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Identification of Hemodynamic Patients for EC-IC Bypass Surgery

  • S. Vorstrup
  • J. Schmidt
  • G. Waldemar
  • J. Haase
  • O. B. Paulson
Conference paper

Abstract

Recurrent ischemic symptoms from a hemisphere where the internal carotid artery (ICA) is occluded are either embolic or hemodynamic. Distinguishing between these two etiologies is not possible on clinical grounds alone, although multiple, brief attacks including limb shaking are suggestive of hemodynamic origin (Levine et al. 1989). In particular, when the symptoms occur in relation to orthostatic changes, a clinical suspicion of an inadequate regional flow arises. Nevertheless, in most of these patients the setting of clinical symptoms alone and even when supplemented by angiography and CT will not identify the hemodynamic cases, and additional studies are needed. Measurement of CBF during CO2 inhalation (Levine et al. 1989; Norrving et al. 1982) or after intravenous administration of acetazolamide (Vorstrup et al. 1986) has been used to evaluate the cerebral vasodilatory capacity. The development of positron emission tomography has permitted concomitant measurement of CBF, oxygen extraction fraction, and cerebral metabolism for oxygen (CMRO2), which identifies critically perfused areas during baseline conditions. In addition, measurement of CBF and cerebral blood volume (CB) can be applied for this purpose (Gibbs et al. 1984).

Keywords

Internal Carotid Artery Mean Arterial Blood Pressure Cerebral Blood Volume Oxygen Extraction Fraction Carotid Artery Occlusion 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. EC-IC Bypass Study Group (1985) Failure of extracranial-intracranial arterial bypass to reduce the risk of ischemic stroke. Results of an international randomized trial. N Engl J Med 313:1191–1200CrossRefGoogle Scholar
  2. Gibbs JM, Leenders KL, Wise RJS, Jones T (1984) Evaluation of cerebral perfusion reserve in patients with carotid artery occlusion. Lancet 1:310–314PubMedCrossRefGoogle Scholar
  3. Levine RL, Lagreze HL, Dobkin JA, Hanson JM, Satter MR, Rowe BR, Nickles RJ (1989) Cerebral vasocapacitance and TIAs. Neurology 39:25–29PubMedGoogle Scholar
  4. Norrving B, Nilsson B, Risberg J (1982) rCBF in patients with carotid occlusion: resting and hypercapnic flow related to collateral flow pattern. Stroke 13:155–162PubMedCrossRefGoogle Scholar
  5. Powers WJ, Tempel LW, Grubb RL (1989) Influence of cerebral hemodynamics on stroke risk: one-year follow-up of 30 medically treated patients. Ann Neurol 25:325–330PubMedCrossRefGoogle Scholar
  6. Vorstrup, S, Brun B, Lassen NA (1986) Evaluation of the cerebral vasodilatory capacity by the acetazolamide test before EC-IC bypass surgery in patients with occlusion of the internal carotid artery. Stroke 17:1291–1298PubMedCrossRefGoogle Scholar
  7. Vorstrup S (1988) Tomographic cerebral blood flow measurements in patients with ischemic cerebrovascular disease and evaluation of the vasodilatory capacity by the acetazolamide test. Acta Neurol Scand [Suppl 114] 77:1–48Google Scholar

Copyright information

© Springer-Verlag, Berlin Heidelberg 1992

Authors and Affiliations

  • S. Vorstrup
  • J. Schmidt
  • G. Waldemar
  • J. Haase
  • O. B. Paulson

There are no affiliations available

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