Thrombectomy versus conservative treatment for medium vessel occlusion ineligible for intravenous thrombolysis:...

Neutral results from randomised trials of endovascular thrombectomy (EVT) in medium vessel occlusion (MeVO) may reflect treatment heterogeneity, particularly high intravenous thrombolysis (IVT) use in medical management arms. We aimed to evaluate the efficacy of EVT compared with conservative treatment in IVT-ineligible MeVO patients.

Consecutive IVT-ineligible MeVO patients from a single centre were retrospectively included and grouped according to the treatment received. The primary outcome was favourable outcome (90-day modified Rankin Scale score: 0-1). Inverse probability weighting (IPW) using propensity scores was applied to adjust for baseline differences.

A total of 226 IVT-ineligible MeVO patients were included, with 54 receiving EVT and 172 receiving conservative treatment. After IPW adjustment, the effective sample sizes were 97 in the EVT group and 145 in the conservative group, with baseline covariates well balanced between groups (standardised mean differences <0.1 for all variables). No significant differences were observed in rates of favourable outcome (54.6% vs 51.0%, P=0.675) or functional independence (68.0% vs. 67.6%, P=0.998) between groups. Symptomatic intracranial haemorrhage occurred more frequently in the EVT group (8.2% vs 0%, P=0.002). In the subgroup analysis, a potential association between EVT and favourable outcome was observed among patients with a baseline National Institutes of Health Stroke Scale (NIHSS) score ≥6 (adjusted odds ratio [aOR]: 1.83; 95% confidence interval [CI]: 1.17-2.76).

In IVT-ineligible patients with MeVO, there was no significant difference in functional outcomes between EVT and conservative management groups. In subgroup analyses, EVT showed a potential benefit in patients with a baseline NIHSS score ≥6.