Ischemic lesion water homeostasis after thrombectomy for large vessel occlusion stroke within the anterior circulation: The impact of age

Abstract

The effect of age on lesion pathophysiology in the context of thrombectomy has been poorly investigated. We aimed to investigate the impact of age on ischemic lesion water homeostasis measured with net water uptake (NWU) within a multicenter cohort of patients receiving thrombectomy for anterior circulation large vessel occlusion (LVO) stroke. Lesion-NWU was quantified in multimodal CT on admission and 24 h for calculating Δ-NWU as their difference. The impact of age and procedural parameters on Δ-NWU was analyzed. Multivariable regression analysis was performed to identify significant predictors for Δ-NWU. Two hundred and four patients with anterior circulation stroke were included in the retrospective analysis. Comparison of younger and elderly patients showed no significant differences in NWU on admission but significantly higher Δ-NWU (p = 0.005) on follow-up CT in younger patients. In multivariable regression analysis, higher age was independently associated with lowered Δ-NWU (95% confidence interval: -0.59 to -0.16, p < 0.001). Although successful recanalization (TICI ≥ 2b) significantly reduced Δ-NWU progression by 6.4% (p < 0.001), younger age was still independently associated with higher Δ-NWU (p < 0.001). Younger age is significantly associated with increased brain edema formation after thrombectomy for LVO stroke. Younger patients might be particularly receptive targets for future adjuvant neuroprotective drugs that influence ischemic edema formation.

Keywords: Stroke; aging; biomarkers; brain edema; brain ischemia; interventional neuroradiology.

Figure 1.

Two examples of quantitative edema imaging in a young patient (left) and elderly patient (right). Admission CT is displayed in the upper row and follow-up CT in the lower row. In admission imaging, CT perfusion-derived cerebral blood volume maps were used to improve the definition of a region of interest for measurements of relative hypoattenuation in non-enhanced CT, based on the equation displayed for %-net increase of water content. “D_T2” refers to the mean density of the ischemic core and “D_T1” refers to the mean density of the physiological density in the contralateral hemisphere. Water uptake maps were generated based on densitometric voxel-wise percent lesion water uptake (right image, lower row).

Figure 2.

Admission (left) net water uptake (NWU) compared by cohorts of younger and elderly patients. Significant distribution of Δ-NWU between both cohorts with significantly elevated ischemic edema formation in younger patients.

Figure 3.

Significant effects of age and recanalization status on Δ net water uptake (NWU) adjusted for baseline NWU.