Endovascular Recanalization for Acute Internal Carotid Artery Terminus Occlusion: A Subgroup Analysis From the Direct-MT Trial

Prognostic analysis of endovascular mechanical thrombectomy in stroke patients with acute internal carotid artery obstruction based on circle of Willis variation

Objective

Endovascular mechanical thrombectomy (EVMT) is widely employed in patients with acute intracranial carotid artery occlusion (AIICAO). This study aimed to predict the outcomes of EVMT following AIICAO by utilizing anatomic classification of the circle of Willis and its relative position to the thrombus.

Methods

In this study, we retrospectively analyzed a cohort of 108 patients with AIICAO who underwent endovascular mechanical thrombectomy (EVMT) at Shaoxing People's Hospital. Based on variations in the circle of Willis, as well as the size and location of the thrombus occluding the middle cerebral artery (MCA), anterior cerebral artery (ACA), and posterior cerebral artery (PCA), we classified AIICAO into four grades using digital subtraction angiography (DSA). EVMT was initiated upon admission, and baseline data including demographic characteristics, vascular risk factors, angiographic features, initial National Institutes of Health Stroke Scale (NIHSS) scores, Alberta Stroke Program Early CT Score (ASPECT), and etiology classification were compared across these four grades. The prognosis and mortality rates at 90 days post-stroke were evaluated for the different grades and within each grade, patients were further categorized into two subtypes based on vascular compensation and occluded vessels.

Results

Significant differences were observed among the four grades of Willis compensation concerning etiologic classification (p = 0.008), postoperative modified treatment in cerebral ischemia (mTICI, p = 0.017), postoperative symptomatic intracranial hemorrhage (sICH, p = 0.007), NIHSS score at admission (p = 0.001), and favorable outcomes at 90 days (modified Rankin Score 0-2) (p = 0.003). The mortality rate at 90 days exhibited a significant difference across the four grades of Willis compensation (p = 0.05). However, prognosis did not reveal any significant differences among the various subtypes within the same grade (p > 0.05).

Conclusion

The assessment of the degree of Willis compensation can be improved by evaluating the integrity of the circle of Willis, as well as the size and location of the clot in cases of isolated internal carotid artery occlusion (iICAo). This approach provides valuable prognostic indicators and important insights for the pre-selection of patients prior to endovascular mechanical thrombectomy (EVMT).

Futile recanalization after endovascular treatment in acute ischemic stroke with large ischemic core

BACKGROUND

Endovascular therapy (EVT) is the treatment of choice for acute ischemic stroke (AIS) with large vessel occlusion. However, in many patients, successful EVT recanalization does not correspond to a clinical improvement, called futile recanalization (FR). We aimed to identify stroke risk factors and patient characteristics associated with FR in AIS with large core infarct (LCI).

METHODS

A total of 137 patients with AIS with LCI treated by EVT at a single stroke center were retrospectively included from January 2016 to June 2023. LCI was defined by Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECT) < 6. Patient age, sex, modified Rankin Scale (mRS), National Institutes of Health Stroke Scale (NIHSS), time to treatment, risk factors, and radiologic findings were collected, and potential associations with FR were analyzed. FR was defined as successful reperfusion with modified Thrombolysis in Cerebral Infarction (mTICI) ≥ 2b but without functional independence at 90 days (mRS ≥ 3). A multivariate logistic regression analysis was conducted on the clinical characteristics of patients, based on the presence or absence of FR, and the factors influencing FR.

RESULTS

Of 137 patients, 120 showed successful recanalization (mTICI ≥ 2b). All patients were divided into FR (n = 80) and no FR (n = 40) groups. Older age (odds ratio [OR] 1.052, 95% confidence interval [CI] 1.002-1.105; p = 0.041), the higher the initial NIHSS score (OR 1.181, 95% CI 1.037-1.344; p = 0.012), and prior intravenous plasminogen activator (OR 0.310, 95% CI 0.118-0.813, p = 0.017) were independent influencing factors of FR.

CONCLUSIONS

The older age, the higher the initial NIHSS, and not receiving intravenous plasminogen activator were independently associated with FR in AIS with LCI. These factors could identify poor responders to EVT recanalization.

Introducing the Futile Recanalization Prediction Score (FRPS): A Novel Approach to Predict and Mitigate Ineffective Recanalization after Endovascular Treatment of Acute Ischemic Stroke

Objective: This study aims to develop and validate the Futile Recanalization Prediction Score (FRPS), a novel tool designed to predict the severity risk of FR and aid in pre- and post-EVT risk assessments. Methods: The FRPS was developed using a rigorous process involving the selection of predictor variables based on clinical relevance and potential impact. Initial equations were derived from previous meta-analyses and refined using various statistical techniques. We employed machine learning algorithms, specifically random forest regression, to capture nonlinear relationships and enhance model performance. Cross-validation with five folds was used to assess generalizability and model fit. Results: The final FRPS model included variables such as age, sex, atrial fibrillation (AF), hypertension (HTN), diabetes mellitus (DM), hyperlipidemia, cognitive impairment, pre-stroke modified Rankin Scale (mRS), systolic blood pressure (SBP), onset-to-puncture time, sICH, and NIHSS score. The random forest model achieved a mean R-squared value of approximately 0.992. Severity ranges for FRPS scores were defined as mild (FRPS < 66), moderate (FRPS 66-80), and severe (FRPS > 80). Conclusions: The FRPS provides valuable insights for treatment planning and patient management by predicting the severity risk of FR. This tool may improve the identification of candidates most likely to benefit from EVT and enhance prognostic accuracy post-EVT. Further clinical validation in diverse settings is warranted to assess its effectiveness and reliability.

Combined Technique for Internal Carotid Artery Terminus or Middle Cerebral Artery Occlusions in the ASTER2 Trial

BACKGROUND

The aim of this study was to report the results of a subgroup analysis of the ASTER2 trial (Effect of Thrombectomy With Combined Contact Aspiration and Stent Retriever vs Stent Retriever Alone on Revascularization in Patients With Acute Ischemic Stroke and Large Vessel Occlusion) comparing the safety and efficacy of the combined technique (CoT) and stent retriever as a first-line approach in internal carotid artery (ICA) terminus±M1-middle cerebral artery (M1-MCA) and isolated M1-MCA occlusions.

METHODS

Patients enrolled in the ASTER2 trial with ICA terminus±M1-MCA and isolated M1-MCA occlusions were included in this subgroup analysis. The effect of first-line CoT versus stent retriever according to the occlusion site was assessed on angiographic (first-pass effect, expanded Treatment in Cerebral Infarction score ≥2b50, and expanded Treatment in Cerebral Infarction score ≥2c grades at the end of the first-line strategy and at the end of the procedure) and clinicoradiological outcomes (24-hour National Institutes of Health Stroke Scale, ECASS-III [European Cooperative Acute Stroke Study] grades, and 3-month modified Rankin Scale).

RESULTS

Three hundred sixty-two patients were included in the postsubgroup analysis according to the occlusion site: 299 were treated for isolated M1-MCA occlusion (150 with first-line CoT) and 63 were treated for ICA terminus±M1-MCA occlusion (30 with first-line CoT). Expanded Treatment in Cerebral Infarction score ≥2b50 (odds ratio, 11.83 [95% CI, 2.32-60.12]) and expanded Treatment in Cerebral Infarction score ≥2c (odds ratio, 4.09 [95% CI, 1.39-11.94]) were significantly higher in first-line CoT compared with first-line stent retriever in patients with ICA terminus±M1-MCA occlusion but not in patients with isolated M1-MCA.

CONCLUSIONS

First-line CoT was associated with higher reperfusion grades in patients with ICA terminus±M1-MCA at the end of the procedure.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03290885.

The relationship between occlusion patterns and outcomes after thrombectomy in patients with acute internal carotid artery occlusion

BACKGROUND AND PURPOSES

Ischemic stroke caused by acute internal carotid artery occlusions (AICO) is usually associated with high disability and mortality. We aimed to investigate whether occlusion patterns significantly influence clinical outcome in patients receiving endovascular thrombectomy (EVT).

PATIENTS AND METHODS

We performed a retrospective analysis of databases from two comprehensive stroke centers and consecutively investigated patients who had underwent EVT. AICO was defined as acute internal carotid artery occlusions (cervical segment to terminal segment). The clinical characteristics, intervention parameters, and prognosis data were collected. Leptomeningeal collaterals (LMC) were assessed with the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale (ASITN/SIRs), graded on a 5-point scale. The occlusion patterns based on Willisian collaterals were categorized into I-type, L-type, and T-type by contralateral carotid artery injections at digital subtraction angiography. Multivariate regression models were applied to evaluate the relationship between occlusion patterns and the prognosis of patients at 90 days after stroke.

RESULTS

A total of 213 patients were included in the study. Of those,142 (66.7%) achieved successful reperfusion and 64 (30.0%) achieved favorable outcomes at 90 days. Overall, 26 (12.2%), 117 (54.9%), and 70 (32.9%) cases respectively suffered from I-type, L-type, and T-type occlusion. In addition, patients with I-type occlusions had a higher percentage of complete LMC compared with L-type or T-type occlusions (88.5% versus 30.8% versus 27.1%, P< 0.0167). In multivariable logistic regression, we found T-type occlusion was no longer an independent predictor of poor functional outcomes in AICO after adjusting LMC (T versus I, OR, 2.555, 95%CI: 0.717-9.103, P = 0.148; L versus I, OR, 0.815, 95%CI: 0.258-2.574, P = 0.727).

CONCLUSIONS

For ACIO, occlusion patterns are still a topic that needs attention. Furthermore, compensatory LMC may affect the association between occlusion patterns and functional prognosis in AICO. Occlusion patterns and LMC status distinguish the nature and impact of AICO on expected EVT and subsequent clinical outcomes.