Extracranial Internal Carotid Artery Occlusion Research Articles

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

ObjectiveThe aim of this study is to evaluate the efficacy of cerebral revascularization for Moyamoya disease (MMD) with extra-cranial internal carotid artery occlusion (ICAO). MethodsThis study retrospectively analyzed 37 patients diagnosed with MMD with extra-cranial ICAO who underwent cerebral revascularization surgery. We conducted propensity score matching for MMD patients without extra-cranial ICAO from database of 932 MMD patients. Outcome data, recurrent strokes and modified Rankin Scale (mRS) were collected during follow-up. ResultsA total of 37 MMD patients with extra-cranial ICAO were included in the study. The average follow-up time of MMD patients with extra-cranial 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 mRS score was significantly reduced (P <0.001). Kaplan-Meier analysis showed no significant statistical difference in stroke events between the indirect bypass (IB), direct bypass (DB), and combined bypass (CB) groups (P = 0.131). After propensity matching, 48 hemispheres of MMD patients without extra-cranial ICAO were identified from a review of 932 MMD patients. There was no significant statistical difference in stroke events between the MMD patients with extra-cranial ICAO group and the MMD group (P = 0.271). ConclusionsCerebral revascularization can prevent recurrent ischemic and hemorrhagic stroke events for MMD patients with extra-cranial ICAO. There was no difference on long-term clinical outcomes after CB, DB, and IB surgery. The cerebral revascularization has similar effect on the MMD patients with extra-cranial ICAO and MMD patients without.

Technique for Recanalization of Sheath Introducer Occlusion due to Captured Thrombus during Mechanical Thrombectomy for Acute Ischemic Stroke: A Technical Note.

Mechanical thrombectomy (MT) is the gold standard treatment for acute ischemic stroke. During these interventions, a thrombus frequently obstructs a guiding catheter. The obstructed guiding catheter should be withdrawn before distal embolism occurs; however, albeit infrequently, the thrombus occludes even a sheath introducer (SI). While conventionally new SI placement is required for continuation of treatment, we propose a viable alternative for recanalization of the occluded SI, termed vacuum-assisted delivery of thrombus (VADT), with a clinical report of our cases. The usefulness of this technique was also evaluated in simulation experiments. The VADT procedure is as follows: 1) insert a peel-away sheath, originally attached to a balloon-guiding catheter (BGC), into the SI to continuously open the hemostatic valve; 2) advance the BGC into the peel-away sheath while applying mechanical aspiration; and 3) remove the peel-away sheath/BGC assembly slowly. In a simulation environment using an artificial thrombus, we repeated the VADT procedure five times and reproducibly achieved SI reopening within only 10-20 seconds. From March 2013 to September 2022, 204 patients were treated with MT at our stroke center and SI occlusion occurred in three patients (1.5%). These events occurred exclusively in patients with extracranial internal carotid artery occlusion. All three patients with SI occlusion underwent successfully thrombus extraction in the SI using the VADT on the first try. The results of clinical experience and simulation experiments strongly support VADT as a reliable option for recanalization of an occluded SI.

Abstract 049: Effect of the ICA Lesion Severity in Outcomes after Endovascular Treatment of Acute Tandem LVO

Introduction Tandem Lesions (TLs) pose unique challenges in the endovascular management of acute ischemic stroke.(1) The absence of anterograde blood flow in the carotid occluded segment may limit the effectiveness of endovascular interventions, resulting in delayed reperfusion or suboptimal recanalization.(2,3) Thus, the presence of unpaired blood flow through the ICA in the context of TLs is believed to exacerbate the extension of ischemic lesions. (4,5) This study compared the clinical and procedural outcomes of patients with TLs and extracranial internal carotid artery occlusion versus those with stenosis. Methods A retrospective analysis was performed on a multicenter cohort of patients with TLs who underwent endovascular treatment. The patients were categorized into two groups: those with extracranial ICA stenosis and those with occlusion. Clinical outcomes, including functional independence, hemorrhagic events, and procedural time metrics including puncture to reperfusion time were assessed. Sensitivity analyses were conducted to evaluate these differences segregating patients according to varying degrees of stenosis, and in pre‐specified subgroups. Results A total of 513 patients with TLs were included in the study. 281 (54.8%) presented with ICA occlusion, and 232 (45.2%) presented stenosis &gt;=70% (Table 1). The comparison between the stenosis and occlusion groups revealed no significant differences in the main outcomes, including mTICI 2c‐3 (47.5% vs. 50.6%, aOR 1.07, 95% CI 0.70‐1.64, p=.751) (Figure 1), mRS 0‐2 at 90 days (43.6% vs. 48.9%, aOR 0.79, 95% CI 0.52‐1.20, p=.271), sICH rates (4.7% vs. 5.6%, aOR 0.72, 95% CI 0.31‐1.71, p=.458), and puncture to reperfusion time (58 [40‐80.5] vs. 52.5 [35.2‐80], ratio 1.04, 95% CI 0.88‐1.23, p=.64). Similar analyses performed comparing different degrees of stenosis and occlusion, and in patients treated with the antegrade approach only, did not show significant differences either. Conclusion Our findings indicate that although more severe degrees of stenosis or occlusion of the ICA prolong the time from puncture to reperfusion, no significant differences in clinical outcomes exist. The clinical implications of these findings need to be further evaluated to fully comprehend the specific needs of patients affected by TLs.

Acute ischemic stroke: The role of emergency carotid endarterectomy in isolated extracranial internal carotid artery occlusion.

The treatment of choice for acute and isolated extracranial internal carotid artery (eICA) occlusion remains, to date, controversial. Although intravenous thrombolysis is recommended, its effectiveness is generally low. This retrospective study aims to assess the clinical outcome and the role of CT perfusion in symptomatic patients who underwent carotid endarterectomy (CEA) for acute occlusion of the eICA. All the 21 patients presented with stroke-in-evolution, complete patency of intracranial circulation, no evidence of hemorrhagic transformation at CT and a minimum ASPECTS of 6. Clinical improvement was assessed by evaluating the variation of NIHSS and the mRS. We investigated the relationship between NIHSS and the timing of the surgery, the ASPECT score, and the volume of ischemic penumbra at CT perfusion. Median NIHSS on admission was 9 (range 1-24) and it decreased to 4 (range 0-35) 24h after surgery, improving in 76.2% of patients. Patients with an ASPECTS of 6 (3 patients) showed an improvement of 66.7%, while it was of 81.8% in those starting with a score of 9 or 10 (11 patients). A mRS between 0 and 2 after 3months was achieved in 12 out of 21 patients. The average time elapsing between surgery and symptom onset was 410min (range 70-1070min). Fourteen patients treated within 8h from symptoms onset showed a clinical improvement of 85.7%, compared to a 57.1% for those which underwent later surgery. Four patients underwent thrombolytic therapy before CEA showing postoperative clinical improvement and no intracranial hemorrhage. Among the 14 patients who underwent CT perfusion, the median ischemic penumbra volume was 112 cc in those with clinical improvement (10 patients) and only 84 cc in those with worse clinical outcomes (4 patients). Emergency CEA in isolated eICA occlusion has proved to be a safe and effective treatment option in selected patients. CT perfusion, imaging the ischemic penumbra and quantifying the tissue suitable for reperfusion, offers a valid support in the diagnostic-therapeutic workup. Indeed, we can infer that the area of the ischemic penumbra is directly proportional to the margin of clinical improvement after revascularization, supposing that the appropriate intervention timing is respect.

Accuracy of Computed Tomography Angiography for Diagnosing Extracranial Mural Lesions in Patients with Acute Internal Carotid Artery Occlusion: Correlation with Digital Subtraction Angiography.

Extracranial carotid mural lesions (CML), caused by atherosclerosis or dissection, are frequently observed in acute internal carotid artery (ICA) occlusion, often requiring angioplasty or stenting. This study aimed to assess the diagnostic accuracy of computed tomography angiography (CTA) in differentiating extracranial CML from thromboembolic etiology in acute ICA occlusion in patients eligible for endovascular treatment. Two neuroradiologists retrospectively studied patients with apparent extracranial ICA occlusion on CTA. Patients were divided into two groups: thromboembolism and CML, based on findings from CTA and digital subtraction angiography (DSA). CTA sensitivity and specificity were calculated using DSA as the gold standard. Occlusive patterns and cervical segment widening were evaluated for atherosclerosis, dissection, and thromboembolism etiologies. CTA had a sensitivity of 84.91% (74.32-95.49%) and a specificity of 95.12% (87.31-100%) in detecting extracranial CML. Atherosclerosis was the most common cause, distinguishable with high accuracy using CTA (p < 0.001). No significant differences were found in occlusive patterns between dissection and thromboembolism (p = 0.568). Cervical segment widening was only observed in dissection cases due to mural hematoma. Conclusions: CTA accurately differentiates extracranial CML from thromboembolic etiology in acute ICA occlusion. The pattern of the occlusion and the artery widening help to establish the location and the etiology of the occlusion.

Automated measurement of carotid angle with use of CT images

Carotid stenosis is an important etiological factor in the forming of ischemic stroke. The weight of stroke which is formed as a result of extracranial internal carotid artery stenosis or occlusion differs according to the location, size of interaction, collateral supply, and the mechanisms those cause interact. Therefore, it is important to measure the narrowness of the carotid with the calculation of the bifurcation angle. In this study, CT cross-sectional image sequences are used. The images are unsupervised classified, and the carotid veins are identified with the boundaries and centers of the clusters. Then, the angles are calculated with three center points of the veins from successive images. The center point of the calculation is from the vein which has the maximum area difference between one of the successive images. The results are evaluated using 5 samples with visual interpretation regarding the position and the correctness of the three successive images which have maximum area jump.

Carotid artery stenting during endovascular thrombectomy for acute ischemic stroke with tandem occlusion: the Italian Registry of Endovascular Treatment in Acute Stroke.

The management of tandem extracranial internal carotid artery and intracranial large vessel occlusion during endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) has been under-investigated. We sought to investigate outcomes of AIS patients with tandem occlusion (TO) treated with carotid artery stenting (CAS) compared to those not treated with CAS (no-CAS) during EVT. We performed a cohort study using data from AIS patients enrolled in the Italian Registry of Endovascular Treatment in Acute Stroke. Outcomes were 3months' mortality, functional outcome, complete and successful recanalization, any intracranial hemorrhage, parenchymal hematoma and symptomatic intracerebral hemorrhage. Among 466 AIS patients with TO, CAS patients were 122 and no-CAS patients were 226 (118 excluded). After adjustment for unbalanced variables, CAS was associated with a lower rate of 3months' mortality (OR 0.407, 95% CI 0.171-0.969, p = 0.042). After adjustment for pre-defined variables, CAS was associated with a lower rate of 3months' mortality (aOR 0.430, 95% CI 0.187-0.989, p = 0.047) and a higher rate of complete recanalization (aOR 1.986, 95% CI 1.121-3.518, p = 0.019), successful recanalization (aOR 2.433, 95% CI 1.263-4.686, p = 0.008) and parenchymal hematoma (aOR 2.876, 95% CI 1.173-7.050, p = 0.021). CAS was associated with lower 3months mortality (OR 0.373, 95% CI 0.141-0.982, p = 0.046) and higher rates of successful recanalization (OR 2.082, 95% CI 1.099-3.942, p = 0.024) after adjustment for variables associated with 3months' mortality and successful recanalization, respectively. Among AIS patients with TO, CAS during EVT was associated with a higher rate of successful reperfusion and a lower rate of 3months' mortality.

Efficacy and safety of urgent carotid endarterectomy in patients with acute ischemic stroke.

Acute symptomatic occlusion of the internal carotid artery (ICA) is associated with unfavorable prognosis. However, no clear definition of its optimal treatment exists. The aim of this study was to evaluate the efficacy and risks of urgent carotid endarterectomy (CEA) in patients with ischemic stroke due to acute extracranial ICA occlusion. A retrospective analysis was performed of all consecutive patients undergoing urgent CEA for acute extracranial ICA occlusion during the period from July 2014 to June 2021. The primary outcome was functional independence at three months defined as modified Rankin Scale (mRS) score 2. Secondary outcomes included the severity of the neurological deficit at the time of discharge and its comparison with the preoperative condition as assessed using the National Institutes of Health Stroke Scale (NIHSS), the incidence of symptomatic intracerebral hemorrhage (ICH), and 30-day periprocedural mortality. During the study period, a total of 42 urgent CEAs were performed for acute extracranial ICA occlusions. The median preoperative NIHSS score was 7 (interquartile range [IQR] 5-13). The median time interval between the onset of symptoms and surgery was 290 minutes (IQR 235-340). Technical success rate of urgent CEA was 97.6% (41 patients). The median NIHSS at the time of hospital discharge was 2 (IQR 3-7; p.

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.

Passing Extracranial Artery Occlusion by Intermediate Catheter With Expanding Microballoon (PEACE): A Novel Endovascular Therapy in Acute Tandem Occlusion Stroke

Purpose: Endovascular treatment of atherosclerotic tandem occlusions in acute ischemic stroke (AIS) is a matter of debate. This article reports a single-center experience using an intermediate catheter with microballoon for treatment of tandem occlusions. Methods: A total of 151 AIS patients with large vessel occlusion received endovascular therapy and a consecutive series of patients (n = 26) who suffered from tandem cervical intracranial occlusions were treated using the Passing Extracranial Artery Occlusion by Intermediate Catheter with Expanding Microballoon (PEACE) technique. Intracranial recanalization was achieved by aspiration or stent retriever and then emergency stenting was performed for extracranial internal carotid artery (ICA) lesion. Demographic, clinical characteristics, procedural details of endovascular therapy, and prognosis outcome were assessed. The outcomes of tandem occlusion group were compared with isolated intracranial occlusion group (n = 122) and previous studies. Results: As compared to isolated intracranial occlusion groups, only a few patients suffered from atrial fibrillation (7.7% vs 38.5%, p<0.01) in tandem occlusions group. A larger proportion of patients (61.5% vs 29.5%) had tandem occlusions in which extracranial ICA occlusion was combined with intracranial terminus occlusion in ICA (p<0.01). 46.2% of tandem occlusions patients achieved intracranial recanalization by aspiration alone versus 15.6% in patients with isolated intracranial occlusion (p<0.01). In tandem occlusion patients treated with PEACE, 92.3% achieved successful reperfusion (thrombolysis in cerebral infarct [TICI] ≥2b). The median time from puncture to recanalization was 51 minutes (interquartile range [IQR], 41–66). 67.6% favorable functional prognosis (modified Rankin score [mRS], 0–2) was seen, with 11.5% mortality and 3.8% of symptomatic intracerebral hemorrhage (sICH) at 90 days. These outcomes are all consistent or better than previously reported studies performed for tandem occlusion. Conclusions: Endovascular therapy using the PEACE technique with intermediate catheter and lined expanding microballoon is safe, efficient, and fast in the treatment of atherosclerotic tandem occlusion patients.

Direct aspiration through a balloon guide catheter can augment vessel wall injury

AbstractWe report a 75‐year‐old woman with extracranial internal carotid artery occlusion treated with neurointervention. The patient presented with tandem lesions for which mechanical thrombectomy was performed. Retrieval of massive white clots and endothelial tissue by forceful manual aspiration via a balloon guiding catheter after angioplasty can be indicative of augmentation of vessel wall injury.

The perioperative complications and short-term death in endovascular treatment for acute stroke induced by extracranial carotid occlusion: a systematic review and a meta-analysis.

Endovascular treatment (EVT) has been demonstrated superior to pharmacological thrombolysis in acute ischemic stroke (AIS) induced by extracranial internal carotid artery occlusion. This paper aims to summarize clinical evidence about EVT and assess its efficacy and safety on acute extracranial carotid occlusion. We systematically reviewed all studies that reported endovascular therapy as carotid stenting, stent retriever, aspiration, and angioplasty for acute extracranial carotid occlusion. Literature retrieval was performed in PubMed, Embase, and Cochrane library, dated from January 1st, 2005 to December 31st, 2020. The primary endpoint was a favorable outcome rate. Major secondary endpoints were SICH incidence, 90-day mortality rate, and complications. Meta-analysis and subgroup analysis were conducted to identify predictors for prognosis. This systematic review has been registered in PROSPERO (CRD42020181154) on July 18, 2020. 10 studies with 620 patients were included in total. Endovascular approach presented a favorable outcome rate of 0.47 (0.37, 0.56), an acceptable 90-day mortality rate of 0.16 (0.13, 0.19), and a mild SICH rate of 0.07 (0.05, 0.10). Age and NIHSS at admission were negatively associated with favorable outcome, with odds ratio of 0.95 (0.92, 0.98) and 0.74 (0.62, 0.88) respectively. Lower age (p=0.049) and aspiration thrombectomy (p=0.041) predicted less SICH events. In subgroup in which time window > 6 hours, endovascular therapy presented similar encouraging results, with favorable outcome rate of 0.59 (0.51, 0.66), 90-day mortality rate of 0.11 (0.07, 0.17), and SICH rate of 0.04 (0.02, 0.09). EVT can effectively improve neurological function and reduce 90-day mortality for acute extracranial carotid occlusion patients without increasing the risk of symptomatic intracranial hemorrhage. Endovascular therapy is safe to perform from 6 to 24 hours after symptom onset.

Virgin Coconut Oil Attenuates Deficits in Rats Undergoing Transient Cerebral Ischemia

Background and Objectives. Neuroprotection agents may help improve the outcomes of large vessel ischemic stroke. This study aims to explore the role of Virgin Coconut Oil (VCO), with its well-documented anti-oxidant properties, in neuroprotection after transient occlusion of the extracranial internal carotid artery in a rat model of stroke.&#x0D; Methods. Twenty-three Sprague-Dawley rats were randomized into two groups: 1) control group (n=11) given distilled water, and 2) treatment group (n=12) given virgin coconut oil at 5.15 ml/kg body weight for seven days. Subsequently, the rats underwent transient right extracranial internal carotid artery occlusion (EICAO) for 5 minutes using non-traumatic aneurysm clips. At 4 and 24 hours after EICAO, the animals were examined for neurologic deficits by an observer blinded to treatment groups, then sacrificed. Eight brain specimens (4 from each group) were subjected to histopathologic examination (H &amp; E staining) while the rest of the specimens were processed using triphenyltetrazolium chloride (TTC) staining to determine infarct size and area of hemispheric edema.&#x0D; Results. VCO treatment significantly improved the severity of neurologic deficit (1.42 ± 2.31) compared to the control distilled water group (4.09 ± 2.59) 24 hours after EICAO. Whereas, infarct size and percent hemispheric edema did not significantly differ between the two groups.&#x0D; Conclusion. Prophylactic treatment of VCO is protective against EICAO-induced neurologic deficits in a rat model. VCO shows great potential as a neuroprotective agent for large vessel ischemic stroke. However, more studies are necessary to elucidate the neuroprotective mechanisms of VCO therapy in ischemic stroke.

Antiplatelet Therapy During Emergent Extracranial Internal Carotid Artery Stenting: Comparison of Three Intravenous Antiplatelet Perioperative Strategies

IntroductionGuidelines for antiplatelet therapy administration, during emergent stenting for extra-cranial internal carotid artery (EC-ICA) occlusion in the setting of acute ischemic stroke (AIS) are lacking. Different antiplatelet regimen are used in association to endovascular therapy (EVT) for the treatment of EC-ICA lesions. We aimed to compare the clinical and radiological effects of three intravenous antiplatelet agents used during emergent EC-ICA stenting. Material and MethodsClinical data were collected from January 2015 to December 2019 in a monocentric prospective registry of AIS patients treated by EVT. All patients who underwent emergent EC-ICA stenting were sorted regarding the intravenous antiplatelet agent used during the procedure. ResultsAmong 218 patients treated by EVT for an EC-ICA occlusion of the anterior circulation during the study period, 70 underwent an emergent stenting of the EC-ICA. 60 were included in the present study, 9 received intravenous (IV) Cangrelor, 8 IV abciximab and 43 Aspirin. The rate of favorable neurological outcome, defined as modified Rankin Scale (mRS) ≤ 2 at three months were better in the Cangrelor and Aspirin groups (66,7% and 58,1%, respectively) than in the Abciximab group (37,5%), as well as, the rate of any intracranial ICH (22,2% and 37,2% vs 62,5%). The rate of acute stent reocclusion was similar between groups. ConclusionWhen used as a rescue treatment during emergent stenting of EC-ICA, Cangrelor and Aspirin present a better safety profile than Abciximab, with less intracranial hemorrhages and a higher rate of good clinical outcome. Additional studies are needed to confirm these findings.

Median somatosensory evoked potential as a predictor of clinical outcome after urgent surgical extracranial internal carotid artery recanalization

ObjectiveChanges in the N20/P25 amplitude of somatosensory evoked potentials (SEP) of the median nerve have been found to correlate with those in cortical regional cerebral blood flow (rCBF). Our study presents the use of median nerve SEP amplitude in predicting the clinical outcome of urgent surgical internal carotid artery (ICA) recanalization. MethodsA total of 27 patients suffering an acute ischemic stroke (AIS) with extracranial ICA occlusion within 24 h were prospectively recruited. The primary preoperative endpoints included the SEP amplitude absolute value (SEP-amp) and the SEP amplitude side-to-side ratio (SEP-ratio).Clinical outcome at 3 months postoperatively was assessed using the modified Rankin scale (mRS-3M). ResultsThe positive predictive values (PPVs) for SEP-amp and SEP-ratio were 95.5% and 100%, respectively, with the negative predictive values (NPVs) being 60.0% and 100%, respectively. The SEP-ratio correlated fully with mRS-3M. ConclusionThe median SEP side-to-side N20/P25 amplitude ratio seems to be a very strong positive and negative predictor of the clinical outcome of urgent recanalization of an extracranial ICA occlusion. SignificanceThe results suggest that cortical evoked activity may help in selection patient for surgical recanalization and predict clinical recovery after an acute ischemic stroke.

Utility of Hounsfield unit in the diagnosis of tandem occlusion in acute ischemic stroke

BackgroundTandem occlusions can complicate medical and endovascular stroke treatment. To identify these occlusions, computed tomography angiography (CTA) represents the best imaging modality. However, CTA is still not initially performed in some patients not admitted directly to stroke centers. Early identification of an additional occlusion of the proximal extracranial internal carotid artery may improve the best suitable treatment strategy. The purpose of this study was to find a valuable threshold of thrombus attenuation in a non-contrast head CT (NCCT) scan to facilitate a safe diagnosis of tandem occlusions.Materials and methodsConsecutive patients with acute middle cerebral artery (MCA) occlusions who underwent endovascular treatment were identified from our registry of neuroendovascular interventions. Thrombus attenuations of the affected MCA and contralateral vessel were measured by NCCT. To compare individual baseline blood attenuations, the difference between the thrombus attenuation and the contralateral MCA attenuation (referred to as ΔTM) was calculated.ResultsThree hundred and twenty-five patients were included. There was a highly significant difference between mean thrombus attenuation with isolated MCA occlusion and additional extracranial internal carotid artery (ICA) occlusion (49.9 ± 8 vs. 56.2 ± 10 Hounsfield units (HU); P < 0.001). The area under the receiver operating characteristic curve of ΔTM was 0.72. The optimal threshold value was 13.5 HU, with a sensitivity of 67.5% and a specificity of 68.6%.ConclusionDespite a significant difference in thrombus attenuation in MCA occlusions with an additional extracranial ICA occlusion compared with isolated MCA occlusions, a relevant threshold of thrombus attenuation was not found.

Management and prognosis of acute extracranial internal carotid artery occlusion.

Acute occlusion of the internal carotid artery is the underlying etiology in 4 to 15% of all ischemic strokes. The clinical presentation varies considerably ranging from asymptomatic occlusion to severe ischemic strokes. Substantial differences in the acute management of acute symptomatic internal carotid artery occlusions (ICAO) exists between centers. Thusly, we comprised a narrative review of the natural course of acute ICAO and of available treatment options [i.v. thrombolysis, endovascular thrombectomy and stenting, bypass between the superficial temporal and the middle cerebral arteries (MCA) and carotid endarterectomy (CEA)]. We found that very few randomized treatment trials have been performed in patients acute symptomatic ICAO. Most evidence stems from case series and observational studies. Especially in older studies the intracranial vessel status has rarely been considered. After revision of these studies we concluded that the mainstay of the acute management of acute symptomatic ICAO is i.v. thrombolysis when applied within the label and in combination with mechanical thrombectomy in case of intracranial large vessel occlusion. In cases without intracranial large vessel occlusion mechanical thrombectomy of acute ICAO is associated with a risk of distal embolization. More research on prognostic parameters is needed to better characterize the risk of decompensation of collateral flow and to better define the time-window of intervention. When mechanical thrombectomy fails or is not available, surgical approaches are an alternative in selected patients.

Imaging Findings of Multiphase CT Angiography of Acute Internal Carotid Artery Occlusion Within 6-Hour Time-Window After Thrombectomy and Its Clinical Implication

Background: Intra-arterial thrombectomy (IAT) is one of the mainstream treatments for acute ischemic stroke. As relatively little evidence on extracranial internal carotid artery (ICA) occlusions exists in the literature, we share our experiences after using IAT for intracranial and extracranial ICA occlusions. We further clarify the imaging characteristics of multiphase computed tomography angiography (CTA) and share the experience of balloon angioplasty in acute ICA occlusion. Objectives: To investigate the imaging findings of multiphase CTA and the clinical conditions and outcomes of acute ICA occlusions at different segments after IAT. Patients and Methods: All participants receiving IAT for acute stroke with isolated ICA occlusions were included, obtained from three hospitals between June 2016 and November 2018. An imaging review for non-enhanced computed tomography (CT), multiphase CTA, and angiography was conducted. Epidemiological and clinical data were reviewed. Further comparisons were evaluated between the occlusion side from the C6 to C7 segments and C1 to C5 segments of the ICA. Results: The average age of the patients was 73.0 years, and the initial National Institutes of Health Stroke scale (NIHSS) score was 18.6. Nineteen percent of cases had good outcomes. Good reperfusion results were achieved in 50% of cases. Compared to the group with occlusion from C6-C7, the group with occlusion from C1-C5 had a relatively good Alberta Stroke Program Early CT score (ASPECTS) in the A1 phase of the multiphase CTA, and more patients had a good collateral. Three cases received a balloon angioplasty for a concurrent proximal cervical ICA tight stenosis, and all cases had good reperfusion results. Conclusion: Distal occlusion of the ICA demonstrates lower ASPECTS and a worse collateral on multiphase CTA. A multiphase CTA with an extended scan range in the A2 and A3 phases is able to exclude pseudo-occlusion of the ICA. Balloon angioplasty is helpful for concurrent proximal cervical ICA tight stenosis.

Outcome and effect of endovascular treatment in stroke associated with acute extracranial internal carotid artery occlusion: Single-center experience in Japan

BackgroundPositive data from several randomized controlled trials (RCTs) of endovascular treatment (EVT) for acute ischemic stroke (AIS) patients with anterior circulation large vessel occlusion (ACLVO) have emerged. However, little evidence exists on EVT for acute extracranial internal carotid artery (EC-ICA) occlusion. We therefore analysed the outcome and effect of EVT on AIS due to ACLVO caused by EC-ICA occlusion, including tandem occlusion compared with that caused by pure intracranial artery occlusion. MethodsA total of 135 consecutive AIS patients with ACLVO between July 2014 and December 2017 were identified. We retrospectively analysed the efficacy of EVT for ACLVO after introducing a stent retriever (SR). We classified ACLVO into the following categories: group A, intracranial artery occlusion without EC-ICA occlusion (pure intracranial artery occlusion), and group B, ipsilateral EC-ICA occlusion with/without intracranial artery occlusion. ResultsIn total, 65 patients were enrolled. Group A comprised 71% (46/65) of all cases. No difference was observed in terms of age, National Institute of Health Stroke Scale (NIHSS) score, Alberta Stroke Program Early Computed Tomography Score–Diffusion Weighted imaging (ASPECTS-DWI), several clinical time intervals, rate of successful revascularization (74% versus 84%), and rate of functional independence (42% versus 39%) between groups A and B. In all patients, an ASPECTS-DWI ≥6 and an onset-to-door time ≤6 h were associated with good outcome, whereas intracranial artery occlusion without EC-ICA occlusion (pure intracranial artery occlusion) was not. ConclusionsThe outcomes support the efficacy of EVT in stroke associated with acute EC-ICA occlusion. In the EVT of AIS due to ACLVO, there was no significant difference in the results between ipsilateral EC-ICA occlusion with/without intracranial artery occlusion and intracranial artery occlusion without EC-ICA occlusion (pure intracranial artery occlusion).

Abstract TP128: Determinants of Hemorrhagic Transformation After Emergent Extracranial Internal Carotid Artery Stenting for Tandem Occlusions

Background and Purpose: Extracranial internal carotid artery (ICA) lesion in the setting of tandem occlusions is a therapeutic challenge, and hemorrhagic transformation (HT) is one of the leading causes of poor clinical outcome. We aimed to determine determinants of HT for tandem occlusions undergoing emergent extracranial ICA stenting during endovascular treatment (EVT). Methods: We performed a prospective, observational cohort study of consecutive patients with non-cardioembolic ischemic stroke due to tandem occlusion who underwent EVT with extracranial ICA stent placement during the procedure from April 2013 to June 2019 in a single stroke center. We compared clinical (vascular risk factors, previous antiplatelet treatment, and IV rtPA), radiological (ASPECTS at admission and in-stent thrombosis at 24 hours) and serological (platelet count, fibrinogen, total cholesterol, HDL-cholesterol, and LDL-cholesterol) parameters according to the presence of HT in 24 hours CT-scan. Results: One-hundred and eight patients were included: 78.7% were men, mean age 68.5±14.3 years, median time from symptoms onset to treatment was 220 (150-337.5) minutes, median ASPECTS at admission was 9 (8-10). Eighty-six (79.6%) patients presented an extracranial ICA occlusion, and 22 (20.4%) a high-grade (&gt;50%) stenosis. In 88 (81.5%) patients the etiology of extracranial ICA lesion was ateroma, and in 20 (18.5%) was a dissection. Intravenous rtPA was administered in 47 (43.5%) patients. Successful recanalization (mTICI ≥2b) was achieved in 83 (76.9%) patients, and extracranial ICA recanalization in 108 (100%) patients. Type 2 diabetes (OR 1.5, 95% CI 1.1-3.5), higher fibrinogen levels (OR 4.6, 95% CI 1.6-12.9), and ASPECTS &lt;7 at admission (OR 2.1, 95% IC 1.1-5.1) were found as independent predictors of HT in multiple logistic regression analysis. Conclusions: Patients with a non-cardioembolic ischemic stroke due to tandem occlusion who present type 2 diabetes, higher fibrinogen levels, or ASPECTS &lt;7 at admission are at high risk of HT. In these particular cases, it might be useful to stent with a stent that does not need double antiplatelet treatment immediately after the procedure.