Distal Occlusion Research Articles

Neuroprotective Effects of Melittin Against Cerebral Ischemia and Inflammatory Injury via Upregulation of MCPIP1 to Suppress NF-κB Activation In Vivo and In Vitro

Melittin, a principal constituent of honeybee venom, exhibits diverse biological effects, encompassing anti-inflammatory capabilities and neuroprotective actions against an array of neurological diseases. In this study, we probed the prospective protective influence of melittin on cerebral ischemia, focusing on its anti-inflammatory activity. Mechanistically, we explored whether monocyte chemotactic protein-induced protein 1 (MCPIP1, also known as ZC3H12A), a recently identified zinc-finger protein, played a role in melittin-mediated anti-inflammation and neuroprotection. Male C57/BL6 mice were subjected to distal middle cerebral artery occlusion to create a focal cerebral cortical ischemia model, with melittin administered intraperitoneally. We evaluated motor functions, brain infarct volume, cerebral blood flow, and inflammatory marker levels within brain tissue, employing quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assays, and western blotting. In vitro, an immortalized BV-2 microglia culture was stimulated with lipopolysaccharide (LPS) to establish an inflammatory cell model. Post-melittin exposure, cell viability, and cytokine expression were examined. MCPIP1 was silenced using siRNA in LPS-induced BV-2 cells, with the ensuing nuclear translocation of nuclear factor-κB assessed through cellular immunofluorescence. In vivo, melittin enhanced motor functions, diminished infarction, fostered blood flow restoration in ischemic brain regions, and markedly inhibited the expression of inflammatory cytokines (interleukin-1β, interleukin-6, tumor necrosis factor-α, and nuclear factor-κB). In vitro, melittin augmented MCPIP1 expression in LPS-induced BV-2 cells and ameliorated inflammation-induced cell death. The neuroprotective effect conferred by melittin was attenuated upon MCPIP1 knockdown. Our findings establish that melittin-induced tolerance to ischemic injury is intrinsically linked with its anti-inflammatory capacity. Moreover, MCPIP1 is, at the very least, partially implicated in this process.

Mechanistic, participant, and movement-related factors that contribute to low-flow-mediated constriction.

Endothelial function is commonly determined via the ultrasound-based flow-mediated dilation (FMD) technique which assesses arterial dilation in response to a hyperemia response following distal cuff occlusion. However, the low-flow-mediated constriction (L-FMC) response during cuff-induced ischemia is often overlooked. L-FMC provides unique information regarding endothelial function, but vascular researchers may be unclear on what this metric adds. Therefore, the objective of this review was to examine the mechanistic determinants and participant-level factors of L-FMC. Existing mechanistic studies have demonstrated that vasoreactivity to low flow may be mediated via non-nitric oxide vasodilators (i.e., endothelial hyperpolarizing factors and/or prostaglandins), inflammatory markers, and enhancement of vasoconstriction via endothelin-1. In general, participant-level factors such as aging and presence of cardiovascular conditions generally are associated with attenuated L-FMC responses. However, the influence of sex on L-FMC is unclear with divergent results between L-FMC in upper versus lower limb vessels. The ability of aerobic exercise to augment L-FMC (i.e., make more negative) is well supported, but there is a major gap in the literature concerning the mechanistic underpinnings of this observation. This review summarizes that while larger L-FMC responses are generally healthy, the impact of interventions to augment/attenuate L-FMC has not included mechanistic measures that would provide insight into non-nitric oxide-based endothelial function. Clarifications to terminology and areas of further inquiry as it relates to the specific pharmacological, individual-level factors, and lifestyle behaviors that impact L-FMC are highlighted. A greater integration of mechanistic work alongside applied lifestyle interventions is required to better understand endothelial cell function to reductions in local blood flow.

The CineECG in ischemia localization in ST-elevation (equivalent) acute coronary syndromes

Aim of the studyIn this proof of concept study we aimed to visualize and quantify the injury vectors using the CineECG in representative examples of ST elevation acute myocardial infarction (STEMI) and STEMI-equivalent electrocardiograms (ECG's). For this purpose ECG's were selected with different ST deviation patterns in acute anterior wall, inferior or posterolateral wall infarctions. MethodsThe ST-amplitudes of the individual leads were measured between J-point and 60 ms after the J-point. These data were used to compute the direction and size (i.e. ST-amplitudes) of the injury vectors of the respective STEMI (equivalent)’s and displayed in the frontal, transverse and sagittal view. The relative contribution of the ST vector was computed for each axis (X,Y,Z) and per view using the length of the projected ST vector on the respective plane. ResultsThe injury vectors accurately pointed to the area at risk in either proximal, mid or distal occlusions of the respective coronary arteries. Moreover in LCX occlusions, where no or small ST abnormalities in the standard ECG were present, the CineECG was found to be capable in pointing towards the ischemic area. Especially the visualization of the ST-vector in the sagittal plane was found to be contributing. ConclusionsThese findings suggest that the CineECG could become a useful additional tool to support the clinician. Moreover our preliminary findings suggest that CineECG may be more capable in detecting ischemic changes in situations where the ECG is not supportive, such as in LCX occlusions. Further studies in patient cohorts are needed to confirm these observations.

PREVALENCE OF DENTAL ANOMALIES OF CLASS II, SUBCLASS 2 IN CHILDREN DURING THE PERIOD OF MIXED DENTITION

Distal malocclusion is the only type of malocclusion that requires urgent treatment as soon as possible before maxillary discrepancy occurs. The incidence in the population varies around 45%, depending on age, racial group and types of distal malocclusion studied. We studied the frequency of occurrence of distal occlusion and its varieties among 20 children and adolescents with dental anomalies aged 6-13 years. Determining the types of such a complex anomaly as distal occlusion allows for more thorough treatment planning and positive, lasting results.

TCT-365 Comparison of Distal Filter Protection Versus Proximal Balloon Occlusion for Carotid Artery Stenting: Results From a Registry of 2,180 Patients

TCT-365 Comparison of Distal Filter Protection Versus Proximal Balloon Occlusion for Carotid Artery Stenting: Results From a Registry of 2,180 Patients

Hydrogen‑rich saline promotes neuronal recovery in mice with cerebral ischemia through the AMPK/mTOR signal‑mediated autophagy pathway.

This study explored the protective effect and mechanism of hydrogen‑rich saline (HRS) on the neurological function of mice with cerebral ischemia. Effects of HRS on neurological function in mice with cerebral ischemia were evaluated by neurological function scores. Infarct volume and histological damage were evaluated by 2,3,5‑triphenyl tetrazolium chloride staining (TTC staining). Golgi‑Cox staining was conducted to measure the morphological changes of neuronal dendrites and dendritic spines. The expression of neuronal markers was detected by immunofluorescence. Western blot was used to detect protein expression. The infarct volume of mice in the HRS‑H group decreased significantly compared to that of the distal middle cerebral artery occlusion (dMCAO) group. Mice in the HRS‑H group had a lower neurological deficit score than that in the dMCAO group. Compared to the dMCAO group, the activity of superoxide dismutase (SOD) and the level of glutathione (GSH) significantly increased in the HRS‑H group. Compared with the dMCAO group, the number of apoptotic cells in the HRS‑H group decreased. Administration of HRS was shown to be able to decrease cavitation of the brain cortex after ischemia. The spine density in the HRS‑H group increased compared to that of the dMCAO group. In the in vitro experiment, compared with the oxygen‑glucose deprivation (OGD) group, the active oxygen content in the 75% HRM group decreased, and the mitochondrial membrane potential and adenosine triphosphate (ATP) content increased. Compared with the OGD group, the ratio of P‑AMPK and the levels of LC3II/LC3I in the hydrogen‑rich medium (HRM) group was upregulated, and P‑mTOR levels and P62 levels in the HRM group were down‑regulated. HRS can enhance neuroplasticity after ischemia and promote neurological recovery in mice with cerebral ischemia, which may involve the autophagy pathway mediated by the AMPK/mTOR signaling pathway.

Protective effects of low-intensity pulsed ultrasound (LIPUS) against cerebral ischemic stroke in mice by promoting brain vascular remodeling via the inhibition of ROCK1/p-MLC2 signaling pathway.

Vascular remodeling is essential for patients with cerebral ischemic stroke (CIS). Our previous study proved that low-intensity pulsed ultrasound (LIPUS) could increase cortical hemodynamics. However, the effects and mechanisms of LIPUS on cerebral vascular remodeling after CIS are still unknown. In this study, we applied LIPUS to the mouse brain at 0.5h after distal middle cerebral artery occlusion (dMCAO) and subsequently daily for a stimulation time of 30min. Results showed that compared with the dMCAO group, LIPUS markedly increased cerebral blood flow (CBF), reduced brain swelling, and improved functional recovery at day 3 after CIS. LIPUS promoted leptomeningeal vasculature remodeling, enlarged vascular diameter, and increased the average vessel length and density at day 3 after CIS. Proteomic analysis highlighted that LIPUS mainly participated in the regulation of actin cytoskeleton pathway. Rho kinase 1 (ROCK1) was downregulated by LIPUS and participated in regulation of actin cytoskeleton. Subsequently, we verified that ROCK1 was mainly expressed in pericytes. Furthermore, we demonstrated that LIPUS inhibited ROCK1/p-MLC2 signaling pathway after CIS, which had positive effects on vascular remodeling and cerebral blood circulation. In conclusion, our preliminary study revealed the vascular remodeling effects and mechanism of LIPUS in CIS, provided evidence for potential clinical application of LIPUS.

Evaluation of total occlusal contact area in children with physiologic and distal occlusion

Relevance. Total occlusal contact area assessment is an important tool for malocclusion diagnosing and treatment planning in children.Purpose. The study aimed to evaluate (during six months) the effect of orthodontic treatment with plates and trainers on the change in the total occlusal contact area in children with distal occlusion compared to children with physiologic occlusion.Material and methods. The study groups included 145 children with distal occlusion: Group I (82 patients) was treated with a plate modified by AM Schwartz, and Group II (63 patients) had silicone trainers. The control group consisted of 42 children with physiologic occlusion who had not previously had orthodontic treatment. The T-Scan III assessed the total occlusal contact area before and during six months of treatment.Results. The analysis of total occlusal contact area changes in children with physiologic and distal occlusion revealed a statistically significant (p < 0,05) increase in the orthodontic treatment groups (plates and silicone trainers) in 3 and 6 months. Comparative analysis showed a smaller total occlusal contact area in children with distal occlusion before the treatment.Conclusion. Patients with distal occlusion demonstrated a smaller total occlusal contact area before the treatment compared to patients with physiologic occlusion. The children with distal occlusion showed a total occlusal contact area increase during 6-month orthodontic treatment.

Contemporary Methods for Detection and Intervention of Distal Medium and Small Vessel Occlusions.

The efficacy of using mechanical thrombectomy for proximal large vessel occlusions has been demonstrated in multiple large-scale trials and has further raised the question of its potential utility for distal medium and small vessel occlusions (DMSVOs). Their longer, more tortuous course and smaller corresponding vascular territories render a significant challenge for detection and intervention. The aim of this study is to provide a comprehensive overview of the current imaging and endovascular intervention options for DMSVOs and review the current works in the literature. Compared with traditional computed tomography angiography (CTA) and CT perfusion, recent advances such as multiphase CTA and maps derived from the time-to-maximum parameter coupled with artificial intelligence have demonstrated increased sensitivity for the detection of DMSVOs. Furthermore, newer generations of mini stent retrievers and thromboaspiration devices have allowed for the access and navigation of smaller and more fragile distal arteries. Preliminary studies have suggested that mechanical thrombectomy using this newer generation of devices is both safe and feasible in distal medium-sized vessels, such as M2. However, endovascular intervention utilizing such contemporary methods and devices must be balanced at the discretion of operator experience and favorable vascular anatomy. Further large-scale multicenter clinical trials are warranted to elucidate the indications for as well as to strengthen the safety and efficacy of this approach.

Thrombectomy for proximal intracranial occlusion beyond 24 hours after time last seen normal: A narrative review

Endovascular thrombectomy (EVT) revolutionized the treatment for acute ischemic stroke due to large vessel occlusion (LVO). Current guidelines published by multiple academic societies recommend EVT for eligible patients who present within 24 hours of the time last seen well. However, more recent data suggests that extending this window past 24 hours produces more favorable outcomes in specific patients presenting with anterior circulation LVO. More specifically, recent observational data indicates a higher probability of functional independence, functional improvement, and long-term survival with EVT when compared to best medical management. Based on the available data, there is unclear equipoise in randomizing all patients with acute ischemic stroke due to LVO to EVT or medical management. However, for those patients with large established infarction, distal occlusions, or well beyond the 24-hour window, randomized clinical trials are called upon to determine whether there is benefit of EVT in these patient groups. In this narrative review, we will summarize the most recent data on EVT in the ultra extended window (>24 hours after time last seen normal) and discuss further considerations of this treatment.

Outcomes of a Modified Technique for Deflation of Distal Radial Artery Occlusion Device on Radial Artery Patency After Percutaneous Coronary Intervention.

This study aimed to compare two protocols of deflation with increased intervals versus late deflation with smaller intervals for distal radial artery occlusion device (DROAD) removal to assess for radial artery occlusion (RAO). All patients who underwent PCI with distal radial access were enrolled in the study. The DROAD was applied using an occlusive hemostasis method. Patients were assigned to either protocol 1 or protocol 2 at the primary physician's discretion. Protocol 1 involved the removal of 2 ml of air starting 1 h after the sheath removal and then the removal of 2 ml every 30 min until the band came off. Protocol 2 involved the removal of 4 ml of air 2 h after the sheath removal and then a further 4 ml of air every 15 min until the band came off. A total of 446 patients were enrolled in this study (mean age; 61 ± 6 (Group 1) and 60 ± 5 (Group 2); females 45.83% (Group 1) and 46.34% (Group 2)). The baseline characteristics were the same, including mean hemostasis time (256 ± 25 min (Group 1) and 254 ± 28 min (Group 2), P-value = 0.611). Primary and secondary endpoints did not reach significance in either group (RAO; 21 (8.71) Group 1 and 18 (8.78) Group 2 (P-value = 0.932)). Age (OR (95%CI): 1.07 (0.57-1.45); P-value = 0.031), female gender (OR (95%CI): 1.42 (0.93-1.74); P-value = 0.012), distal artery diameter (OR (95%CI): 0.57 (0.21-0.93); P-value = 0.005), procedure time (OR (95%CI): 2.64 (0.95-4.32); P-value = 0.001), and sheath size (OR (95%CI): 2.47 (1.43-3.76); P-value = 0.044) were predictors of RAO in our cohort. This investigation shows no difference in the incidence of RAO with the standard versus accelerated deflation protocol after PCI. However, local vascular complications, including hematoma were increased with the accelerated protocol.

Development of machine learning models for predicting outcome in patients with distal medium vessel occlusions: a retrospective study.

While numerous prognostic factors have been reported for large vessel occlusion (LVO)-acute ischemic stroke (AIS) patients, the same cannot be said for distal medium vessel occlusions (DMVOs). We used machine learning (ML) algorithms to develop a model predicting the short-term outcome of AIS patients with DMVOs using demographic, clinical, and laboratory variables and baseline computed tomography (CT) perfusion (CTP) postprocessing quantitative parameters. In this retrospective cohort study, consecutive patients with AIS admitted to two comprehensive stroke centers between January 1, 2017, and September 1, 2022, were screened. Demographic, clinical, and radiological data were extracted from electronic medical records. The clinical outcome was divided into two categories, with a cut-off defined by the median National Institutes of Health Stroke Scale (NIHSS) shift score. Data preprocessing involved addressing missing values through imputation, scaling with a robust scaler, normalization using min-max normalization, and encoding of categorical variables. The data were split into training and test sets (70:30), and recursive feature elimination (RFE) was employed for feature selection. For ML analyses, XGBoost, LightGBM, CatBoost, multi-layer perceptron, random forest, and logistic regression algorithms were utilized. Performance evaluation involved the receiver operating characteristic (ROC) curve, precision-recall curve (PRC), the area under these curves, accuracy, precision, recall, and Matthews correlation coefficient (MCC). The relative weights of predictor variables were examined using Shapley additive explanations (SHAP). Sixty-nine patients were included and divided into two groups: 35 patients with favorable outcomes and 34 patients with unfavorable outcomes. Utilizing ten selected features, the XGBoost algorithm achieved the best performance in predicting unfavorable outcomes, with an area under the ROC curve (AUROC) of 0.894 and an area under the PRC curve (AUPRC) of 0.756. The SHAP analysis ranked the following features in order of importance for the XGBoost model: mismatch volume, time-to-maximum of the tissue residue function (Tmax) >6 s, diffusion-weighted imaging (DWI) volume, neutrophil-to-platelet ratio (NPR), mean corpuscular volume (MCV), Tmax >10 s, hemoglobin, potassium, hypoperfusion index (HI), and Tmax >8 s. Our ML models, trained on baseline quantitative laboratory and CT parameters, accurately predicted the short-term outcome in patients with DMVOs. These findings may aid clinicians in predicting prognosis and may be helpful for future research.

Basilar artery occlusion location and clinical outcome: data from the ATTENTION multicenter registry

BackgroundAcute basilar artery occlusion is a disabling and life-threatening condition. The purpose of this study was to evaluate the impact of occluded vessel location on the prognostic outcomes of patients...

Coronary Embolism After Transcatheter Aortic Valve Replacement—Case Series and Review of Literature

Periprocedural systemic embolism is a well-documented complication of transcatheter aortic valve replacement (TAVR). Although the most focus was given to cerebral embolism (which remains unpredictable, difficult to prevent, and a source of increased morbidity and mortality after TAVR), coronary embolism remains less investigated and potentially overlooked. This study provides a case series of 3 patients diagnosed with coronary embolism after TAVR in our institution over a 2-year period (3 of 297 cases, 1%) and a systematic literature review (4 studies; 19 case reports). Overall, coronary embolism associated with TAVR is frequently characterized by proximal vessel occlusion causing ST-elevation myocardial infarction and hemodynamic instability with lower mortality in the acute phase as compared with late coronary embolism. However, it often presents with distal vessel occlusion and minor symptoms that may be overlooked in the periprocedural period. In conclusion, we suggest that TAVR-associated coronary embolism has a much higher prevalence than previously documented. Further studies are warranted to properly assess the prevalence and impact of this phenomenon.

ОЦЕНКА ВЕРХНИХ ДЫХАТЕЛЬНЫХ ПУТЕЙ И ОКРУЖАЮЩИХ МЯГКИХ ТКАНЕЙ У ПАЦИЕНТОВ С АНОМАЛИЯМИ ОККЛЮЗИИ В САГИТТАЛЬНОЙ ПЛОСКОСТИ ПО ДАННЫМ КОНУСНО-ЛУЧЕВОЙ КОМПЬЮТЕРНОЙ ТОМОГРАФИИ

The relationship between facial morphology and upper airway (UA) dimensions is well established in scientific literature. Due to that, upper airway assessment is an important step of orthodontic treatment planning and diagnosis. Three-dimensional cone-beam computer tomography analysis (CBCT) of upper airway is simple and readily available method of measuring linear and angular parameters, cross-sectional area, and volume of the UA. 
 The aim of the study is to measure the UA and surrounding tissue dimensions in patients with different types of sagittal malocclusion. 63 CBCT scans of adult patients without history of trauma, orthodontic treatment and congenital syndromes, diagnosed with distal, mesial, and normal occlusion have been studied using Materialise Mimics 21.0. Three-dimensional models of UA were created, and measurements of volume and cross-sectional area were taken using centerline and conventional cephalometric analysis. Non-parametric statistical correlational analysis was conducted.
 There were statistically significant differences between patients with mesial and distal occlusion. Moderate statistically significant correlations between facial morphology and UA dimensions have been found. In patients with distal occlusion, extended head position, posterior position of the hyoid bone, transverse maxillary and mandibular deficiency UA tend to have smaller size. The most predictive factor for minimal cross-sectional area of UA is the craniocervical angle and the distance between mandibular condyles.

The effect of occlusion location and technique in mechanical thrombectomy for minor stroke.

Endovascular mechanical thrombectomy (MT) is an established treatment for large vessel occlusion strokes with a National Institutes of Health Stroke Scale (NIHSS) score of 6 or higher. Data pertaining to minor strokes, medium, or distal vessel occlusions, and most effective MT technique is limited and controversial. A multicenter retrospective study of all patients treated with MT presenting with NIHSS score of 5 or less at 29 comprehensive stroke centers. The cohort was dichotomized based on location of occlusion (proximal vs. distal) and divided based on MT technique (direct aspiration first-pass technique [ADAPT], stent retriever [SR], and primary combined [PC]). Outcomes at discharge and 90 days were compared between proximal and distal occlusion groups, and across MT techniques. The cohort included 759 patients, 34% presented with distal occlusion. Distal occlusions were more likely to present with atrial fibrillation (p = 0.008) and receive IV tPA (p = 0.001). Clinical outcomes at discharge and 90 days were comparable between proximal and distal groups. Compared to SR, patients managed with ADAPT were more likely to have a modified Rankin Scale of 0-2 at discharge and at 90 days (p = 0.024 and p = 0.013). Primary combined compared to ADAPT, prior stroke, multiple passes, older age, and longer procedure time were independently associated with worse clinical outcome, while successful recanalization was positively associated with good clinical outcomes. Proximal and distal occlusions with low NIHSS have comparable outcomes and safety profiles. While all MT techniques have a similar safety profile, ADAPT was associated with better clinical outcomes at discharge and 90 days.

Ketamine improves neuronal recovery following spreading depolarization in peri-infarct tissues.

Spreading depolarization (SD) has emerged as an important contributor to the enlargement of acute brain injuries. We previously showed that the N-methyl-D-aspartate receptor antagonist ketamine was able to prevent deleterious consequences of SD in brain slices, under conditions of metabolic compromise. The current study aimed to extend these observations into an in vivo stroke model, to test whether gradients of metabolic capacity lead to differential accumulation of calcium (Ca2+) following SD. In addition, we tested whether ketamine protects vulnerable tissuewhile allowing SD to propagate through surrounding undamaged tissue. Focal lesions were generated using a distal middle cerebral artery occlusion in mice, and clusters of SD were generated at 20 min intervals with remote microinjection of potassium chloride. SDs invading peri-infarct regions had significantly different consequences, depending on the distance from the infarct core. Proximal to the lesion, Ca2+ transients were extended, as compared with responses in better-perfused tissue more remote from the lesion. Extracellular potential shifts were also longer and hyperemia responses were reduced in proximal regions following SDs. Consistent with in vitro studies, ketamine, at concentrations that did not abolish the propagation of SD, reduced the accumulation of intracellular Ca2+ in proximal regions following an SD wave. These findings suggest that deleterious consequences of SD can be targeted in vivo, without requiring outright block of SD initiation and propagation.

Distal Endovascular Occlusion for Incomplete Occlusion of Cavernous Carotid Aneurysms after High-flow Bypass and Cervical Internal Carotid Artery Ligation.

Internal carotid artery (ICA) ligation for placing a high-flow extracranial-intracranial (EC-IC) bypass is used in patients with aneurysms on the cavernous portion of the ICA. Recanalization and rupture after proximal ICA ligation can occur. We present four patients who underwent endovascular distal ICA occlusion and report our surgical technique and treatment results. We ligated the ICA to place an EC-IC bypass using a radial artery (RA) graft. Failure to obtain spontaneous occlusion in the distal region required endovascular treatment an average of 219 days later. A guide catheter was placed in the common carotid artery, a guide or distal access catheter was introduced in the RA graft from the external carotid artery, and a microcatheter was navigated into the cavernous aneurysm through the RA graft. Using detachable coils, endovascular ICA occlusion was from just distal to the aneurysmal neck to a site proximal to the origin of the ophthalmic artery. Aneurysmal occlusion was completed by endovascular occlusion of the distal ICA. Complications were RA graft stenosis and transient consciousness disturbance due to local subarachnoid hemorrhage. Outpatient follow-up for a mean of 109.5 months revealed no recurrences. Distal occlusion of the ICA through the implanted RA graft is simple and presents a low risk for cerebral infarction due to thrombus formation during the procedure. To treat cavernous carotid aneurysms that do not disappear after placing the EC-IC bypass after ICA ligation at the aneurysmal neck, we offer our procedure as a treatment option.

Hemodynamic Characteristics of Intracranial Atherosclerotic Stenosis: A Pilot Study of Contrast Enhancement Time-Density Curves Based on Regions of Interest.

The present study aimed to analyze the hemodynamic characteristics of occluded vessels responsible for acute ischemic stroke and to diagnose the occlusion types. Multimodal computed tomography (CT) was used to accurately identify the range of occlusion of large intracranial vessels. Regions of interest (ROI 1-3 ) were manually delineated at sites 2 mm away from the proximal, middle, and distal portions of each occlusion, generating 3 contrast enhancement time-density curves. The peak CT attenuation values, or Hounsfield units (H 1-3 ), and time-to-peak values (T 1-3 ) were extracted from each curve. H 0 and T 0 of the time-density curve, based on ROI 0 of the automatically recognized input artery, were used as the baseline values with which the odds ratios of each parameter, H 1-3/0 and T 1-3/0 , were obtained. The present study aimed to establish prediction models for intracranial atherosclerotic stenosis (ICAS) based on each ROI's time-density curve. Among the 33 acutely occluded intracranial vessels, 10 were found to have ICAS, whereas 23 did not, based on the diagnostic criteria. Significant differences were observed in patient sex, neutrophil-to-lymphocyte ratio upon admission, Alberta Stroke Program Early CT Score 24-48 hours after reperfusion therapy, and H 1/0 , H 3/0 , and T 3/0 between the ICAS and non-ICAS groups ( P < 0.05). The prediction model (model 3) based on the ROI 3 time-density curve showed the best performance for the diagnosis of ICAS (area under the curve, 0.944; 95% confidence interval, 0.854-1.000). The prediction models based on ROI 1 (model 1) and ROI 2 (model 2) showed moderate diagnostic performance (area under the curve, 0.817 vs 0.822, respectively). The best visualization for proximal occlusions was in the first phase (arterial phase) of multiphase CT angiography, and in the second phase (early venous phase) for distal occlusions. The contrast enhancement time-density curves of the ROIs at all evaluated portions of the acute ischemic stroke occlusions provided a visual display of the blood flow characteristics of the responsible vessels. The time-density curve of the ROI placed 2 mm from the distal occlusion was a combined effect of residual blood flow and collateral establishment, thus providing good performance for the diagnosis of ICAS.

Update on Neurointerventional Therapy for the Treatment of Acute Cerebral Ischemia.

Mechanical thrombectomy (MT) is a minimally invasive, fluoroscopically guided procedure to remove clots from the arteries in the head and neck. The procedure can be performed very quickly and effectively, with low complication rates, as techniques and technology have advanced in recent years. MT is among the most efficacious procedures performed today, with a very low number needed to treat (NNT) to impact outcomes. Expanded indications for MT include patients with large core infarcts, extended time windows from stroke onset, more distal occlusions, and milder symptoms. Trials have shown a significant benefit of MT in terms of reduced disability in nearly every patient population studied.