Cerebral microstructural white matter changes measured by diffusion tensor imaging in asymptomatic carotid endarterectomy patients: a prospective study into predictors and correlation with vascular anatomy
Author Block: C. Péter, B. Szilveszter, M. Vecsey-Nagy, S. Borzsák, G. Gyebnár, Z. Mihály, Z. Czinege, P. Sótonyi, A. Varga; Budapest/HU
Purpose: Diffusion tensor imaging (DTI) metric changes were assessed in a prospective cohort of asymptomatic carotid endarterectomy (CEA) patients in correlation with patient characteristics, and vascular anatomy (4-axis; circle of Willis [CW] scores).
Methods or Background: Prospectively enrolled patients (54, males 54%, age 69.7±7 years) had DTI pre-CEA (mean 2, range 0-31 days) and post-CEA (mean 2, range 0-5 days). DTI metrics (FA–fractional anisotropy, axial, mean, radial diffusivities – AD, MD, RD) were calculated for 16 white matter (WM) regions (8-8 regions of index and contralateral hemispheres) pre-CEA and post-CEA and compared using the repeated measure Wilcoxon signed rank test (p<0.0125, Bonferroni corrected). Preoperative supraaortic plus intracranial CTA was performed to create the 4-axis score (range 0-15,mthe lower the worse) and CW score (0–5, 0 if both the anterior plus ispilateral posterior semicircles towards the operated internal carotid artery are incomplete). Univariate and multivariate linear regression analyses were used to correlate main demographic, comorbidity data, vascular scores (p<0.05).
Results or Findings: Significantly decreased FA in 1/8 index WM region (p=0.007), singificantly increased AD in 7/8 index, 4/8 contralateral WM regions (p<0.0001-0.0120), significantly increased MD in 6/8 index, 4/8 contralateral WM regions (p<0.0001-0.005), significantly increased RD in 5/8 index, 3/8 contralateral WM regions (p<0.0001-0.011) was found. In 19/26 regions with significant DTI metric changes from pre-to-post-CEA, the 4-axis score was a significant predictor using univariate regression analysis (p<0.001-0.038), remaining significant with multivariate regression analysis in the index temporal, contralateral frontal, parietal WM regions (p=0.006-0.012) for MD, and in the index insular (p= 0.042) and temporal WM regions (p=0.039) for RD.
Conclusion: DTI metric changes suggesting microstructural deterioration were found from pre-CEA to post-CEA, more pronounced on the index side, with the weighted 4-axis score as a significant predictor.
Limitations: Identified limitations were (1) the small cohort and (2) the lack of correlation with surgical/anaesthesiology data.
Funding for this study: Funding was received from the National Research, Development and Innovation Office – NKFIH, K 129277.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the institutional ethical committee with approval code: IV/667-1/2022/EKU.