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[Effect of thrombus endarterectomy (TEA) on the regional cerebral bloodflow (rCBF) in patients with unilateral internal carotid artery stenosis].

AIM
In a study of patients with unilateral and symptomatic stenosis of the internal carotid artery (ICA), the effect of endarterectomy (EA) on the regional cerebral blood flow (rCBF) was tested over a postoperative interval of 12 months.


METHOD
Xenon-133-rCBF was assessed in 74 patients pre- and post-surgery (one week, six weeks, three months and 12 months after EA). This was done at rest and after stimulation with acetazolamide in order to test the perfusion reserve.


RESULTS
Before surgery all 74 patients showed a diminished perfusion ipsilaterally-at rest and/or after stimulation. 38/74 (51%) patients had a significant (> 5%) and 36/74 (49%) patients a non-significant (< 5%) interhemispheric perfusion asymmetry. Twelve months after EA, there were only 23/74 (31%) patients with significant interhemispheric perfusion asymmetry. By stimulation, this decreasing effect became more evident: Before surgery 44/74 (60%) patients had a significant interhemispheric perfusion asymmetry, 12 months after surgery there were only 14/74 (19%) patients.


CONCLUSION
In regard to the brain hemisphere distal to the ICA stenosis, our study revealed a significant improvement of brain perfusion after EA. Brain perfusion was stable over an interval of 12 months post-surgery. By EA, especially the perfusion reserve increased, as shown by a normal acetazolamide test. Hence, Xenon-133-rCBF could be shown to be an important method in the evaluation of the indication for surgery and of the result of it. In the intra-individual follow-up after EA, rCBF was able to identify hypoperfusion and may help decide, whether re-angiography is necessary or not.