Direct endovascular treatment may be more appropriate for patients with good collateral circulation: a retrospective case-control study.

Background: Recent studies have shown that endovascular treatment (EVT) alone is noninferior to the combination of intravenous thrombolysis and EVT (IVT + EVT) in patients with acute ischemic stroke due to large-vessel occlusion (AIS-LVO) in the anterior cerebral circulation. However, some studies report conflicting results suggesting that the benefits of IVT may be limited to specific subgroups. Previous research has established a strong correlation between collateral status and prognosis in patients treated with IVT or EVT. The primary aim of this study was to investigate the impact of collateral status on clinical outcomes in patients receiving EVT alone or IVT + EVT. Methods: We retrospectively collected data from 238 consecutive patients who were diagnosed with AIS-LVO and underwent EVT or IVT + EVT from January 2019 to January 2023. Patients were divided into two groups, based on whether they received IVT prior to EVT. Multivariable ordinal logistic regression with an interaction term was used to assess the impact of collateral circulation on treatment outcomes, including 90-day modified Rankin Scale (mRS) scores, success rate of recanalization, incidence of intracerebral hemorrhage, mortality, embolus migration, and the rate of achieving a modified thrombolysis in cerebral infarction (mTICI) score of 3. To adjust the common odds ratio (OR), we included variables such as gender, age, baseline National Institutes of Health Stroke Scale (NIHSS) score, Alberta Stroke Program Early Computed Tomography Score (ASPECTS), and onset-to-puncture time. Results: Overall, patients with adequate collateral circulation, defined as a regional leptomeningeal collateral score of 17-20 points, demonstrated more favorable 90-day outcomes, including lower mRS score, higher recanalization success rate, and lower rates of intracerebral hemorrhage, mortality, embolus migration, along with higher likelihood of achieving mTICI 3 score. However, the impact of collateral circulation differed between the two groups. In the EVT group, improved collateral circulation was significantly associated with better outcomes [OR: 8.381, 95% confidence interval (CI): 2.120-46.695, P=0.006]. In the IVT + EVT group, improved collateral circulation was linked to better outcomes (OR: 3.157, 95% CI: 1.618-6.541, P=0.001), it was additionally associated with a higher mortality rate (OR: 0.334, 95% CI: 0.145-0.725, P=0.007), increased incidence of embolus escape (OR: 0.359, 95% CI: 0.130-0.894, P=0.033), and a reduced likelihood of mTICI 3 recanalization (OR: 0.460, 95% CI: 0.244-0.844, P=0.014). Conclusions: Better collateral circulation is associated with favorable 90-day outcomes in both EVT group and IVT + EVT group. However, in the IVT + EVT group better collateral circulation was also linked to a higher rate of mortality, increased incidence of embolus escape, and lower rate of mTICI 3 recanalization. This may suggest that AIS-LVO patients with better collateral circulation could benefit more from EVT alone. Future studies are warranted to confirm these findings.