Proximal Occlusion Research Articles

Endovascular treatment for M3 occlusions.

Endovascular treatment (ET) is a beneficial treatment for M1-2 occlusions of the middle cerebral artery. Mortality and disability rates are high if large vessel occlusions are not treated. While these rates are lower in M3 occlusions, important branch blockages can lead to disability. Endovascular treatment of small vessel occlusions is difficult, and there are no studies on the effectiveness of endovascular treatment for M3 occlusions. Accordingly, in this study, our aim was to assess the feasibility, safety, and preliminary efficacy of endovascular therapy for M3 occlusions. This study involved a retrospective analysis of a prospectively collected from two centres for acute ischemic stroke of the anterior system between July 2015 and April 2020. Demographic, radiologic, procedural and outcome variables were collected for patients who underwent endovascular therapy for acute ischemic stroke of the anterior system. Complete or near complete reperfusion (mTICI 2b-3) of the M3 occlusion was achieved in 15 cases (38.5%). Complete (mTICI 3) reperfusion was achieved in 24 cases (61.5%). Twenty-six patients were treated for primary M3 occlusion, while 13 patients with M3 occlusion were treated as a rescue strategy after successful treatment of a proximal greater vascular occlusion. Complete or near complete reperfusion (mTICI 2b-3) of primary occlusion was achieved in eight cases (30.8%), and complete (mTICI 3) reperfusion was achieved in 18 cases (69.2%). In addition, complete or near complete reperfusion (mTICI 2b-3) of rescue M3 occlusion was achieved in seven cases (%53.8), while complete (mTICI 3) reperfusion was achieved in six cases (46.2%). Only one patient with primary M3 occlusion had ICH due to extravasation. The patient's neurological examination one month later was normal. This retrospective study demonstrates that endovascular treatment of M3 occlusions is safe, effective and reliable.

Neutrophil-to-Lymphocyte Ratio Predicts Early Neurological Deterioration after Endovascular Treatment in Patients with Ischemic Stroke.

The worsening of neurological status that occurs early after acute ischemic stroke (AIS) remains a serious issue, and the inflammatory response plays a key role in stroke pathobiology. Recently, endovascular treatment (EVT) has revolutionized the management and outcome of patients with AIS due to either extracranial carotid disease or intracranial disease. The neutrophil-to-lymphocyte ratio (NLR) represents an easily available inflammatory biomarker. The aim of the study was to assess the relationship between the NLR at admission and the occurrence of early neurological deterioration (END) in patients with AIS who underwent EVT. Patients with AIS and proximal arterial occlusion in the anterior circulation undergoing EVT were retrospectively identified. Absolute neutrophil count (ANC) and absolute lymphocyte count (ALC) were collected from admission blood work to calculate the NLR. The study outcome was END defined as an increase in at least 4 points in NIHSS score or death between baseline and 24 h after the ischemic event. Patients included were 211, and END occurred in 30 (14.2%). Patients with older age (OR = 1.07, 95% CI: 1.02–1.13), higher serum glucose (OR = 1.01, 95% CI: 1.01–1.02), and higher NLR (OR = 1.011, 95% CI: 1.04–1.18) had an increased risk of END. The best predictive cut-off value of NLR was 6.4, and END occurred in 24.1% and 3.9% of the patients with NLR ≥ 6.4 and <6.4, respectively (p < 0.001). In patients with AIS undergoing EVT, higher NLR values predicted a higher risk of END. Biomarkers able to identify inflammatory mechanisms might identify novel treatment targets and enhance proof-of-concept trials of immunomodulation in stroke.

Endovascular Therapy of Tandem Occlusions: Baseline Characteristics and Outcomes Compared With Intracranial Occlusion

Background Endovascular therapy is highly effective in stroke caused by large vessel occlusion. Guidelines support treatment in case of occlusion of the intracranial internal carotid artery or the first segment of the middle cerebral artery. We aimed to examine baseline characteristics and outcome of patients who underwent endovascular therapy for tandem occlusions. Methods We conducted a retrospective study of patients who underwent endovascular therapy of tandem occlusion or occlusion of intracranial internal carotid artery/first segment of the middle cerebral artery between May 2015 and December 2019. Univariate comparisons of baseline characteristics and outcome (favorable functional outcome 90‐days after treatment and mortality) were performed. We used inverse‐probability‐of‐treatment‐weights to adjust for confounders. Results We compared 167 patients with tandem occlusion and 414 with intracranial occlusions. Patients with tandem occlusion were younger (69 years [interquartile range: 59.25–76] versus 74 [interquartile range: 64–81]; P = 0.0002), male (64.7% versus 51.4%; P = 0.004), more frequently active smokers (42.5% versus 25.6%; P = 0.0001), and less frequently subject to atrial fibrillation (18.6% versus 41.3%; P &lt;0.0001). No significant differences were seen in the rate of 90‐day good outcome (49.1% versus 51.0%; P = 0.68) or mortality (16.8% versus 18.1%; P = 0.70). This was also true after adjustment (relative risk for poor outcome 0.86 [95% CI: 0.72–1.05]). More proximal occlusions resulted in worse outcome in both tandem and intracranial occlusions. Conclusion Patients with tandem occlusion were more frequently younger, male smokers without atrial fibrillation illustrating the different risk factors underlying these strokes. Benefit from treatment was similar between groups, supporting endovascular therapy in tandem occlusions.

Algorithm for real-time analysis of intracoronary electrocardiogram

IntroductionSince its first implementation in 1985, intracoronary (ic) electrocardiogram (ECG) has shown ample evidence for its diagnostic value given the higher sensitivity for myocardial ischemia detection in comparison to surface ECG. However, a lack of online systems to quantitatively analyze icECG in real-time prevents its routine use. The present study aimed to develop and validate an autonomous icECG analyzing algorithm.Materials and methodsThis is a retrospective observational study in 100 patients with chronic coronary syndrome. From each patient, a non-ischemic as well as ischemic icECG at the end of a 1-min proximal coronary balloon occlusion was available. An ECG expert as well as the newly developed algorithm for autonomous icECG analysis measured the icECG ST-segment shift in mV for each icECG tracing.ResultsIntraclass correlation coefficient (ICC) demonstrated low variability between the two methods (ICC = 0.968). Using the time point of icECG recording as allocation reference for absent or present myocardial ischemia, ROC-analysis for ischemia detection by the manually determined icECG ST-segment shift showed an area under the curve (AUC) of 0.968 ± 0.021 (p < 0.0001). AUC for the algorithm analysis was 0.967 ± 0.023 (p < 0.0001; p = 0.925 for the difference between the ROC curve AUCs). Time to complete analysis was below 1,000 ms for the autonomous icECG analysis and above 5 min for manual analysis.ConclusionA newly developed autonomous icECG analysing algorithm detects myocardial ischemia with equal accuracy as manual ST-segment shift assessment. The algorithm provides the technical fundament for an analysing system to quantitatively obtain icECG in real-time.

Microstent for minimally invasive treatment of Fallopian tube occlusions – porcine implantation ex vivo

Abstract Involuntary female infertility represents a sensitive issue, which is frequently caused by an impaired patency of the Fallopian tube. Current treatment options, such as in vitro fertilisation (IVF) or tubal reconstruction, are related to high costs or surgical risks. Therefore, a need for an alternative highly safe and effective minimally invasive therapy option is assumed. The current work presents a proof-of-concept for a novel microstent in combination with a delivery system for treatment of proximal Fallopian tube occlusions. For this purpose, a microstent prototype was implanted into a porcine Fallopian tube ex vivo using the presented delivery system. The results of the procedure were analyzed using a micro-computed tomography (μ-CT). Based on the μ-CT imaging, critical parameters of the microstent, such as radial patency, were assessed. The microstent implantation leads to an increased opening area of the Fallopian tube. Additionally, the microstent does not impair the anatomical shape of the tube epithelium and adapts well to the anatomical path. In further studies, the functionality of the Fallopian tube will be examined after microstent implantation in vivo.

MR Angiography in Assessment of Collaterals in Patients with Acute Ischemic Stroke: A Comparative Analysis with Digital Subtraction Angiography.

Collateral status has prognostic and treatment implications in acute ischemic stroke (AIS) patients. Unlike CTA, grading collaterals on MRA is not well studied. We aimed to evaluate the accuracy of assessing collaterals on pretreatment MRA in AIS patients against DSA. AIS patients with anterior circulation proximal arterial occlusion with baseline MRA and subsequent endovascular treatment were included. MRA collaterals were evaluated by two neuroradiologists independently using the Tan and Maas scoring systems. DSA collaterals were evaluated by using the American Society of Interventional and Therapeutic Neuroradiology grading system and were used as the reference for comparative analysis against MRA. A total of 104 patients met the inclusion criteria (59 female, age (mean ± SD): 70.8 ± 18.1). The inter-rater agreement (k) for collateral scoring was 0.49, 95% CI 0.37–0.61 for the Tan score and 0.44, 95% CI 0.26–0.62 for the Maas score. Total number (%) of sufficient vs. insufficient collaterals based on DSA was 49 (47%) and 55 (53%) respectively. Using the Tan score, 45% of patients with sufficient collaterals and 64% with insufficient collaterals were correctly identified in comparison to DSA, resulting in a poor agreement (0.09, 95% CI 0.1–0.28). Using the Maas score, only 4% of patients with sufficient collaterals and 93% with insufficient collaterals were correctly identified against DSA, resulting in poor agreement (0.03, 95% CI 0.06–0.13). Pretreatment MRA in AIS patients has limited concordance with DSA when grading collaterals using the Tan and Maas scoring systems.

Restoring tubal patency with laparoscopic tubocornual anastomosis

ObjectiveTo assess the technical feasibility of laparoscopic tubocornual anastomosis (TCA) at restoring tubal patency in patients with proximal tubal occlusions. Materials and methodsA retrospective analysis of fourteen females with identified proximal tubal occlusions seeking to restore their tubal patency in a university-affiliated tertiary hospital between 2011 and 2018. Tubal patency within one year after the surgery was evaluated. ResultsThe patients had a mean age of 34.0 ± 3.6 years old, median parity of 1 child, and mean BMI of 23.0 ± 5.2 kg/m2. Of the fourteen patients, two (14.3%) received bilateral TCA, eight (57.1%) received only unilateral TCA, and four (28.6%) received TCA on one side and tubal anastomosis on the other. The operative time was 126.4 ± 37.9min for unilateral procedure and 201.0 ± 1.4 min for bilateral anastomoses. Postoperative hysterosalpingogram (HSG) demonstrated a patency rate of 64.2% at the TCA sites. Two ectopic pregnancies were reported thereafter. ConclusionThis preliminary series demonstrates that laparoscopic TCA is technically feasible and provides promising results for patients with proximal tubal occlusions hoping to restore their tubal function in order to conceive naturally. A larger prospective series is mandatory to establish its significance and application in clinical practices. Notably, infertile patients without surgically correctable factors are not suitable for this procedure.

P7.06: Endovascular Thrombectomy in a Chronic Upper Cava Syndrome Due to Long Term Home Parenteral Nutrition. New Hope to Extend Life Support

Introduction: Chronic Intestinal Pseudo Obstruction(CIPO) refers to a heterogeneous group of disorders characterized by symptoms of intestinal obstruction, without evidence of mechanical lesion and is a cause of chronic intestinal failure. Loss of vascular accesses by thrombosis has become the current main indication for intestinal transplant. Materials and Methods: A 28-year-old female patient with a history of myopathic CIPO received Home Parenteral Nutrition(HPN) for 25 years, developing central venous accesses thrombosis. As a consequence of a chronic upper cava syndrome with occlusion of the right jugular and subclavian-axillary vein, an invalidating headache and inability to maintain dorsal decubitus due to retroocular pain evolves overtime, but worsen with HPN infusion, limiting the volume and calories provided. A multidisciplinary case discussion concluded that although chronic, an endovascular thrombectomy should be attempted to improve quality of life and to satisfy nutritional needs. Results: A vascular computer tomography(CT) scan with 3D reconstruction and a digital venography were performed showing complete occlusion of the right jugular, axillary and subclavian(where a picc-line was placed as last access) veins and a partial occlusion of the proximal superior vena cava(SVC) and occlusion of the right iliac vein. An angioplasty trough the right humeral, axillary, innominate trunk axis and superior vena cava using 6 & 9mm balloons was performed. Balloon dilatation of multiple venous strictures was done, followed by placement of two stents, one into the right subclavian vein and SVC, and the other into left subclavian vein, with restitution of venous blood flow. Anticoagulation with Rivaroxaban and Clopidrogel was started. On the 5th postoperative day a new onset of acute pain, paresthesia were reported, followed by edema in the right upper limb. A Doppler ultrasound was positive for an acute thrombosis, confirmed by CT scan. A new phlebography and mechanical thrombectomy using the ASPIREX device followed by a new angioplasty of a partial distal stenosis was done. A new stent implantation into humeral, axillary, and subclavian veins was performed. Outcome was favorable with complete resolution of the symptoms; being discharged on day 6. The patient currently is asymptomatic, receiving HPN without complications. Conclusion: This case is an example of the management of deep venous thrombosis secondary to the chronic use of HPN. A comprehensive multidisciplinary approach is mandatory due to its complexity, requiring to be performed by trained and expert interventionists, to successfully provide new alternatives to extend the possibility for their life support or avoid contraindications to transplant. Peripheral venous hemodynamic is not a common procedure however, is the cornerstone to treat this complication achieving in many cases the recovery of venous blood flow delaying the need of intestinal transplantation.

The Hunter-8 Scale Prehospital Triage Workflow for Identification of Large Vessel Occlusion and Brain Haemorrhage

Objective The Hunter-8 prehospital stroke scale predicts large vessel occlusion in hyperacute ischemic stroke patients (LVO) at hospital admission. We wished to test its performance in the hands of paramedics as part of a prehospital triage algorithm. We aimed to determine (a) the proportion of patients identified by the Hunter-8 algorithm, receiving reperfusion therapies, (b) whether a call to stroke team improved this, and (c) performance for LVO detection using an expanded LVO definition. Methods A prehospital workflow combining pre-morbid functional status, time from symptom onset, and the Hunter-8 scale was implemented from July 2019. A telephone call to the stroke team was prompted for potential treatment candidates. Classic LVO was defined as a proximal middle cerebral artery (MCA-M1), terminal internal carotid artery, or tandem occlusion. Extended LVO added proximal MCA-M2 and basilar occlusions. Results From July 2019 to April 2021, there were 363 Hunter-8 activations, 320 analyzed: 181 (56.6%) had confirmed ischemic strokes, 13 (4.1%) transient ischemic attack, 91 (28.5%) stroke mimics, and 35 (10.9%) intracranial hemorrhage. Fifty-two patients (16.3%) received reperfusion therapies, 35 with Hunter-8 ≥ 8. The stroke doctor changed the final destination for 76 patients (23.7%), and five received reperfusion therapies. The AUCs for classic and extended LVO were 0.73 (95% CI 0.66–0.79) and 0.72 (95% CI 0.65–0.77), respectively. Conclusion The Hunter-8 workflow resulted in 28.7% of confirmed ischemic stroke patients receiving reperfusion therapies, with no secondary transfers to the comprehensive stroke center. The role of communication with stroke team needs to be further explored.

Ischemic Conditioning And Fatigability Of The Knee Extensors In Young And Older Adults

Aging is associated with impaired vascular function, reduced ability to generate muscular power, and increased limb fatigability (exercise-induced loss of power) for moderate- to high-velocity contractions. Ischemic conditioning is an intervention that can improve these areas of function in young adults and some diseased populations, yet its effects in older adults are unknown. PURPOSE: Determine the effect of ischemic conditioning on fatigability, power output, and exercising vascular function of the knee extensor muscles in young and older adults. METHODS: Knee extensor fatigability, power output, and vascular function were quantified in 10 young (23 ± 3 yr; 6f/4 m) and 11 older (74 ± 4 yr; 4f/7 m) adults after receiving ischemic conditioning (IC) and sham (SHAM) interventions on separate days. IC consisted of 4 sets of 5 min proximal thigh occlusion at 250 mmHg (20 mmHg for SHAM) with 5 minutes rest between sets. The fatiguing exercise consisted of 80 maximal-velocity contractions (1 contraction every 3-s) of the knee extensors lifting a load equivalent to 20% of the maximal voluntary isometric contraction. Superficial femoral artery blood flow was measured before and immediately after exercise using doppler ultrasonography. Muscle oxygenation (StO2) was measured during exercise with near-infrared spectroscopy. RESULTS: Fatigability (percent reduction in power) was not different between IC and SHAM in young (85 ± 12 v. 87 ± 8%) or older adults (70 ± 25 v. 70 ± 19%) [both p > 0.05], nor was power output at the start of the dynamic task in young (215 ± 55 v. 218 ± 60 W) or older adults (122 ± 45 v. 117 ± 46 W) [both p > 0.05]. Blood flow (% change pre- to post-exercise) did not differ between IC and SHAM in young (575 ± 96% v. 561 ± 87%) or older adults (404 ± 84% v. 380 ± 76%) [both p > 0.05]. StO2 was also not different between IC and SHAM in young (50 ± 10 v. 50 ± 8 A.U) or older adults (46 ± 5 v. 45 ± 7 A.U.) [both p > 0.05], nor was deoxy[heme] in young (24 ± 9 v. 24 ± 10 A.U.) or older adults (27 ± 8 v. 27 ± 5 A.U) [both p > 0.05]. CONCLUSIONS: Ischemic conditioning did not alter fatigability, power output, bulk blood flow, or oxygenation in the lower limb of young or older adults. These findings suggest ischemic conditioning is not an effective strategy for improving muscle or vascular function during high-velocity contractions in young and healthy older adults.

The Impact of a Modified Anaesthetic Protocol on Animal Survival and the Characteristics of Ventricular Arrhythmias in the Course of Acute Myocardial Infarction in a Domestic Pig Model.

Acute myocardial infarction (MI) is one of the most common causes of death in humans in highly developed countries. Among its most frequent complications affecting the patient's prognosis are cardiac arrhythmias: ventricular tachycardia (VT) and ventricular fibrillation (VF). The study aimed to characterise arrhythmias in 19 pigs subjected to experimentally induced MI obtained by occlusion of the proximal left anterior descending (LAD) coronary artery using an angioplasty balloon. The anaesthetic protocol was modified to reduce mortality by including procedures stabilising haemodynamic disorders which develop during episodes of ischaemia and arrhythmia. During 30 min of experimentally induced ischaemia, the heart rhythm was recorded using a 12-lead ECG. The time, frequency, and type of arrhythmias were analysed. Ventricular arrhythmias were found in 94.74% of the treated pigs. The most common were ventricular premature complexes, reported in 88.89% of pigs with arrhythmia. Ventricular tachycardia was recorded in 66.67% and ventricular fibrillation in 50% of pigs with arrhythmias. Myocardial infarction due to proximal LAD occlusion is characterised by a high incidence of ventricular arrhythmias, especially VT and VF. Because of the high survival rate, this MI porcine model may serve as a model for research on acute ischaemic ventricular arrhythmias in humans. Additionally, it reduces the total number of animals required for testing while yielding meaningful results, which is in line with the 3R principle.

Association of the Number of Embryos Transferred with Ectopic Pregnancy after Embryo Transfer in Patients with Salpingectomy or Proximal Tubal Occlusion

Background: With the prevalence of assisted reproductive technology (ART), the incidence of ectopic pregnancy (EP) is increasing, especially in patients with salpingectomy or proximal tubal occlusion. Methods: A total of 11,609 women who were undergoing ART and had undergone salpingectomy or proximal tubal occlusion, and 5388 women who achieved a clinical pregnancy were included in the study. Statistical analysis was used to determine whether the number of embryos transferred was associated with EP. Results: Both the number of embryos transferred and the day of embryo transfer differed significantly between those with and without EP (p &lt; 0.05), while the number of embryos transferred was associated with interstitial pregnancy (IP) (p &lt; 0.05) in those undergoing frozen-thawed embryo transfer (ET) cycles. Following multivariate modeling, the odds of having an EP in women undergoing frozen-thawed ET cycles increased with the number of embryos transferred (odds ratio [OR] 2.003, 95% confidence interval [95% CI] 1.036–3.876). Conclusions: The embryo transfer number was considered a risk factor for EP in patients undergoing frozen-thawed ET who had undergone salpingectomy or proximal tubal occlusion.

Prediction of need for bowel resection in acute superior mesenteric artery occlusion: A retrospective study of 48 Japanese patients.

This study aimed to predict cases of acute superior mesenteric artery (SMA) occlusion requiring bowel resection using occlusion site and time from symptom onset to diagnosis at five Japanese institutions. Advances in imaging, endovascular treatment, and perioperative management have improved the clinical outcomes of patients with acute SMA occlusion; however, in clinical practice it remains difficult to effectively determine patients requiring bowel resection. We retrospectively analyzed the data of 48 patients (mean age: 82.5y; male: 37.5%) diagnosed with acute SMA occlusion between June 2009 and August 2018. Background data of patients who required and did not require bowel resection were compared. A multivariable predictive model was developed using the time from symptom onset to diagnosis and whether SMA occlusion was proximal, including the origin of the middle colic artery. Fifteen patients (31.3%) died during the hospital stay. Atrial fibrillation (83.3%) was the most common comorbidity. The median time from symptom onset to diagnosis was 13.0 (interquartile range, 4.75-24.0) h. Laparotomy, bowel resection, and thrombus embolectomy were performed in 41 (85.4%), 26 (54.2%), and 21 (43.8%) patients, respectively. A logistic regression model achieved 78.6% sensitivity in predicting cases not requiring bowel resection. Proximal occlusion was significantly associated with the requirement for bowel resection (P=.039). The time from symptom onset to diagnosis and occlusion site contributed to high sensitivity in determining the need for bowel resection in patients with acute SMA occlusion. Further prospective studies are warranted to investigate the clinical impact of this model.

Optimizing the Definition of Ischemic Core in CT Perfusion: Influence of Infarct Growth and Tissue-Specific Thresholds.

CTP allows estimating ischemic core in patients with acute stroke. However, these estimations have limited accuracy compared with MR imaging. We studied the effect of applying WM- and GM-specific thresholds and analyzed the infarct growth from baseline imaging to reperfusion. This was a single-center cohort of consecutive patients (n = 113) with witnessed strokes due to proximal carotid territory occlusions with baseline CT perfusion, complete reperfusion, and follow-up DWI. We segmented GM and WM, coregistered CTP with DWI, and compared the accuracy of the different predictions for each voxel on DWI through receiver operating characteristic analysis. We assessed the yield of different relative CBF thresholds to predict the final infarct volume and an estimated infarct growth-corrected volume (subtracting the infarct growth from baseline imaging to complete reperfusion) for a single relative CBF threshold and GM- and WM-specific thresholds. The fixed threshold underestimated lesions in GM and overestimated them in WM. Double GM- and WM-specific thresholds of relative CBF were superior to fixed thresholds in predicting infarcted voxels. The closest estimations of the infarct on DWI were based on a relative CBF of 25% for a single threshold, 35% for GM, and 20% for WM, and they decreased when correcting for infarct growth: 20% for a single threshold, 25% for GM, and 15% for WM. The combination of 25% for GM and 15% for WM yielded the best prediction. GM- and WM-specific thresholds result in different estimations of ischemic core in CTP and increase the global accuracy. More restrictive thresholds better estimate the actual extent of the infarcted tissue.

CT vascular territory mapping: a novel method to identify large vessel occlusion collateral

IntroductionThis descriptive study explores typical patterns of vascular territory mapping (VTM) in ischaemic stroke patients with proximal vessel occlusion. VTM is a novel process using CT perfusion that can identify the source and extent of collateral blood flow in patients with vessel occlusion. It functions by determining which vessel provides dominant blood flow to a brain voxel.MethodsA total of 167 consecutive patients were analysed from INSPIRE (International Stroke Perfusion Imaging Registry) with their CT perfusion reprocessed through VTM software. We explored the typical territory maps generated by this software relating to common large vessel occlusion location sites (ACA/MCA/PCA).Results/ConclusionIn the presence of occlusion, VTM demonstrated a reciprocal increase in collateral vessel territories.

Effect of Intravenous Tirofiban vs Placebo Before Endovascular Thrombectomy on Functional Outcomes in Large Vessel Occlusion Stroke

Tirofiban is a highly selective nonpeptide antagonist of glycoprotein IIb/IIIa receptor, which reversibly inhibits platelet aggregation. It remains uncertain whether intravenous tirofiban is effective to improve functional outcomes for patients with large vessel occlusion ischemic stroke undergoing endovascular thrombectomy. To assess the efficacy and adverse events of intravenous tirofiban before endovascular thrombectomy for acute ischemic stroke secondary to large vessel occlusion. This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 55 hospitals in China, enrolling 948 patients with stroke and proximal intracranial large vessel occlusion presenting within 24 hours of time last known well. Recruitment took place between October 10, 2018, and October 31, 2021, with final follow-up on January 15, 2022. Participants received intravenous tirofiban (n = 463) or placebo (n = 485) prior to endovascular thrombectomy. The primary outcome was disability level at 90 days as measured by overall distribution of the modified Rankin Scale scores from 0 (no symptoms) to 6 (death). The primary safety outcome was the incidence of symptomatic intracranial hemorrhage within 48 hours. Among 948 patients randomized (mean age, 67 years; 391 [41.2%] women), 948 (100%) completed the trial. The median (IQR) 90-day modified Rankin Scale score in the tirofiban group vs placebo group was 3 (1-4) vs 3 (1-4). The adjusted common odds ratio for a lower level of disability with tirofiban vs placebo was 1.08 (95% CI, 0.86-1.36). Incidence of symptomatic intracranial hemorrhage was 9.7% in the tirofiban group vs 6.4% in the placebo group (difference, 3.3% [95% CI, -0.2% to 6.8%]). Among patients with large vessel occlusion acute ischemic stroke undergoing endovascular thrombectomy, treatment with intravenous tirofiban, compared with placebo, before endovascular therapy resulted in no significant difference in disability severity at 90 days. The findings do not support use of intravenous tirofiban before endovascular thrombectomy for acute ischemic stroke. Chinese Clinical Trial Registry Identifier: ChiCTR-IOR-17014167.

Plasma mid-regional pro-adrenomedullin: A biomarker of the ischemic penumbra in hyperacute stroke.

Reperfusion therapy has improved the outcomes of ischemic stroke but also emphasized the importance of ischemic penumbra. However, blood biomarkers are currently unavailable for this region. Adrenomedullin (ADM) is a neuroprotective peptide, secreted in a compensatory response to brain ischemia. We thus investigated whether an increase in mid-regional pro-ADM (MR-proADM), a stable peptide fragment of the ADM precursor, could act as a biomarker by predicting the ischemic penumbra in hyperacute ischemic stroke (HAIS). We prospectively enrolled consecutive HAIS patients (n=119; median age, 77 years; male, 59.7%) admitted to our institutes from July 2017 to March 2019 and evaluated plasma MR-proADM levels within 4.5h of onset. MR-proADM levels in HAIS were compared to healthy controls (n=1298; median age, 58 years; male, 33.2%) in the Japan Multi-Institutional Collaborative Cohort Study from 2013 to 2017. Furthermore, we evaluated whether MR-proADM levels were associated with the penumbra estimated by clinical-diffusion mismatch (CDM) (National Institute of Health Stroke Scale [NIHSS] ≥8, diffusion ischemic core volume ≤25 ml), or magnetic resonance angiography-diffusion-weighted imaging mismatch (MDM) (NIHSS ≥5, a proximal vessel occlusion with core volume ≤25 ml, or a proximal vessel stenosis/distal vessel occlusion with core volume ≤15 ml). In a case-control study, multivariate logistic analysis showed a significant association between HAIS and MR-proADM ≥0.54 nmol/L (adjusted odds ratio, 7.92 [95% CI, 4.17-15.02], p < 0.001). Though MR-proADM levels in HAIS did not correlate with the ischemic core volume (rs =0.09, p=0.348), they were higher in HAIS with CDM (n=34; 0.81 vs. 0.61 nmol/L, p < 0.001) or MDM (n=26; 0.83 vs. 0.62 nmol/L, p=0.002). These differences remained significant after adjusting baseline factors (adjusted odds ratio, 4.06 [95% CI, 1.31-12.55], p = 0.015 and 4.65 [1.35-16.11], p = 0.015, respectively). Plasma MR-proADM is elevated in HAIS, especially in those with a substantial penumbra, suggesting potential as a blood biomarker in this region.

Multicenter investigation of technical and clinical outcomes after thrombectomy for distal vessel occlusion by frontline technique

BackgroundEndovascular thrombectomy (EVT) is the standard-of-care for proximal large vessel occlusion (LVO) stroke. Data on technical and clinical outcomes in distal vessel occlusions (DVOs) remain limited.MethodsThis was a retrospective study...

Rule-based natural language processing for automation of stroke data extraction: a validation study.

Data extraction from radiology free-text reports is time consuming when performed manually. Recently, more automated extraction methods using natural language processing (NLP) are proposed. A previously developed rule-based NLP algorithm showed promise in its ability to extract stroke-related data from radiology reports. We aimed to externally validate the accuracy of CHARTextract, a rule-based NLP algorithm, to extract stroke-related data from free-text radiology reports. Free-text reports of CT angiography (CTA) and perfusion (CTP) studies of consecutive patients with acute ischemic stroke admitted to a regional stroke center for endovascular thrombectomy were analyzed from January 2015 to 2021. Stroke-related variables were manually extracted as reference standard from clinical reports, including proximal and distal anterior circulation occlusion, posterior circulation occlusion, presence of ischemia or hemorrhage, Alberta stroke program early CT score (ASPECTS), and collateral status. These variables were simultaneously extracted using a rule-based NLP algorithm. The NLP algorithm's accuracy, specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) were assessed. The NLP algorithm's accuracy was > 90% for identifying distal anterior occlusion, posterior circulation occlusion, hemorrhage, and ASPECTS. Accuracy was 85%, 74%, and 79% for proximal anterior circulation occlusion, presence of ischemia, and collateral status respectively. The algorithm confirmed the absence of variables from radiology reports with an 87-100% accuracy. Rule-based NLP has a moderate to good performance for stroke-related data extraction from free-text imaging reports. The algorithm's accuracy was affected by inconsistent report styles and lexicon among reporting radiologists.

Letter to the Editor: “Can I Afford to Become a Neurosurgeon in the United Kingdom in the Current Atmosphere?”

Cerebral revascularization strategies through extracranial to intracranial bypass have been adopted in the management of complex intracranial aneurysms. The internal maxillary artery used as a donor in a bypass is an effective method. At present, there are few quantitative analyses of cerebral blood flow perfusion. The main focus of this study was to evaluate the effectiveness of blood perfusion after bypass grafting.From April 2015 to December 2017, 19 patients who underwent internal maxillary artery radial artery middle cerebral artery bypass surgery with unobstructed bypass vessels were selected. Cerebral blood flow perfusion before and after bypass surgery was quantitatively evaluated by computed tomography perfusion imaging. The cerebral blood perfusion in the region of interest was measured by computed tomography perfusion.The aneurysms were excised after trapping in 2 cases with mass effects and neural compression. Proximal occlusion of the parent artery was performed in 9 cases of fusiform or giant dissecting aneurysms. Trapping was performed after bypass surgery in 8 cases. Within 3 months after surgery, 17 patients had good outcomes. After the hypothesis test, there was a significant difference between the preoperative △cerebral blood volume and postoperative △cerebral blood volume in the anterior area of the semioval center cross section (P = 0.001 < 0.05).The internal maxillary artery as a bypass donor is an effective method that can provide sufficient intracranial blood perfusion, and there is usually no cerebral ischemia in the surrounding area.