Site Of Occlusion Research Articles

Abstract WP2: Natural History of Large Vessel Occlusion Patients Presenting With Minor Stroke Symptoms

Background: Acute ischemic stroke is a leading cause of mortality and disability in the US, with 50% of patients with minor stroke symptoms (MSS). Large vessel occlusion (LVO) is found in 10% of MSS cases and predicts poor neurological outcomes. However, treatment strategies for MSS-LVO lack consensus, and a deeper understanding of the natural history of MSS-LVO is needed. Methods: We screened all patients presenting to a large stroke network, from May 2017 to August 2023, for intracranial anterior circulation LVO and MSS (NIHSS %lt 6). Descriptive statistics were applied to demographic, clinical, radiographic, and neurological outcomes data, including early neurological deterioration (END) (NIHSS gain 3+). Results: Ninety patients participated in the study, averaging 64.5 years old, with 58.8% male, 48.8% white, 22.2% black, and 16.2% Hispanic. Comorbidities included diabetes (23%), hypertension (67.7%), atrial fibrillation (22%), hyperlipidemia (53%), and smoking (40%). Patients arrived with mean 7 hours (SE 1.6) from LKW, and a mean NIHSS 3.95 (SE 0.40). The majority of patients had baseline mRS of 0-2 (92.6%). Occlusion sites included M1 (38.9%), M2 (40%), and ICA terminus (2.2%). The mean ASPECTS score was 9.4 (SE 0.13). Immediate thrombolytic treatment was delivered to 34% of patients. Out of 90 patients, 31 (34%) suffered END, with mean NIHSS at END of 9.17 (SE 0.85), necessitating rescue endovascular thrombectomy (EVT). Collateral vessel failure caused 87.1% of END cases, clot migration 9.7%, and additional strokes 3.2%. Of the 31 EVT cases, 29 (93%) achieved TICI 2b-3, averaging 3.1 (SE 0.35) passes. ICH occurred in 5 patients; 2 had undergone EVT, although none were symptomatic. At 24 hours and 5 days from presentation, the mean NIHSS were 3.15 and 2.86 respectively, worse in END patients (6.16 vs 1.55, p=0.00, and 6.28 vs 1.14, p=0.00). After 30 days, only 66% of END patients had mRS of 0-2 compared to 84% of non-END patients (p=0.02). Similarly, at 90 days, only 65% of END patients, versus 86% of non-END patients, had mRS of 0-2 (p=0.02). Conclusion: The study details the natural history of MSS-LVO, showing a prominent incidence of EVT-requiring END due to collateral failure. Future research should identify high-risk END patients for tailored treatment.

Impact of stalling events on microcirculatory hemodynamics in the aged brain.

The role of cerebral microvasculature in cognitive dysfunction can be investigated by identifying the impact of blood flow on cortical tissue oxygenation. In this paper, the impact of capillary stalls on microcirculatory characteristics such as flow and hematocrit (Ht) in the cortical angioarchitecture is studied. Using a deterministic mathematical model to simulate blood flow in a realistic mouse cortex, hemodynamics parameters, including pressure, flow, vessel diameter-adjustable hematocrit, and transit time are calculated as a function of stalling events. Using a non-linear plasma skimming model, it is observed that Ht increases in the penetrating arteries from the pial vessels as a function of cortical depth. The incidence of stalling on Ht distribution along the blood network vessels shows reduction of RBCs around the tissue near occlusion sites and decreased Ht concentration downstream from the blockage points. Moreover, upstream of the occlusion, there is a noticeable increase of the Ht, leading to larger flow resistance due to higher blood viscosity. We predicted marked changes in transit time behavior due to stalls which match trends observed in mice invivo. These changes to blood cell quantity and quality may be implicated in the development of Alzheimer's disease and contribute to the course of the illness.

A "Radial Ready" Tricoaxial Setup for Anterior Circulation Mechanical Thrombectomy: Technical Aspects and Preliminary Results.

Mechanical thrombectomy (MT) is the standard of care for acute ischemic stroke (AIS) due to large vessel occlusion (LVO). The choice of a transradial approach (TRA) for anterior circulation LVOs is still debatable; the use of a specific tricoaxial system could help mitigate numerous issues related to transradial MT. From November 2022 to November 2023, 22 patients underwent TRA-MT for anterior circulation LVOs, both as first-line and rescue from transfemoral approach (TFA) failure, with the same triaxial setup consisting of a 7F introducer sheath, 7F guide catheter, and aspiration catheters ranging from 5.5F to 5F in relation to the occlusion site. Choice of thrombectomy technique was at operator discretion. Patients' demographic data, clinical presentation, treatment details, complications, rate of crossover to TFA, successful revascularization (modified thrombolysis in cerebral infarction [mTICI] score ≥2b), and good clinical outcome at 3 months (modified Rankin scale [mRS] 0-2) were reported. Of 20 patients selected, 10 (50%) had occlusion of M1 segment of middle cerebral artery (MCA), 6 (30%) of internal carotid artery (ICA) terminus, and 4 (20%) with M2 MCA occlusions; 12/20 (60%) were right-sided occlusions and 8/20 (40%) were left-sided. The mean National Institutes of Health Stroke Scale score was 9.25 at admission. Successful revascularization to mTICI 2b-3 was achieved in 18/20 patients (90%). Intracranial complications were reported in 2 (10%) patients. Rate of radial artery occlusion at 24 hours was 10,6%; no access-site haemorrhagic complications were reported. Symptomatic intracranial hemorrhage occurred in 2 (10%) patients. mRS score 0-2 at 3 months was 50%. The high technical effectiveness and good safety profile of this specific tricoaxial setup for TRA-MT in AIS, even for large proximal LVOs, could constitute a viable alternative to TFA-MT in selected cases.

A 4-year tunneled hemodialysis catheter malpositioned into the azygos vein and how to remedy the hemodialysis circuit.

Mispositioning in the azygos vein is a rare but hazardous complication of central venous catheterization. A patient was admitted for a dysfunctional hemodialysis tunneled cuffed catheter (TCC) placed in the azygos vein for 4 years. Computed tomography angiography revealed multiple sites of occlusion, including the superior vena cava (SVC), right and left innominate veins (IVs), and right femoral vein. Percutaneous transluminal angioplasty and a TCC replacement based on a segment-by-segment recanalizing strategy were performed. First, an 8-Fr sheath was inserted through the left femoral vein approach to retrogradely traverse the occlusive SVC followed by a guidewire extending to the occlusive left IV. A left transjugular 15-cm snare was inserted to capture the transfemoral guidewire and achieve recanalization from the left IV to the SVC. Second, a transjugular guidewire was advanced through the dysfunctional TCC yet shunted into the left IV due to the inability to cross the SVC. A left transfemoral 15-cm snare was inserted to capture the guidewire and achieve complete recanalization from the right internal jugular vein to the SVC. Balloons were passed over the guidewires to dilate the obstructive lesions sequentially, and a new TCC was inserted successfully with the tip positioned in the right atrium.

Sex-Based Analysis of Workflow and Outcomes in Acute Ischemic Stroke Patients Treated With Alteplase Versus Tenecteplase.

Understanding sex differences in stroke care is important in reducing potential disparities. Our objective was to explore sex differences in workflow efficiency, treatment efficacy, and safety in the AcT trial (Alteplase Compared to Tenecteplase). AcT was a multicenter, registry-linked randomized noninferiority trial comparing tenecteplase (0.25 mg/kg) with alteplase (0.9 mg/kg) in acute ischemic stroke within 4.5 hours of onset. In this post hoc analysis, baseline characteristics, workflow times, successful reperfusion (extended Thrombolysis in Cerebral Infarction score ≥2b), symptomatic intracerebral hemorrhage, 90-day functional independence (modified Rankin Scale score, 0-1), and 90-day mortality were compared by sex. Mixed-effects regression analysis was used adjusting for age, stroke severity, and occlusion site for outcomes. Of 1577 patients treated with intravenous thrombolysis (2019-2022), 755 (47.9%) were women. Women were older (median, 77 [68-86] years in women versus 70 [59-79] years in men) and had a higher proportion of severe strokes (National Institutes of Health Stroke Scale score >15; 32.4% versus 24.9%) and large vessel occlusions (28.7% versus 21.5%) compared with men. All workflow times were comparable between sexes. Women were less likely to achieve functional independence (31.7% versus 39.8%; unadjusted relative risk, 0.80 [95% CI, 0.70-0.91]) and had higher mortality (17.7% versus 13.3%; unadjusted relative risk, 1.33 [95% CI, 1.06-1.69]). Adjusted analysis showed no difference in outcomes between sexes. Differences in prognostic factors of age, stroke severity, and occlusion site largely accounted for higher functional dependence and mortality in women. No sex disparities were apparent in workflow quality indicators. Given the integration of the AcT trial into clinical practice, these results provide reassurance that no major sex biases are apparent in acute stroke management throughout participating Canadian centers. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03889249.

Correlation Between Magnitude of ST Segment Elevation and the Proximal Right Coronary Artery Lesion in Acute Inferior Myocardial Infarction

Introduction: The determination of the probable site of occlusion within RCA in acute inferior MI is very important because proximal occlusions are likely to cause greater myocardial damage and an early invasive strategy may be planned in such cases. Furthermore, identification of infarct-related artery and its site in acute inferior myocardial infarction not only guide decision regarding the urgency of revascularization but also guide to avoid therapy that may adversely affect the outcome. Objective: To predict the site of lesion in right coronary artery in acute inferior myocardial infarction by the magnitude of ST segment elevation in inferior leads (II, III and aVF). Methodology: This cross-sectional study was conducted in the Department of Cardiology, Sylhet MAG Osmani Medical College Hospital, from January 2014 to December 2015. A total of 50 consecutive patients with inferior MI who present within 12 hours of symptom onset and received fibrinolytic therapy were selected according to inclusion and exclusion criteria. Using 12-lead ECG, height of ST segment elevation in leads II, III and aVF were measured & coronary angiography(CAG) was performed during index hospital period .CAG which showed culprit lesion in RCA were only taken for the study. The sum of STsegment elevation in inferior leads were then correlated with the proximal lesion in RCA. Results: The age of the patients ranged from 31 to 70 years with the mean age of 51.1 (SD 9.2) years. Majorities (88%) of the patients were male and ratio of male to female was 7.33:1.Out of 50 patients, 26(52%) had the lesion in proximal, 19 (38%) in mid and 05 (10%) in distal RCA. Patients with proximal RCA lesion showed a mean ST segment elevation of 12.5(SD 1.07) mm, with mid RCA lesion 8.5 (SD 0.80) mm and distal RCA lesion 6.5(SD 0.42) mm. There was a positive correlation of sum of ST segment elevation in inferior leads II, III and aVF to the proximal lesion in RCA (r=0.923, P < 0.05). Conclusion: From the study it is concluded that the magnitude of ST segment elevation in inferior leads (II,III, aVF) can predict site of lesion in RCA in acute inferior wall myocardial infarction; the greater the sum of the height of ST segment elevation in inferior leads, the higher is the probability of lying the lesion in proximal right coronary artery. Bangladesh Heart Journal 2024; 39(1): 44-48

Recording maximal intercuspation and border positions of the mandible with intraoral scanner using the acquisition software's multi-occlusion function.

This in vitro study was conducted to investigate the accuracy of intraoral scanner (IOS) for recording maximal intercuspal position (MIP) and border positions of the mandible. Maxillary and mandibular master casts were articulated in MIP, protrusive, and lateral interocclusal position sequentially on a semi-adjustable articulator. For each articulation relation, sites of occlusal contacts (SOCs) and sites of clearance (SCs) were identified on the master casts with articulating paper (reference sites). IOS was used to take full arch scans and nine virtual interocclusal records (VIRs) for virtual articulation of models. Virtual SOCs and SCs were detected with 3D processing software and compared to those identified with the articulating paper. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each articulation relation. For MIP, IOS showed adequate sensitivity and NPV of 100%, and specificity and a PPV of 99%. For protrusive position, the IOS showed a sensitivity and a NPV of 100%, a high PPV of 86%, and a specificity of 83%. For lateral positions, the specificity and the PPV were high (93% and 79%, respectively), but the sensitivity and the NPV were below the clinically acceptable limits (28% and 56%, respectively). IOS displayed clinically acceptable accuracy for recording MIP and protrusive border mandibular position. However, IOS had less accuracy for lateral border mandibular position.

Evaluating the precision and accuracy of digital dental models with a low-cost structured light device.

This study evaluated the accuracy and precision of digital models acquisition using a home-built, low-cost scanning system based on the structured light method. a plaster model (PM) was scanned using the experimental device (SL) and a dental desktop scanner (DS). The teeth dimensions of PM and SL models were measured in triplicate, with a caliper and digitally, respectively. The agreement of the measurements of each model was evaluated using the intraclass correlation coefficient, and the validity between the different measurement techniques was assessed using the Bland-Altman analysis. The accuracy and precision of the models were qualitatively investigated using the mesh superposition of the SL and DS models. A high intraclass correlation coefficient was observed in all models (PM=0.964; SL1=0.998; SL2=0.995; SL3=0.998), and there was no statistical difference between the measurements of the SL models (p>0.05). PM and SL model measurements were found to be in good agreement, with only 3.57% of the observed differences between the same measurement being located outside 95% limits of agreement according to Bland and Altman (0.43 and -0.40 mm). In the superimpositions of SL-SL and SL-DS models, areas of discrepancy greater than 0.5 mm were observed mainly in interproximal, occlusal, and cervical sites. These results indicate that the home-built SL scanning system did not possess sufficient accuracy and precision for many clinical applications. However, the consistency in preserving the dental proportions suggests that the equipment can be used for planning, storage, and simple clinical purposes.

CT angiographic patterns predict carotid pseudo-occlusion in acute ischemic stroke.

Identifying carotid pseudo-occlusion (PO) from true occlusion (TO) has implications in determining the candidacy and feasibility of successful endovascular thrombectomy (EVT) in acute ischemic stroke (AIS). We reviewed the computed tomography angiographic (CTA) patterns differentiating a PO from a TO and analyzed the rate of successful recanalization after EVT. Patients with AIS and proximal internal carotid artery (ICA) occlusion who underwent EVT from 2014 to 2021 were identified. The patterns of carotid occlusion in CTA were classified into beak, dome, and flat patterns and correlated with microcatheter digital subtraction angiography (DSA) as PO and TO. The rates of successful recanalization in PO and TO were analyzed. Of the 24 patients, 16 (66%) had ICA PO and eight (33%) had TO in DSA. A beak pattern of the proximal ICA on CTA was significantly higher among the PO group patients (87.5% vs. 25%, P = 0.005), and a flat pattern was significantly higher among the TO group patients (50% vs. 12%, P = 0.005). A gradual contrast decline of the proximal ICA on CTA images was seen only in PO group patients (85.7% vs. 0%, P = 0.05). There was no significant difference in the rate of successful recanalization between PO and TO group patients (81.25% vs. 62.5%, P = 0.362). Beak pattern and gradual contrast decline at the proximal ICA occlusion site in CTA are suggestive of carotid PO. Identification of PO in CTA can help in planning intervention strategies and prognostication.

Postoperative blood glucose increase is associated with futile recanalization in patients with successful thrombectomy: a retrospective study

BackgroundTimely recognition of futile recanalization might enable a prompt response and an improved outcome in post-thrombectomy patients. This study aims to evaluate whether postoperative blood glucose increase (BGI) could act as an indicator of futile recanalization in patients receiving a successful thrombectomy.MethodsThis is a single-center, retrospective analysis of patients with anterior circulation large-vessel occlusion and successful thrombectomy between February 2019 and June 2022. BGI was defined as a higher level of blood glucose at the first postoperative morning than at admission. Futile recanalization was defined as patients with a modified Rankin Scale score of 3–6 at 90 days after onset. Multivariable binary logistic regression was used to assess the association of BGI with futile recanalization.ResultsA total of 276 patients were enrolled, amongst which 120 patients (43.5%) had BGI. Futile recanalization was more prevalent among patients with BGI compared to those without (70.0 vs. 49.4%, P = 0.001). After adjusting for potential confounders, BGI was associated with a higher likelihood of futile recanalization (adjusted OR: 2.97, 95%CI: 1.50–5.86, P = 0.002). This association was consistently observed regardless of diabetes history, occlusion site, time from symptom onset to groin puncture, or reperfusion status.ConclusionOur findings support BGI serving as an indicator of futile recanalization in patients with anterior circulation large-vessel occlusion and successful thrombectomy.

Percutaneous Transluminal Angioplasty (PTA) and Stent Implantation in Hemodialysis Patients with Central Venous Stenosis:A Study of Outcomes

BACKGROUND: Central venous stenosis and occlusion are serious complications that can arise from central venous catheterization in hemodialysis patients, leading to significant difficulties in the dialysis process. Common clinical manifestations include swelling in the arm or neck on the affected side and compromised hemodialysis access. To address this issue, percutaneous balloon angioplasty and stent implantation have emerged as potential solutions to maintain vein patency. However, there is a need to evaluate the efficacy of these interventions over an extended period to determine their long-term benefits. This study aimed to monitor the patency status periodically, starting at 1st Month, followed by assessments at 3rd Month, 6th Month, and finally, the 12th Month. METHODS: This single-center observational study focused on endovascular interventions performed on hemodialysis patients with central venous stenosis or occlusion.Participants included end-stage renal failure patients undergoing hemodialysis who exhibited clinical signs of central venous stenosis or occlusion. Data were collected from 60 patients, consisting of 42 males (70%) and 18 females (30%), with an average age of 46.19±13.21 years. The affected sites of central vein stenosis or occlusion were distributed as follows: 13 cases in the innominate veins, 25 cases in the superior vena cava, 18 cases in the brachiocephalic vein, and 10 cases in the subclavian vein. Some patients had multiple site occlusions, while others experienced occlusion of AV fistula. RESULTS: Of the 60 endovascular procedures performed, only one case did not achieve technical success, resulting in an overall success rate of 96.4%. Stent implantation was carried out in only four patients. No significant procedure-related complications were encountered, and all patients were able to undergo hemodialysis after the initial intervention. The primary patency rates for PTA at 1, 3, 6, and 12 months were 96%, 92%, 88%, and 86%, respectively. As for stent implantation, the primary patency rates at 1, 3, 6, and 12 months were 100%, 98%, 98%, and 98%, respectively. Assisted primary patency rates for PTA at 1, 3, 6, and 12 months were 2%, 6%, 11%, and 14%, respectively. During the 12-month follow-up, 10 reinterventions were performed, with three patients requiring more than two reinterventions. CONCLUSION: The study's findings demonstrate that endovascular interventions, such as percutaneous balloon angioplasty and stent implantation, are highly effective in managing central venous stenosis or occlusion in hemodialysis patients. These interventions showed a remarkable success rate and a minimal occurrence of procedure-related complications. Particularly, stent implantation consistently exhibited 100% primary patency at all evaluated time points. While the assisted primary patency rates for PTA were relatively lower, the overall need for reinterventions remained low, emphasizing the long-term benefits of these procedures. Based on these promising results, endovascular interventions can be considered as a viable and efficient option for the management of central venous stenosis or occlusion in hemodialysis patients, offering improved hemodialysis access and ensuring enhanced patient outcomes.

Evaluation of CINA® LVO artificial intelligence software for detection of large vessel occlusion in brain CT angiography

ObjectiveTo systematically evaluate the ability of the CINA® LVO software to detect large vessel occlusions eligible for mechanical thrombectomy on CTA using conventional neuroradiological assessment as gold standard. MethodsRetrospectively, two hundred consecutive patients referred for a brain CTA and two hundred patients that had been subject for endovascular thrombectomy, with an accessible preceding CTA, were assessed for large vessel occlusions (LVO) using the CINA® LVO software. The patients were sub-grouped by occlusion site. The original radiology report was used as ground truth and cases with disagreement were reassessed. Two-by-two tables were created and measures for LVO detection were calculated. ResultsA total of four-hundred patients were included; 221 LVOs were present in 215 patients (54 %). The overall specificity was high for LVOs in the anterior circulation (93 %). The overall sensitivity for LVOs in the anterior circulation was 54 % with the highest sensitivity for the M1 segment of the middle cerebral artery (87 %) and T-type internal carotid occlusions (84 %). The sensitivity was low for occlusions in the M2 segment of the middle cerebral artery (13 % and 0 % for proximal and distal M2 occlusions respectively) and in posterior circulation occlusions (0 %, not included in the intended use of the software). ConclusionsLVO detection sensitivity for the CINA® LVO software differs largely depending on the location of the occlusion, with low sensitivity for detection of some LVOs potentially eligible for mechanical thrombectomy. Further development of the software to increase sensitivity to all LVO locations would increase the clinical usefulness.

Induction of Acute Ischemic Stroke in Mice Using the Distal Middle Artery Occlusion Technique.

Ischemic stroke remains the predominant cause of mortality and functional impairment among the adult populations globally. Only a minority of ischemic stroke patients are eligible to receive intravascular thrombolysis or mechanical thrombectomy therapy within the optimal time window. Among those stroke survivors, around two-thirds suffer neurological dysfunctions over an extended period. Establishing a stable and repeatable experimental ischemic stroke model is extremely significant for further investigating the pathophysiological mechanisms and developing effective therapeutic strategies for ischemic stroke. The middle cerebral artery (MCA) represents the predominant location of ischemic stroke in humans, with the MCA occlusion serving as the frequently employed model of focal cerebral ischemia. In this protocol, we describe the methodology of establishing the distal MCA occlusion (dMCAO) model through transcranial electrocoagulation in C57BL/6 mice. Since the occlusion site is located at the cortical branch of MCA, this model generates a moderate infarcted lesion restricted to the cortex. Neurological behavioral and histopathological characterization have demonstrated visible motor dysfunction, neuron degeneration, and pronounced activation of microglia and astrocytes in this model. Thus, this dMCAO mouse model provides a valuable tool for investigating the ischemiastroke and worth of popularization.

Predicting 3-month Functional Outcome After Endovascular Thrombectomy in Patients with Anterior Circulation Occlusion with an Arterial Transit Artifact Grading System.

The objective of this study was to evaluate the relationship between arterial transit artifact (ATA), arterial spin labeling (ASL) perfusion imaging, and the outcome of patients with acute ischemic stroke (AIS) due to occlusion of large vessels in anterior circulation after endovascular thrombectomy (EVT). Patients with anterior circulation occlusion treated with EVT between October 2017 and December 2021 were enrolled in this retrospective study, and ATA was quantified by a4-point scale. Afavorable outcome was defined by modified Rankin Scale (mRS) scores of 0-2 at 3months. To identify independent predictors of favorable outcome, age, sex, risk factors, baseline National Institutes of Health Stroke Scale (NIHSS) score, site of occlusion, cause of stroke, and early reperfusion were evaluated with univariate and multivariate analyses. Predictive accuracy was evaluated by calculating the area under the receiver operating characteristic (ROC) curve (AUC) for the model. In this study 187 patients (age, 65.0 ± 12.5 years; men, 55%) were evaluated. Younger age (odds ratio, OR, 0.95; 95% confidence interval, CI, 0.92-0.98, p = 0.002), lower baseline NIHSS score (OR, 0.88; 95% CI, 0.82-0.94, p < 0.001), and lower ATA score (OR, 1.14; 95% CI, 1.06-1.22, p < 0.001) were independently associated with favorable outcomes in multivariate analysis. The ATA score has moderate to good accuracy in predicting favorable outcomes (AUC, 0.753). Ahigh ATA score as apotential predictor, can help identify patients who may benefit from EVT.

Stroke in a young adult: looking beyond the diffusion-weighted imaging sequence.

A 37-year-old migrainous woman was referred several hours after a sudden dysarthria lasting less than 1min. Brain MRI undertaken a few hours later showed no acute cerebral infarction on the diffusion-weighted imaging (DWI) sequence. However, an intraluminal thrombus within a distal branch of the middle cerebral artery (MCA) was seen on the T2*-weighted gradient echo images as well as hyperintense vessels related to slow flow beyond the occlusion's site. Control MRI 24h later confirmed the presence of a small infarct affecting the distal portion of the MCA territory but the thrombus was no longer visible. A comprehensive etiologic workup revealed the presence of a patent foramen ovale, as the underlying cause of the patient's stroke. Though the sensitivity of DWI sequence for acute ischemia is high, false negative exist particularly in cases of transient ischemic attack, brainstem or lacunar strokes. A careful brain MRI examination or the use of perfusion weighted imaging sequences are useful to avoid misdiagnosis particularly in young patients.

Predictive factors of poor outcome and mortality among anterior ischaemic stroke patients despite successful recanalisation in China: a secondary analysis of the CAPTURE trial

ObjectivesThis work aimed to analyse the risk factors for poor outcomes and mortality among patients with anterior large vessel occlusion (LVO) ischaemic stroke, despite successful recanalisation.Setting and participantsThis study conducted...

The Keller Plantation and the Racial Plot of Disability History in the U.S.

Between the popularization of Helen Keller’s autobiography, The Story of My Life (1903), and the cinematic dramatization of The Miracle Worker (1962), scenes of Keller’s early life and education have served as touchstones through which nondisabled Americans have imagined disability’s history and narrowed its political possibilities: toward the conditional dispersal of access based on individual acts of overcoming. Yet, if Keller’s story has played an outsize role in consolidating disability’s history and politics, it is also a site of profound racial occlusion. The context of Keller’s early life on the Keller plantation in Tuscumbia, Alabama is largely absent from her popular legacy. With the disappearance of this context, the black people who facilitated Keller’s disabled coming of age have also fallen away, as well as the history of slavery and Indigenous removal that made her life story possible. This void—at the locus of perhaps the most hegemonic origin story of American disability history—is cause for critical race inquiry. This essay traces the relationship between the material background of Keller’s autobiography and its imaginative foreground; from her family’s role in settler conquest and slavery in the Alabama Muscle Shoals, to Keller’s status as a transcendent icon of disability. Reading between the plantation and the plot of Keller’s Story while locating both beside the Tennessee River’s shoals, this essay turns to theories of cartography and narrative authored by Sylvia Wynter and Tiffany Lethabo King for insight into a critical paradox: the antiblack and anti-Indigenous structure of ableism, and the whiteness of disabled representation. By resituating Keller’s iconicity in relation to conquest, slavery, and their afterlives, this essay locates the problems and possibilities of narrating black and Indigenous disability history from the Keller plantation’s surround. Yet, while invested in unsettling the landscape, I neither recover these stories nor entomb them as untellable. Instead, I write toward further investment in black and Indigenous counter-archives that have complicated who has been—and who remains—the imaginable and politically traction-able subject of disability.

General anesthesia versus nongeneral anesthesia during endovascular therapy for acute ischemic stroke: A systematic review and meta-analysis.

This study compares the safety and efficacy of general anesthesia (GA) and nongeneral anesthesia (non-GA) on functional outcomes in patients receiving endovascular therapy for ischemic stroke. All available studies on the anesthetic management of patients with acute ischemic stroke in PubMed, the Cochrane Central Register of Controlled Trials, and Embase were included. We also compared the clinical outcomes in the studies with subgroup analyses of the occlusion site (anterior vs. posterior circulation) and preretriever group versus retriever group. Functional independence, mortality, successful recanalization, hemodynamic instability, intracerebral hemorrhage, and respiratory complications were considered primary or secondary outcomes. A total of 24,606 patients in 60 studies were included. GA had a lower risk of 90-day functional independence (OR=0.67, 95% CI 0.58 to 0.77), higher risk of 90-day mortality (OR=1.29; 95% CI 1.15 to 1.45), and successful reperfusion (OR=1.18; 95% CI 1.94 to 6.82). However, there were no differences in functional independence and mortality between GA and non-GA at 90 days after the procedure. The study shows poorer results in the GA group, which may be due to the inclusion of nonrandomized studies. However, analysis of the RCTs suggested that the outcomes do not differ between the two groups (GA vs. non-GA). Thus, general anesthesia is as safe as nongeneral anesthesia under standardized management.

Natural IgM Recognizing Oxidation-Specific Epitopes Attenuate NETosis Induced By Extracellular Vesicles

BACKGROUND Neutrophil extracellular traps (NETs) emerged as important contributors to thrombus formation. We have previously demonstrated the role of NETs in acute myocardial infarction (AMI). However, the mechanistic understanding of modulators of NETosis in the context of AMI is scarce. Levels of extracellular vesicles (EV) carrying lipid peroxidation-derived epitopes also called oxidation-specific epitopes (OSE), are increased at the culprit site in AMI. Importantly, natural IgM antibodies with specificity for OSE have been shown to inhibit the pro-coagulatory and pro-inflammatory effects of EV, and low plasma levels predict cardiovascular risk. We hypothesized that large EV, also called microvesicles (MV), induce NETosis during AMI, and that natural anti-OSE IgM are inhibiting this process. METHODS Patients were consented when the decision for primary percutaneous intervention (pPCI) for acute ST-segment elevation myocardial infarction (STEMI) was made, and blood was aspirated from the culprit site and peripheral site as an in-patient systemic control (n=28). Myocardial function was assessed by cardiac magnetic resonance imaging (cMRI) 4±2 days and 195±15 days after pPCI. EV were isolated from patient culprit site plasma and cell culture supernatants and characterized by flow cytometry. Isolated EV were used for neutrophil stimulation in vitro, and in vivo using a murine injection model in the presence of the IgM LR04 recognizing the immunodominant OSE, malondialdehyde (MDA) epitopes, or an isotype control. NETs were visualized by immunofluorescence staining for DNA-histone, citrullinated histone 3 (citH3) and myeloperoxidase (MPO). NET markers and natural IgM recognizing OSE in murine and patient plasma were measured by ELISA. RESULTS Culprit site plasma contained more and proportionally higher levels of leukocyte-derived CD45+ MDA-EV compared to the peripheral site plasma. NET markers were associated with CD45+ MDA-EV at the site of occlusion. Decreased levels of MDA-specific IgM at the culprit site indicated consumption of protective IgM. EV isolated from AMI patient plasma induced NETosis in vitro and after injection into C57BL/6 mice in vivo, as determined by NET markers and fluorescence microscopy of histone citrullination in neutrophils. The malondialdehyde-specific IgM LR04, but not a control IgM, reduced the NETogenic effects of EV in vitro and in vivo. Higher circulating levels of EV and lower OSE-IgM were associated with reduced ejection fraction in AMI patients at follow-up. CONCLUSION EV from AMI patients induced NET formation in vitro and in vivo, and natural IgM recognizing malondialdehyde-epitopes attenuated this effect. In summary, the balance between OSE-EV and OSE-IgM at the culprit site during AMI may represent a potential prognostic and therapeutic target. Moreover, the modulatory effect of natural IgM may also apply to other pathologies where NETosis contributes to thrombus formation.

Tenzing 7 delivery catheter with or without a leading microwire for single pass aspiration thrombectomy: A multicenter experience.

Aspiration mechanical thrombectomy traditionally includes use of an inner microcatheter and leading microwire to navigate an aspiration catheter (AC) to the site of occlusion. Early clinical experience suggests that a leading microwire is often not needed with the Tenzing 7 (T7, Route 92 Medical, San Mateo, CA), a soft tapered tip ledge-reducing delivery catheter. This multicenter experience aims to describe AC delivery success in single-pass thrombectomy using T7 with and without a leading microwire. A retrospective review was conducted of consecutive patients who underwent single-pass thrombectomy with T7 at six institutions between 2020 and 2022. We examined the percentage of successful AC delivery, puncture-to-revascularization time, and procedural complication rate. A leading microwire with T7 was used in 19/89 (21%) of patients, and it was not used with T7 in 70/89 (79%) of patients. Successful AC delivery was similar with and without microwires (97% vs. 90%, p = 0.15). Median puncture-to-revascularization times were similar (17 min microwire vs. 16 min no-microwire, p = 0.12). No complications were associated with microwire use; one (1.4%) patient had a T7-related vasospasm resolved with verapamil during thrombectomy without a leading microwire. Differences in complication rates were not statistically significant (p = 0.46). In our real-world clinical experience, leading microwire use was infrequently necessary with the T7 delivery catheter. Successful AC delivery and complication rates were similar with and without microwire use in single-pass T7 thrombectomies. Initial pass with T7 may be performed without use of leading microwire, reserving microwire use for refractory cases or known difficult-to-navigate vasculature.