Related Experiment Videos
Carotid endarterectomy, siphon stenosis, collateral hemispheric pressure, and perioperative cerebral infarction
R S Lord1, T B Raj, A R Graham
1Department of Vascular Surgery, St. Vincent's Hospital, Darlinghurst, NSW, Australia.
Insights
Moderate intracranial carotid artery stenosis (50-80%) does not elevate stroke risk after carotid endarterectomy. Postoperative strokes occurred only in patients with compromised collateral circulation, not those with moderate siphon stenosis.
Area of Science:
- Vascular Surgery
- Neurology
- Cerebrovascular Disease
Background:
- Carotid endarterectomy is a procedure to prevent stroke.
- The role of moderate intracranial internal carotid artery stenosis in perioperative stroke risk is unclear.
Purpose of the Study:
- To investigate if moderate stenosis (50-80%) of the internal carotid artery's intracranial segment increases cerebral infarction risk after carotid endarterectomy.
Main Methods:
- Review of arteriograms, ocular pneumoplethysmograms, and internal carotid back pressure.
- Analysis of clinical outcomes in 169 carotid endarterectomy patients.
- Exclusion of siphon stenoses <50% and >80%.
Main Results:
- Moderate siphon stenosis (50-80%) was present in 37 vessels (24 ipsilateral, 13 contralateral).
- Three strokes occurred post-operation; none were associated with moderate siphon stenosis.
- Stroke was observed exclusively in patients with inadequate collateral circulation to the affected hemisphere.
Conclusions:
- Moderate intracranial internal carotid artery stenosis does not heighten the risk of perioperative cerebral infarction.
- Cerebral infarction after carotid endarterectomy is linked to poor collateral supply, not moderate siphon stenosis.
Abstract:
To determine whether moderate stenosis (50% to 80%) of the intracranial segment of the internal carotid artery increases the risk of cerebral infarction after carotid endarterectomy, the arteriograms, ocular pneumoplethysmograms, internal carotid back pressure, and clinical outcome after 169 operations were reviewed. Siphon stenoses less than 50% were not included because of their doubtful anatomic and hemodynamic significance. No patients with stenosis greater than 80% underwent operation. Moderate siphon stenosis affected 37 vessels, 24 (14.2%) ipsilateral and 13 (7.6%) contralateral to the side of operation. Eight patients had bilateral siphon stenosis. Three patients had stroke after operation; none of these cases had siphon stenosis. Moderate siphon stenosis did not increase the risk of perioperative cerebral infarction. Stroke only occurred in those patients in whom there was arteriographic or functional evidence that the affected hemisphere was isolated from effective collateral vessels.