: Vertebral artery occlusion in duplex color-coded ultrasonography. Stroke 2004;35:1068–1072.
3.
Oder B, Oder W, Lang W, Marschnigg E, Deecke L: Hypoplasia, stenosis and other alterations of the vertebral artery: does impaired blood rheology manifest a hidden disease? Acta Neurol Scand 1998;97:398–403.
4.
Delcker A, Diener HC, Timmann D, Faustmann P: The role of vertebral and internal carotid artery disease in the pathogenesis of vertebrobasilar transient ischemic attacks. Eur Arch Psychiatry Clin Neurosci 1993;242:179–183.
5.
Nicolau C, Gilabert R, Garcia A, Blasco J, Chamorro A, Bru C: Effect of internal carotid artery occlusion on vertebral artery blood flow: a duplex ultrasonographic evaluation. J Ultrasound Med 2001;20:105–111.
6.
Chaturvedi S, Lukovits T, Chen W, Gorelick PB: Ischemia in the territory of a hypoplastic vertebrobasilar system. Neurology 1999;52:980–983.
7.
Bendick PJ, Glover JL: Vertebrobasilar insufficiency: evaluation by quantitative duplex flow measurements. J Vasc Surg 1987;5:594–600.
8.
Fisher CM, Gore I, Okabe N, White PD: Artherosclerosis of the carotid and vertebral arteries – extracranial and intracranial. J Neuropathol Exp Neurol 1965;24:455–476.
9.
Harold P, Birgitte H, Jaap K, Jose B, Betsy B, David L, Eugene M: Classification of subtype of acute ischemic stroke: definitions for use in a multicenter clinical trial. Stroke 1993;24:35–41.
10.
Chaturvedi S, Lukvits T, Chen W, Gorelick P: Ischemia in the territory of a hypoplastic vertebrobasilar system. Neurology 1999;52:980–983.
11.
Acar M, Degirmenci B, Yucel A, Albayrak R, Haktanir A: An evaluation of internal carotid artery and cerebral blood flow volume using color duplex sonography in patients with vertebral artery hypoplasia. Eur J Radiol 2005;53:450–453.
12.
Battacharji SK, Hutchinson EC, McCall AJ: The circle of Willis – The incidence of developmental abnormalities in normal and infarcted brains. Brain 1967;90:747–758.
© 2006 S. Karger AG, Basel
2006
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