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Long-term hemodynamic effects of carotid endarterectomy
M Kluytmans1, J van der Grond, B C Eikelboom
1Department of Radiology, University Hospital Utrecht, The Netherlands. manon.kluytmans@isi.uu.nl
Insights
Carotid endarterectomy (CEA) significantly improves cerebral circulation in patients with severe internal carotid artery (ICA) stenosis and contralateral ICA occlusion. However, for patients with severe ICA stenosis but no contralateral occlusion, CEA offers negligible hemodynamic benefits.
Area of Science:
- Neurology
- Vascular Surgery
- Medical Imaging
Background:
- Hemodynamic factors influencing carotid endarterectomy (CEA) benefits in severe internal carotid artery (ICA) stenosis remain unclear.
- Investigating hemodynamic changes due to severe ICA stenosis and post-CEA alterations is crucial.
Purpose of the Study:
- To assess hemodynamic changes associated with severe ICA stenosis.
- To evaluate hemodynamic alterations following CEA in these patients.
Main Methods:
- Dynamic susceptibility contrast MRI used to acquire hemodynamic parameters.
- Regional cerebral blood volume (rCBV) and mean transit time (MTT) measured in 19 severe ICA stenosis patients and 33 controls.
- MRI scans analyzed for gray and white matter segmentation.
Main Results:
- No significant rCBV or MTT differences found ipsilateral to stenosis, nor post-CEA.
- Contralateral hemisphere changes observed only in patients with contralateral ICA occlusion.
- Post-CEA, hemodynamic parameters normalized in patients with contralateral occlusion.
Conclusions:
- CEA improves cerebral circulation in severe ICA stenosis patients with contralateral ICA occlusion.
- Hemodynamic effects of CEA are negligible in severe ICA stenosis patients without contralateral ICA occlusion.
Background And Purpose:
The presence and importance of hemodynamic factors to the beneficial effect of carotid endarterectomy (CEA) in patients with severe stenosis of the internal carotid artery (ICA) is unclear. The purpose of this study was to investigate possible hemodynamic changes caused by a severe ICA stenosis and the subsequent changes after CEA.
Methods:
Hemodynamic parameters were acquired with dynamic susceptibility contrast MRI. Regional cerebral blood volume (rCBV), mean transit time (MTT), time of appearance, and time to peak were determined in 19 patients with severe stenosis (>70%) of the ICA before and after CEA and in 33 control subjects. Four patients had an occlusion of the contralateral ICA. Corresponding T2-weighted MRI and inversion recovery MRI scans were used for segmentation of gray and white matter regions.
Results:
In the hemisphere ipsilateral to the stenosed ICA, no significant differences were found for the rCBV or MTT between patients and control subjects. Also, no significant alterations in these two parameters were observed after CEA. In the hemisphere contralateral to the stenosed ICA, hemodynamic changes were observed only in patients with an ICA occlusion contralateral to the stenosed ICA. In these patients, rCBV, MTT, time of appearance, and time to peak were all increased in the contralateral hemisphere. After CEA, all hemodynamic parameters fell in the normal range.
Conclusions:
Although CEA does improve the cerebral circulation in patients with a severe stenosis and a contralateral ICA occlusion, the hemodynamic effects of CEA in patients with severe stenosis without a contralateral ICA occlusion are negligible.