# Recanalization status and temporal evolution of early ischemic changes following stroke thrombectomy

## TL;DR

This study examines how early brain changes after stroke evolve over time, depending on whether blood flow is successfully restored.

## Contribution

The study reveals that successful recanalization affects cortical regions in ICA/M1 stroke patients but not deep structures or M2 patients.

## Key findings

- Successful recanalization (mTICI 3) was associated with less severe early ischemic changes in cortical regions of ICA/M1 patients.
- Ischemic changes detected at baseline remained unchanged in follow-up scans, regardless of recanalization success.
- Recanalization effects were not observed in deep brain structures or in patients with M2 occlusions.

## Abstract

Present-day computer tomography (CT) scanners have excellent spatial resolution and signal-to-noise ratio and are instrumental detecting early ischemic changes (EIC) in brain. We assessed the temporal changes of EIC based on the recanalization status after thrombectomy.

The cohort comprises consecutive patients with acute ischemic stroke in anterior circulation treated with thrombectomy in tertiary referral hospital. All baseline and follow-up scans were screened for any ischemic changes and further classified using Alberta Stroke Program Early CT Score (ASPECTS). Generalized linear mixed models were used to analyze the impact of recanalization status using modified Thrombolysis in Cerebral Infarction (mTICI) on temporal evolution of ischemic changes.

We included 614 patients with ICA, M1, or M2 occlusions. Median ASPECTS score was 9 (IQR 7–10) at baseline and 7 (5-8) at approximately 24 h. mTICI 3 was achieved in 207 (33.8%), 2B 241 (39.3%), 2A in 77 (12.6%), and 0–1 in 88 (14.3%) patients. Compared to patients with mTICI 3, those with mTICI 0–1 and 2A had less favorable temporal changes of ASPECTS (p < 0.001). Effect of recanalization was noted in the cortical regions of ICA/M1 patients, but not in their deep structures or patients with M2 occlusions. All ischemic changes detected at baseline were also present at all follow-up images, regardless of the recanalization status.

Temporal evolution of the ischemic changes and ASPECTS are related to the success of the recanalization therapy in cortical regions of ICA/M1 patients, but not in their deep brain structures or M2 patients. In none of the patients did EIC revert in any brain region after successful recanalization.

Graphical abstract