# Effects of thrombus migration on endovascular treatment outcomes in patients with ischemic stroke: a systematic review and meta-analysis

## TL;DR

This study finds that clot migration during stroke treatment is linked to better recovery outcomes, though it doesn't improve survival or reperfusion rates.

## Contribution

The study clarifies the clinical impact of thrombus migration during endovascular stroke treatment through a systematic review and meta-analysis.

## Key findings

- Thrombus migration is associated with better 90-day functional outcomes in stroke patients.
- Thrombus migration does not significantly affect mortality or reperfusion success rates.
- Clot migration may restore blood flow to larger brain areas despite complicating complete revascularization.

## Abstract

Stroke is the world’s second-leading cause of death, with ischemic events accounting for nearly 9 of 10 cases. Rapid endovascular treatment (EVT) is now standard, yet the benefit of giving intravenous tPA beforehand (“bridging therapy”) remains uncertain. One reason: tPA often shifts the clot distally—thrombus migration (TM)—a phenomenon seen in roughly one-fifth of large-vessel strokes that can complicate the procedure but has also been linked to better outcomes. This study evaluates how TM influences clinical outcomes, aiming to clarify whether tPA adds value in patients who receive EVT.

A comprehensive literature search was conducted across various databases until April 2025 to identify relevant articles. The quality was assessed using the NOS tool and the analysis was performed using RevMan 5 software. Primary outcomes of interest were favorable functional outcomes (modified Rankin Scale score 0–2) and mortality 90 days after stroke.

Thirteen studies (n = 6,198 patients) were identified fulfilling our research question. Thrombus migration was significantly associated with favourable neurological outcomes (mRS 0–2) at 90 days (OR = 1.43; P = 0.025). TM showed no significant impact on other outcomes, including 90-day mortality (OR = 0.86; P = 0.15), symptomatic intracranial hemorrhage (sICH) (OR = 1.12; P = 0.54), any ICH (OR = 1.25; P = 0.4), NIHSS change at discharge (MD = 0.36; P = 0.18) and successful reperfusion rates (TICI 2b–3) (OR = 0.69; P = 0.0686).

Thrombus migration during mechanical thrombectomy was associated with better 90-day functional outcomes. Although thrombus migration might affect complete revasculrization, it may offer clinical benefits by restoring blood flow to larger brain territories.

The online version contains supplementary material available at 10.1007/s00415-025-13609-9.