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Updated: Aug 19, 2026
Bilateral Common Carotid Artery Occlusion as an Adequate Preconditioning Stimulus to Induce Early Ischemic Tolerance to Focal Cerebral Ischemia
Published on: May 9, 2013
Can we identify patients with carotid occlusion who would benefit from EC/IC bypass? Review
Roman Herzig1, Petr Hlustík, Karel Urbánek
1Stroke Center of Department of Neurology, Teaching Hospital, Olomouc, Czech Republic. herzig.roman@seznam.cz
Insights
Internal carotid artery occlusion poses high stroke recurrence risk. Cerebral revascularization, like EC/IC bypass, shows promise for select patients with hemodynamic compromise, despite past study limitations.
Area of Science:
- Neurology
- Neurosurgery
- Vascular Surgery
Background:
- Internal carotid artery occlusion (CAO) leads to high mortality and disability.
- Patients with symptomatic CAO face significant recurrent stroke risk, especially with impaired cerebral vasomotor reactivity (CVR).
- Current treatments include antithrombotic medication and risk factor control; revascularization options like endarterectomy or angioplasty exist for specific stenoses.
Purpose of the Study:
- To re-evaluate the role of extracranial to intracranial (EC/IC) arterial bypass surgery in preventing stroke in patients with symptomatic CAO.
- To highlight the potential benefits of EC/IC bypass in a subgroup of patients with hemodynamic compromise.
- To discuss advancements in diagnostic methods for identifying suitable surgical candidates.
Main Methods:
- Review of historical EC/IC bypass studies, including the EC/IC Bypass Study (1985).
- Discussion of advancements in surgical techniques and diagnostic imaging.
- Exploration of various diagnostic modalities for assessing cerebral hemodynamics and CVR.
Main Results:
- The EC/IC Bypass Study did not confirm bypass effectiveness compared to best medical care.
- Recent evidence suggests EC/IC bypass may be beneficial for specific patient subgroups with hemodynamic compromise.
- Progress in surgical techniques and diagnostics has renewed interest in cerebral revascularization.
Conclusions:
- Despite past study limitations, EC/IC bypass surgery warrants consideration for carefully selected CAO patients.
- Identifying the optimal surgical candidates requires advanced diagnostic tools to assess hemodynamic compromise.
- Further research is needed to refine patient selection criteria for EC/IC bypass.
Abstract:
Occlusion of the internal carotid artery (CAO) is associated with a high mortality rate and frequent disability in survivors. Even in patients with good clinical recovery there is a high risk of recurrent stroke, mainly in those with impaired cerebral vasomotor reactivity (CVR). Current evidence based therapeutic options for patients with symptomatic CAO include antithrombotic medication and control of vascular risk factors. For stenosis of the contralateral internal or ipsilateral external carotid artery, endarterectomy or percutaneous transluminal angioplasty may be considered. Ongoing symptoms may cease after tapering antihypertensive medications. Extracranial to intracranial (EC/IC) arterial bypass surgery has been used since 1967 in patients with CAO. However, the international randomized EC/IC Bypass Study (1985) failed to confirm the effectiveness of EC/IC bypass for preventing cerebral ischemia in patients with symptomatic CAO when compared to those assigned to the best medical care. Nevertheless, the conclusion of the EC/IC Bypass Study has several objections and downfalls. Since then, there has been a revival of interest in cerebral revascularization procedures owing to the substantial progression of surgical techniques and the use of more advanced diagnostic methods. Thus, it has recently been reported that EC/IC bypass surgery can be useful in preventing stroke in patients with hemodynamic compromise. The main problem is to identify the small subgroup of surgical candidates. Presently, single photon emission computed tomography (SPECT), positron emission tomography (PET), transcranial Doppler sonography (TCD), computed tomography (CT) with administration of (133)Xe, perfusion CT, near infrared spectroscopy (NIRS), and functional magnetic resonance imaging (fMRI) are being used for this purpose.
