# Distance to thrombus, ischemic lesion volume and clinical outcome after thrombectomy for M1 middle cerebral artery occlusion

## TL;DR

This study shows that the distance to a blood clot in the brain is linked to smaller stroke damage and better recovery after treatment.

## Contribution

The study identifies distance to thrombus as a novel predictor of stroke lesion size and clinical outcomes after thrombectomy.

## Key findings

- Greater distance to thrombus was associated with smaller ischemic lesion volume.
- More distal thrombi correlated with better clinical outcomes at 3 months.
- Ischemic lesion volume was inversely related to favorable clinical outcomes.

## Abstract

Stroke resulting from occlusion of the middle cerebral artery (MCA) can have devastating consequences, potentially leading to a loss of independence. This study aimed to investigate the relationship between the distance to the thrombus (DT) and both ischemic lesion volume (ILV) and clinical outcomes.

We retrospectively evaluated patients with thromboembolic MCA M1 segment occlusion who underwent neurovascular imaging followed by endovascular thrombectomy (EVT) at two comprehensive stroke centers over a 3-year period (2018–2020). Preinterventional computed tomography (CT) or magnetic resonance (MR) angiography was used to measure DT, defined as the distance from the carotid‑T bifurcation to the proximal surface of the M1 occlusion. Postinterventional CT or MR imaging was employed to determine the ILV and clinical outcomes were assessed using the modified Rankin scale (mRS) at 3 months.

There were 346 patients evaluated. The median DT was 9.4 mm (interquartile range, IQR 6.0–13.7 mm) and the median ILV was 13.9 ml (IQR 2.2–53.1 ml). After adjustment, an increase in DT was associated with a decrease in odds for a larger ILV (odds ratio, OR 0.96, 95% confidence interval, CI 0.92–0.99, p = 0.041). Through this association, more distal thrombi were associated with good clinical outcome (mRS 0–2; clinical outcome available in 282 patients, p = 0.018). The ILV was inversely associated with better clinical outcome OR 0.52 (95% CI 0.40–0.67).

Based on the findings, DT was identified as an independent albeit weak predictor for ILV and clinical outcomes in patients with MCA M1 occlusion who underwent EVT.

The online version of this article (10.1007/s00508-024-02364-y) contains supplementary material, which is available to authorized users.