Evaluation by “statistical parametric mapping” of cerebral perfusion changes in patients with carotid artery stenosis after endarterectomy

Abstract

The efficacy of carotid endartectomy (CE) in cerebrovascular accidents produced by carotid stenosis can be evaluated with the cerebral perfusion with single photon emission tomography, using statistical parametric mapping (SPM).

Material and methods

Twelve patients with significant carotid stenosis who underwent endartectomy were included in the study. All underwent a cerebral perfusion study with ^99mTc-ethylene dicysteine diethyl ester (ECD) at baseline and after the endartectomy. Using SPM, the baseline/post-surgery study was compared independently with the control group made up of 20 patients and the corresponding parametric statistical mappings were obtained. Changes in extension (k_E or voxel number) and intensity (change in the T value) of the significantly hypoperfused zones and direction of these changes were evaluated.

Results

In the group of 12 patients, improvement of the post-surgical cerebral perfusion was observed in 5 patients with an average 50.56% decrease in the extension of the hypoperfused zones and average 30.9% decrease of intensity. Four patients showed an average 85.53% increase in the extension of cerebral hypoperfusion and of 34.21% in intensity. No significant changes between both studies were found in three patients.

Conclusions

SPM has been shown to be a useful tool that makes it possible to objectify the cerebral blood flow changes produced after the surgical intervention, evaluating the changes in extension and intensity of the significantly hypoperfused zones.