Valor de la escala ASPECTS de circulación posterior y del índice puente-mesencéfalo en imágenes de TC sin contraste y angiografía por TC en pacientes con oclusiones de la arteria basilar recanalizados tras trombectomía mecánica

Influencing factors of futile recanalization after endovascular therapy for cerebral infarction with posterior circulation occlusion of large vessels: a retrospective study

BACKGROUND

The optimal treatment for cerebral infarction caused by posterior circulation occlusion of large vessels has not yet been determined. Intravascular interventional therapy is an important treatment for cerebral infarction with posterior circulation occlusion of large vessels. However, endovascular therapy (EVT) of some posterior circulation cerebrovascular is ineffective and eventually become futile recanalization. Therefore, we performed a retrospective study to explore the factors influencing futile recanalization after EVT in patients with posterior circulation large-vessel occlusion.

METHODS

Eighty-six patients with acute cerebral infarction and posterior circulation large vessel occlusion after intravascular intervention were divided into two groups according to their modified Rankin scale (mRS) scores after 3 months: group 1, mRS scores less than or equal to 3 (the effective recanalization group); group 2, mRS scores greater than 3 (the ineffective recanalization group). The basic clinical data, imaging index scores, time from onset to recanalization, and operation time between the two groups were compared and analyzed. Logistic regression was used to analyze the factors influencing indicators of good prognosis, and the ROC curve and Youden index were used to determine the best cutoff value.

RESULTS

Between the two groups, there were significant differences in the posterior circulation CT angiography (pc-CTA) scores, GCS scores, pontine midbrain index scores, time from discovery to recanalization, operation time, NIHSS score and incidence of gastrointestinal bleeding. The logistic regression revealed that the NIHSS score and time from discovery to recanalization were associated with good prognoses.

CONCLUSION

NIHSS score and recanalization time were independent influencing factors of ineffective recanalization of cerebral infarctions caused by posterior circulation occlusion. EVT is relatively effective for cerebral infarction caused by posterior circulation occlusion when the NIHSS score is less than or equal to 16 and the time from onset to recanalization is less than or equal to 570 min.

Mechanical thrombectomy for vertebral and basilar artery occlusions: An institutional experience with 17 patients

Acute ischemic stroke of the posterior circulation as a result of vertebrobasilar artery occlusions is often associated with severe morbidity and mortality rates. Vertebrobasilar artery occlusion retrieval via mechanical thrombectomy (MT) is a novel treatment modality for occlusive strokes. Nevertheless, factors associated with positive outcomes have not yet been adequately investigated. Thus, the present study focused on factors associated with good prognosis following this type of treatment. The present study retrospectively analyzed a series of 17 patients with acute vertebral artery occlusions (VAOs) and basilar artery occlusions (BAOs) treated with MT. In all patients, information such as sex and age, time from admission to the onset of femoral artery access, the number of thrombi removed, the time of femoral artery access to recanalization, pre- and post-operative National Institutes of Health Stroke Scale (NIHSS) scores, pre- and post-operative thrombolysis in cerebral infarction, as well as modified Rankin scale scores were documented and analyzed. The analysis comprised of 11 patients with BAOs and 6 patients with VAOs. A recanalization rate of 70.6% was achieved with an overall good functional outcome of 58.8% at 90 days. Observationally, there was a notable improvement in outcomes when comparing the NIHSS prior to surgery with NIHSS at 1 week after the surgery. A lower NIHSS score prior to MT may be a good prognostic factor. An average time of ~5.5 h from patient admittance to recanalization with a 70.6% recanalization rate with an overall good functional outcome of 58.8% at 90 days suggested that, patients for whom the surgeries were performed within 5 h of admittance may still have hope for recanalization compared to an initial 1.5-h average time for recanalization.

Imaging-based outcome prediction in posterior circulation stroke

BACKGROUND AND PURPOSE

We developed a machine learning model to allow early functional outcome prediction for patients presenting with posterior circulation (pc)-stroke based on CT-imaging and clinical data at admission. The proposed algorithm utilizes quantitative information from automated multidimensional assessments of posterior circulation Acute Stroke Prognosis Early CT-Score (pc-ASPECTS) regions. Discriminatory power was compared to predictions based on conventional pc-ASPECTS ratings.

METHODS

We retrospectively analyzed non-contrast CTs and clinical data of 172 pc-stroke patients. 90 days outcome was dichotomized into good and poor using modified Rankin Scale (mRS) cut-offs. Predictive performance was assessed for outcome differentiation at mRS 2, 3, 4 and survival prediction (mRS ≤ 5) using random forest algorithms. Results were compared to conventional pc-ASPECTS and clinical parameters. Models were evaluated in a nested fivefold cross-validation approach.

RESULTS

Receiver operating characteristic areas under the curves (ROC-AUCs) of the test sets using conventionally rated pc-ASPECTS reached 0.63 for mRS ≤ 4 to 0.68 for mRS ≤ 5 and 0.73 for mRS ≤ 5 to 0.85 for mRS ≤ 2 if clinical data were considered. Pure imaging-based machine learning classifier ROC-AUCs were lowest for mRS ≤ 4 (0.81) and highest for mRS ≤ 5 (0.87). The combined clinical data and machine learning-based model had the highest predictive performance with ROC-AUCs reaching 0.90 for mRS ≤ 2.

CONCLUSION

Machine learning-based evaluation of pc-ASPECTS regions predicts functional outcome of pc-stroke patients with higher accuracy than conventional assessments. This could optimize triage for additional diagnostics and allocation of best possible medical care and might allow required arrangements of the social environment at an early point of time.

Posterior Circulation Stroke: Coma (More Than Time) is Brain

BACKGROUND AND PURPOSE

Contrary to anterior circulation, the legitimacy of endovascular treatment in posterior circulation stroke is still being questioned. Finding reliable prognostic factors and determining how patient selection should be done has become top priority.

METHODS

Observational and retrospective study from two Portuguese hospitals, including all consecutive patients with posterior circulation occlusions who underwent thrombectomy between January 1st 2015 and December 31st 2019.

RESULTS

Out of a total of 126 patients, the median age was 74 (IQR 61-80) and 39.7% were female. A good clinical outcome (mRS ≤2) was associated with a lower incidence of coma (24,2% vs 66,7%, p < 0,001) and of sudden onset coma (3% vs 18%,=0,04), a lower NIHSS at admission (14 vs 19, p < 0,001), a higher pc-ASPECTS at admission (10 vs 9, p < 0,001) and at 24 h (8 vs 6, p < 0,001) and a higher BATMAN score (7 vs 6, p = 0,017). Differences in the times of symptom-onset-to-recanalization (496 vs 536, p = 0,19) and symptom-onset-to-coma (130 vs 195, p = 0,52) were not remarkable. When excluding NIHSS and pc-ASPECTS at 24 h, coma (p = 0,003; OR=0,22; 95% CI: 0,08-0,59) and the pc-ASPECTS at admission (p = 0,037; OR=1,63; 95% CI: 1,03-2,57) become independent predictors of good outcome.

CONCLUSIONS

In strokes from the posterior circulation, coma, more than time, appears to be an important prognostic factor. The BATMAN and the pc-ASPECTS scores were also associated with clinical outcome and coma.

Acute basilar artery occlusion (BAO): a pictorial review of multimodal imaging findings

Acute basilar artery occlusion (BAO) is an uncommon cause of stroke; however, it constitutes a serious medical emergency and is associated with elevated mortality rates as well as unfavorable functional outcomes. This is especially true when it is not rapidly diagnosed, and the initiation of reperfusion therapies is delayed. Its etiology is mainly embolic or atherosclerotic, and it often presents with non-specific signs and symptoms (e.g., vertigo, cephalalgia, reduced consciousness, or hemiparesis) that can simulate an anterior circulation stroke. Therefore, obtaining imaging studies that include computed tomography (CT), computed tomography angiography (CTA), and diffusion-weighted magnetic resonance imaging (DWI MRI) as part of the diagnostic approach is crucial to make an accurate diagnosis. The main pillar of acute BAO treatment is early recanalization using intravenous thrombolysis, mechanical thrombectomy, or bridging therapy, in which both methods are used. This pictorial essay illustrates the essential role that multimodal imaging plays in the prompt diagnosis, management, and overall outcome of patients with acute BAO.

Brain Imaging Findings and Response to Intravenous Thrombolysis in Posterior Circulation Stroke

INTRODUCTION

Intravenous thrombolysis (IVT) is a standard treatment for both anterior circulation ischaemic stroke (ACIS) and posterior circulation ischaemic stroke (PCIS). Our aim was to evaluate the predictors for a good clinical outcome and intracerebral haemorrhage (ICH) in patients undergoing posterior circulation IVT based on the initially performed CT or MR imaging.

METHODS

The study cohort consisted of 1643 consecutive patients with acute ischaemic stroke (1440 ACIS, 203 PCIS cases) who underwent IVT. ICH was classified according to the European Cooperative Acute Stroke Study (ECASS) I protocol. Clinical outcome was assessed using the modified Rankin scale (mRS). Early ischaemic signs and pre-existing structural signs were assessed.

RESULTS

Good clinical outcomes (mRS 0-1) were noted in 45.3% of patients with PCIS, with a mortality rate of 14.8%. ICH was noted in 8.3%, and a large haemorrhage was found in 2.4% of patients. Some early ischaemic signs and pre-existing structural signs on initial CT/MR imaging correlated significantly with the 90-day clinical outcome.

CONCLUSIONS

Early ischaemic signs and pre-existing structural signs should be considered during the assessment of patients with PCIS eligible for IVT. Tissue hypoattenuation on initial CT scans correlates with an increased risk of death. Similarly to anterior circulation, atrophy on initial MRI may negatively predict good clinical outcome in posterior circulation.

Thrombectomy for Posterior Circulation Stroke: Predictors of Outcomes in a Brazilian Registry

BACKGROUND

Acute basilar artery occlusion is a devastating life-threatening condition. Early recanalization is the therapeutic goal in patients with acute ischemic stroke. Despite the high rates of recanalization achieved with modern devices for basilar occlusions, many patients have had poor clinical outcomes. This study aimed to assess the predictors of good and poor outcomes among patients with basilar artery occlusion treated with thrombectomy.

METHODS

A consecutive registry of 80 patients was included in this retrospective study. The primary end point was to access variables associated with neurologic outcomes defined by a modified Rankin Scale (mRS) score of 0-2, symptomatic intracranial hemorrhage (sICH), and mortality at 3 months follow-up.

RESULTS

Recanalization was achieved in 86.2%, and the sICH rate was 8.7%. A good neurologic outcome (mRS score 0-2) was observed in 26.2% and a moderate outcome (mRS score 0-3) in 32.5% of patients. The mortality was 38.7% at 3 months follow-up.

CONCLUSIONS

After thrombectomy for posterior circulation strokes, young patients, V4-proximal basilar occlusion, (high) baseline posterior circulation Alberta Stroke Program Early CT Score, and complete recanalization were independent predictors of good neurologic outcomes. Failure to recanalize was strongly related to sICH and mortality. In addition, diabetes, atrial fibrillation, and baseline National Institutes of Health Stroke Scale scores ≥10 had an independent association with mortality. This study contributes to the knowledge required to optimize recanalization treatments for posterior circulation strokes and may help to improve future clinical studies.

Neuroimaging of Acute Stroke

Acute stroke is the clinical manifestation of disrupted blood flow or bleeding in the central nervous system. Imaging supports the clinical diagnosis and can aide in acute treatment decision making and guide information on prognosis. Features that are delineated include the parenchyma and the blood vessels. Parenchymal characteristics include early ischemic changes, established infarct and tissue at risk (penumbra), and hemorrhage. Vessel pathology includes arterial and venous steno-occlusive disease and vascular malformations. In the presence of a vessel occlusion, vessel imaging can assess collateral flow. This article outlines the role of neuroimaging as applied to patients presenting with acute stroke.