Management and prognosis of acute extracranial internal carotid artery occlusion

Long-Term Clinical Outcomes After Cerebral Revascularization in Moyamoya Disease With Extracranial Internal Carotid Artery Occlusion

OBJECTIVE

The aim of this study is to evaluate the efficacy of cerebral revascularization for Moyamoya disease (MMD) with extracranial internal carotid artery occlusion (ICAO).

METHODS

This study retrospectively analyzed 37 patients diagnosed with MMD with extracranial ICAO who underwent cerebral revascularization surgery. We conducted propensity score matching for MMD patients without extracranial ICAO from database of 932 MMD patients. Outcome data, recurrent strokes, and modified Rankin Scale were collected during follow-up.

RESULTS

A total of 37 MMD patients with extracranial ICAO were included in the study. The average follow-up time of MMD patients with extracranial ICAO included in the study was 74 months. During the follow-up period, there were 15 hemispheres recurred stroke events. All hemispheres underwent surgery, and the follow-up modified Rankin Scale score was significantly reduced (P < 0.001). Kaplan-Meier analysis showed no significant statistical difference in stroke events among the indirect bypass, direct bypass, and combined bypass groups (P = 0.131). After propensity matching, 48 hemispheres of MMD patients without extracranial ICAO were identified from a review of 932 MMD patients. There was no significant statistical difference in stroke events between the MMD patients with extracranial ICAO group and the MMD group (P = 0.271).

CONCLUSIONS

Cerebral revascularization can prevent recurrent ischemic and hemorrhagic stroke events for MMD patients with extracranial ICAO. There was no difference on long-term clinical outcomes after combined bypass, direct bypass, and indirect bypass surgery. The cerebral revascularization has similar effect on the MMD patients with extracranial ICAO and MMD patients without extracranial ICAO.

Cerebral Angiography and Neurobehavioral Patterns in a Non-human Primate Middle Cerebral Artery Occlusion Model

BACKGROUND/AIM

Ischemic stroke is a major health concern globally and developing reliable animal models is crucial for understanding its pathophysiology. This study evaluated the relationship between cerebral angiographic findings and neurologic dysfunction in an acute non-human primate thromboembolic stroke model and determined the minimum clot length for suitable middle cerebral artery (MCA) occlusion.

MATERIALS AND METHODS

A thromboembolic stroke model was developed by injecting autologous blood clots (length: 1, 2, 3, 4, 5, and 10 cm, n=1 to 3, 14 monkeys in total) into the internal carotid artery of male cynomolgus monkeys. Digital subtraction angiography (DSA) and neurologic deficit observation were performed pre-; immediately after (DSA only); and 1, 3, 6, and 24 h after embolization, and the relationship between clot length, neurologic deficits, and cerebral infarction was assessed.

RESULTS

DSA confirmed MCA occlusion in all animals after the clot injection. Recanalization of the MCA was observed within 6 h post-embolization in animals with shorter clots (≤3 cm). Neurologic deficits were evident in animals with MCA occlusion and correlated with the clot length. Larger clots (≥5 cm) led to permanent MCA occlusion, significant neurologic deficits, and extensive cerebral infarction. Histopathological examination revealed ischemic damage in brain regions corresponding to the infarcted areas.

CONCLUSION

Clot length is critical in determining the extent of neurologic dysfunction and cerebral infarction, with larger clots producing more severe outcomes. Furthermore, the minimum clot length required for model creation is 5 cm.

Development of a Novel Statistical Model for Predicting Clinical Outcomes in Stroke Patients With Tandem Occlusions After Endovascular Therapy

BACKGROUND

Tandem occlusions are intracranial large vessel occlusions (LVOs) with a concomitant ipsilateral extracranial internal carotid artery occlusion and can cause more severe stroke symptoms.

AIM

To develop a simple, rigorously cross-validated novel tool to predict clinical outcomes following tandem occlusion in patients with acute LVO stroke, based on data that are easily available to clinicians. To have used machine learning approaches to utilize the available information from clinical and angiographic data to make predictive models able to distinguish between mortality versus survival and good (modified Rankin Scale (mRS) ≤ 2) versus unfavorable neurological outcomes (mRs ≥ 3) Materials and methods: Retrospective data from 87 consecutive patients with anterior circulation stroke and tandem occlusions who underwent mechanical thrombectomy and stenting between December 2009 and January 2020 were analyzed. Patients were stratified into three groups based on the location of their LVO, and these groups were compared using statistical tests. Predictive models were built and cross-validated 1000 times to estimate their predictive power, measured by accuracy and area under the receiver operating curve (AUROC).

RESULTS

For distinguishing good outcome (mRS ≤ 2) versus poor outcome (mRS ≥ 3), the model comprised age, initial National Institute of Health Stroke Scale (NIHSS) score, Alberta Stroke Program Early CT Score (ASPECTS), NIHSS at 24 hours, NIHSS at discharge and intracranial haemorrhage and yielded an accuracy of 83% and the AUROC of 0.91. For mortality prediction, the model comprised age, initial NIHSS, intravenous thrombolysis, NIHSS at 24 hours and NIHSS at discharge and yielded an accuracy of 91% and an AUROC of 0.94.

CONCLUSIONS

Models developed exhibit strong predictive performance and can distinguish between both the instances of survival versus mortality and good versus poor outcome with an aim to support clinicians in deciding on optimal management for these complex patients. The developed model will help identify those at risk of poorer outcomes and the prospective better selection of patients with acute ischaemic large vessel stroke secondary to tandem occlusions.

Combined Aspiration and Stent Retriever Thrombectomy for Distal Carotid Artery Occlusion Using Balloon Guide versus Non-Balloon Guide Catheter

Background: The introduction of endovascular thrombectomy dramatically changed acute stroke management and became the standard treatment. Balloon guide catheters provide flow arrest during the clot retrieval process and have several advantages.This study aimed to compare balloon guide catheters (BGCs) versus non-balloon guide catheters (NBGCs) as a part of a combined treatment modality in patients presenting with acute ischemic stroke. Methods: This retrospective study included n = 65 patients who underwent a combined endovascular stroke treatment for distal internal carotid artery (ICA) occlusion. Patients underwent aspiration and stent retriever thrombectomy with the use of BGCs (Group 1, n = 27) or NBGCs (Group 2, n = 38). Results: The groups were compared for outcomes: the National Institutes of Health Stroke Scale (NIHSSS) score change, successful recanalization, good functional outcome at three months, and in-hospital mortality. Conclusion: The two groups didn't differ in terms of the NIHSS score change compared to baseline (p > 0.05). Moreover, there were no significant differences between the two groups in terms of the successful recanalization rate, three-month favorable functional outcome rate, and in-hospital mortality (p = 0.292, p = 0.952, p = 0.178), respectively. Further prospective studies with a larger number of patients and better methodology are warranted.

Urgent Endarterectomy for Symptomatic Carotid Occlusion is Associated with a High Mortality

OBJECTIVE

Interventions for carotid occlusions are infrequently undertaken and the outcomes are poorly defined. We sought to study patients undergoing urgent carotid revascularization for symptomatic occlusions.

METHODS

The Society for Vascular Surgery Vascular Quality Initiative database was queried from 2003 to 2020 to identify patients with carotid occlusions undergoing carotid endarterectomy (CEA). Only symptomatic patients undergoing urgent interventions within 24 hours of presentation were included. Patients were identified based on CT and MRI imaging. This cohort was compared to symptomatic patients undergoing urgent intervention for severe stenosis (≥80%). Primary endpoints were perioperative stroke, death, myocardial infarction (MI) and composite outcomes as defined by the SVS reporting guidelines. Patient characteristics were analyzed to determine predictors of perioperative mortality and neurological events.

RESULTS

390 patients who underwent urgent CEA for symptomatic occlusions were identified. The mean age was 67.4±10.2 years (range 39 to 90 years). The cohort was predominantly male (60%) with associated risk factors for cerebrovascular disease, including hypertension (87.4%), diabetes (34.4%), coronary artery disease (21.6%) and current smoking (38.7%). This population had high utilization of medications including statin (78.6%), P2Y₁₂ inhibitor (32.0%), aspirin (77.9%) and renin-angiotensin inhibitor (43.7%) preoperatively. When compared to patients undergoing urgent endarterectomy for severe stenosis (≥80%), those with symptomatic occlusion were well matched with regards to risk factors, but the severe stenosis cohort appeared better medically managed and less likely to present with cortical stroke symptoms. Perioperative outcomes were significantly worse for the carotid occlusion cohort, primarily driven by higher perioperative mortality (2.8% vs 0.9%, P<.001). The composite endpoint of stroke/death/MI was also significantly worse in the occlusion cohort (7.7% vs 4.9%, P=.014). On multivariate analysis, carotid occlusion was associated with increased mortality (OR, 3.028; 95% CI, 1.362-6.730; P=.007) and composite outcome of stroke, death, or MI (OR, 1.790; 95% CI, 1.135-2.822, P=.012).

CONCLUSIONS

Revascularization for symptomatic carotid occlusion constitutes approximately 2% of carotid interventions captured in the VQI, affirming the rarity of this undertaking. These patients have acceptable rates of perioperative neurologic events but are at an elevated risk of overall perioperative adverse events, primarily driven by higher mortality, compared to those with severe stenosis. Carotid occlusion appears to be the most significant risk factor for the composite endpoint of perioperative stroke, death, or MI. While intervention for a symptomatic carotid occlusion may be performed with acceptable rate of perioperative complications, judicious patient selection is warranted in this high-risk cohort.

Delayed revascularization in acute ischemic stroke patients

Stroke shares a significant burden of global mortality and disability. A significant decline in the quality of life is attributed to the so-called post-stroke cognitive impairment including mild to severe cognitive alterations, dementia, and functional disability. Currently, only two clinical interventions including pharmacological and mechanical thrombolysis are advised for successful revascularization of the occluded vessel. However, their therapeutic effect is limited to the acute phase of stroke onset only. This often results in the exclusion of a significant number of patients who are unable to reach within the therapeutic window. Advances in neuroimaging technologies have allowed better assessment of salvageable penumbra and occluded vessel status. Improvement in diagnostic tools and the advent of intravascular interventional devices such as stent retrievers have expanded the potential revascularization window. Clinical studies have demonstrated positive outcomes of delayed revascularization beyond the recommended therapeutic window. This review will discuss the current understanding of ischemic stroke, the latest revascularization doctrine, and evidence from clinical studies regarding effective delayed revascularization in ischemic stroke.

Diagnosis and treatment of acute isolated proximal internal carotid artery occlusions: a narrative review

The clinical manifestations of proximal (extracranial) internal carotid artery occlusions (pICAOs) may range from asymptomatic to acute, large, and devastating ischemic strokes. The etiology and pathophysiology of the occlusion, intracranial collateral status and patient's premorbid status are among the factors determining the clinical presentation and outcome of pICAOs. Rapid and accurate diagnosis is crucial and may be assisted by the combination of carotid and transcranial duplex sonography, or a computed tomography/magnetic resonance angiography (CTA/MRA). It should be noted that with either imaging modalities, the discrimination of a pseudo-occlusion of the extracranial internal carotid artery (ICA) from a true pICAO may not be straightforward. In the absence of randomized data, the management of acute, symptomatic pICAOs remains individualized and relies largely on expert opinion. Administration of intravenous thrombolysis is reasonable and probably beneficial in the settings of acute ischemic stroke with early presentation. Unfortunately, rates of recanalization are rather low and acute interventional reperfusion therapies emerge as a potentially powerful therapeutic option for patients with persistent and severe symptoms. However, none of the pivotal clinical trials on mechanical thrombectomy for acute ischemic stroke randomized patients with isolated extracranial large vessel occlusions. On the contrary, several lines of evidence from non-randomized studies have shown that acute carotid endarterectomy, or endovascular thrombectomy/stenting of the ICA are feasible and safe, and pοtentially beneficial. The heterogeneity in the pathophysiology and clinical presentation of acute pICAOs renders patient selection for an acute interventional treatment a complicated decision-making process. The present narrative review will outline the pathophysiology, clinical presentation, diagnostic challenges, and possible treatment options for pICAOs.

When Can an Emergency CTA Be Dispensed with for TIA Patients?

Background: Transient ischemic attacks (TIAs) and minor strokes are often precursors of a major stroke. Therefore, diagnostic work-up of the TIA is essential to reduce the patient’s risk of further ischemic events. Purpose: With the help of this retrospective study, we aim to determine for which TIA patients a CT angiography (CTA) is not immediately necessary in order to reduce radiation exposure and nephrotoxicity. Material and Methods: Clinical and imaging data from patients who presented as an emergency case with a suspected diagnosis of TIA at a teaching hospital between January 2016 and December 2021 were evaluated. The included 1526 patients were divided into two groups—group 1, with major pathologic vascular findings in the CTA, and group 2, with minor vascular pathologies. Results: Out of 1821 patients with suspected TIA on admission, 1526 met the inclusion criteria. In total, 336 (22%) had major vascular pathologies on CTA, and 1190 (78%) were unremarkable. The majority of patients with major vascular pathologies were male and had a history of arterial hypertension, coronary heart disease, myocardial infarction, ischemic stroke, TIA, atherosclerotic peripheral vascular disease, smoking, antiplatelet medication, had a lower duration of TIA symptoms, and had lower ABCD2 scores. Conclusions: We were able to demonstrate a direct correlation between major CTA pathologies and a history of smoking, age, hyperlipidemia, history of peripheral arterial disease, and a history of stroke and TIA. We were able to prove that the ABCD2 score is even reciprocal to CTA pathology. This means that TIA patients without described risk factors do not immediately require a CTA and could be clarified in the course of treatment with ultrasound or MRI.

Coexistence of external carotid artery embolus and internal carotid artery occlusion in acute ischemic stroke: An indicator of cardioembolic etiology?

OBJECTIVES

This study aims to evaluate whether the presence of an external carotid artery embolism accompanying internal carotid artery occlusion may contribute to identifying the etiology of internal carotid artery occlusion in the early period.

MATERIAL AND METHODS

The presence of external carotid artery embolism was evaluated in 117 patients who were adjudicated for internal carotid artery occlusion based on digital subtraction angiography images.

RESULTS

Embolus in the external carotid artery was detected in 8 (6.8%) of the 117 patients with internal carotid artery occlusion (7 (87.5%) patients were found to have tandem and 1 (12.5%) patient had carotid T occlusion). In all of these patients, the thrombus was of embolic origin. Evaluation of the etiology revealed cardioembolic etiology in 4 patients and dissection in 1 patient, and the cause could not be determined in the remaining 3 patients. Patients with external carotid artery embolism accompanying an internal carotid artery occlusion had significantly higher The National Institutes of Health Stroke Scale scores at admission and significantly lower recanalization success compared to those without external carotid artery embolism (p = 0.009, p = 0.01). In the comparison of prognosis, poorer prognosis was observed in those with external carotid artery embolism, although without a statistically significant difference (p = 0.07).

CONCLUSIONS

This study observed that the etiology was mostly embolic in patients with external carotid artery embolism accompanying an internal carotid artery occlusion, most of whom were found to have tandem embolic occlusion, and cardiac origin appeared to be the prominent etiology of stroke.

Mechanical Thrombectomy for Bihemispheric Infarction Caused by Acute Unilateral Internal Carotid Artery Occlusion in a Patient with Contralateral Chronic Carotid Occlusion: A Case Report

Objective

We report a patient with acute bihemispheric infarction who underwent mechanical thrombectomy.

Case Presentation

A 76-year-old man suddenly developed coma and quadriplegia. Brain MRI and MRA revealed acute bihemispheric infarction due to occlusions of both the internal carotid arteries (ICAs). According to the DSA findings, we considered the left ICA as chronic occlusion and the right as acute. Mechanical thrombectomy for the right ICA occlusion was performed. Total recanalization was achieved using a stent retriever 181 minutes after onset. The left hemisphere was perfused by cross circulation through the anterior communicating artery, but the symptoms did not improve. MRI the day after thrombectomy showed extensive bihemispheric infarction. Recanalization for the bilateral hemispheres was maintained, although the left ICA remained occluded. He died 2 months later due to gastrointestinal bleeding.

Conclusion

Acute bihemispheric infarction due to occlusions of both ICAs is a rare entity. The symptoms are very severe and the therapeutic time window is extremely short because of absent collateral pathways. We should consider pre-existing carotid occlusive disease, determine whether the occlusions are acute or chronic, and perform prompt therapy. Further investigation is warranted to obtain a better outcome.