bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 020: Undulating Flow Velocities as an Induced Test of Autoregulation After Thrombectomy for Acute Ischemic Stroke
Authors: Mikkawi Aya , Alshaer Qasem N , Mohammaden Mahmoud , Haussen Diogo , Anderson Aaron 
Published: March 2024

Introduction
Loss of autoregulation after endovascular therapy (EVT) for large‐artery acute ischemic stroke (AIS) is well documented. [1] This might result in worse outcomes, despite successful recanalization, from hyper‐ or hypoperfusion with a risk for hemorrhagic conversion or larger stroke volume, respectively. Transcranial doppler (TCD) was previously used to document this phenomenon using spontaneous fluctuations in reactivity. Herein, we present a patient with suspected obstructive sleep apnea (OSA) with undulating flow velocities on TCD, serving as a test for induced vasoreactivity with pre‐ and post‐EVT TCD.

Methods
A case‐report.

Results
A middle‐aged patient was admitted with acute left cerebellar stroke (figure 1A). An Embolic etiology was suspected and a 20‐minuteTCD was done for spontaneous emboli detection on bilateral middle cerebral arteries (MCA). The patient fell asleep during the study and it incidentally revealed a bilaterally symmetric undulating velocity, which is a pattern that was previously described with OSA as a result of vasomotor response to multiple apnea and hypopnea episodes occurring in succession (Figure 1D – Pre‐EVT). [2] This pattern indicates intact vasomotor reactivity to fluctuating O2 and CO2 levels during episodes of apnea. Six days later, the patient developed acute right MCA stroke (Figure 1B) and was treated with EVT with successful reperfusion (TICI 2B67) (Figure 1C). TCD was repeated after EVT, and the previously seen undulating pattern was lost with significantly reduced variability on the right MCA compared to the contralateral side (figure 1E – Post‐EVT). This indicates a significant reduction in vasomotor reactivity and autoregulatory capacity of the right MCA. Follow up imaging revealed hemorrhagic conversion in the bed of the stroke with intraparenchymal bleeding (PH1) (Figures 1F‐H).
This case is unique since it provides an induced test of autoregulation and compares pre‐ and post‐EVT autoregulatory function. Prior reports did not use any stressors to test for autoregulation. While in this case, apnea served as a natural test for autoregulation allowing for easier detection. This can serve as a future marker that can be easily quantified and might guide post‐EVT care. Using breath holding maneuvers or medication (e.g., Acetazolamide) might be considered in the future to quantify the autoregulatory response. Further studies are required to investigate the utility of induced, instead of spontaneous, autoregulation assessment post‐EVT to guide blood pressure goals and the duration of strict blood pressure control after endovascular intervention.

Conclusion
Induced tests for autoregulation using TCD might be feasible and should be considered in the future as an easy method for quantifying autoregulation post‐EVT. Further studies are required to clarify the utility of this biomarker in guiding post‐EVT care.
Abstract 027: Adjunctive Intra‐Arterial Tenecteplase Following Mechanical Thrombectomy. (ALLY) Pilot Trial
Authors: Alhajala Hisham , Castonguay Alicia , Jumaa Mouhammad , Rao Rahul , Sheth Sunil , Oliver Marion , Burgess Richard , Jadhav Ashutosh , Haussen Diogo , Zaidat Osama O , Zaidi Syed Fazal 
Published: March 2024

Introduction
Intraarterial thrombolytic treatment after mechanical thrombectomy (MT) in patients with large vessel occlusion ischemic stroke may improve the odds of achieving complete reperfusion and favorable functional outcome at 90 days. This study evaluated the safety and efficacy of intraarterial Tenecteplase (IA TNK) as an adjunctive therapy to mechanical thrombectomy in patients with anterior circulation large vessel occlusion. The primary safety endpoint is the rate of symptomatic ICH within 24 hours of treatment with IA TNK. The primary efficacy endpoint is the proportion of patients with improvement of reperfusion. The secondary endpoints included final revascularization grade, discharge mortality, and any intracranial hemorrhage.

Methods
ALLY is a prospective, single‐center, single‐arm pilot study (ClinicalTrials.gov Identifier: NCT05172934). The study enrolled adult patients ≥18 and ≤85 years with large vessel (ICA or MCA) occlusion, with pre‐morbid mRS ≤3 who underwent mechanical thrombectomy and achieved incomplete reperfusion with a final TICI score of 2b and 2C. All enrolled subjects received at least one dose of 1.5 mg IA TNK. Additional treatments were administered at the discretion of the operator to a maximum of 4.5 mg IA TNK. Treatments were administered as a bolus in 3 divided doses given 5 minutes apart, with angiographic runs obtained before and after the final treatment. All patients had imaging follow up (MRI of CT) after 24 hours of treatment. Clinical assessment was completed with NIHSS and mRS scales. Angiographic and imaging data were adjudicated by an independent core laboratory.

Results
ALLY is a prospective, single‐center, single‐arm pilot study (ClinicalTrials.gov Identifier: NCT05172934). The study enrolled adult patients ≥18 and ≤85 years with large vessel (ICA or MCA) occlusion, with pre‐morbid mRS ≤3 who underwent mechanical thrombectomy and achieved incomplete reperfusion with a final TICI score of 2b and 2C. All enrolled subjects received at least one dose of 1.5 mg IA TNK. Additional treatments were administered at the discretion of the operator to a maximum of 4.5 mg IA TNK. Treatments were administered as a bolus in 3 divided doses given 5 minutes apart, with angiographic runs obtained before and after the final treatment. All patients had imaging follow up (MRI of CT) after 24 hours of treatment. Clinical assessment was completed with NIHSS and mRS scales. Angiographic and imaging data were adjudicated by an independent core laboratory.

Conclusion
Ally pilot study demonstrated that adjunctive intraarterial Tenecteplase to mechanical thrombectomy was safe and feasible without major complications. Although there was no change in final reperfusion TICI score, there was evidence of improved distal perfusion on angiographic images.
Abstract 031: Onyx versus nBCA in MMA Embolization for cSDH: A Single Center Experience of 234 hemispheres
Authors: Doheim Mohamed F , Kuybu Okkes , Salem Mohamed M , Ruiz Aldo Mendez , Fadhil Ali , Sultany Abdullah , Narayanan Sandra , Lang Michael , Al‐Bayati Alhamza , Nogueira Raul G , Gross Bradley 
Published: March 2024

Introduction
There is growing evidence supporting endovascular treatment with middle meningeal artery embolization (MMAE) for the treatment of chronic subdural hematoma (cSDH). We aimed to compare Onyx vs. N‐Butyl cyanoacrylate (n‐BCA) as liquid embolic materials for MMAE.

Methods
We included all eligible patients undergoing MMAE for cSDH at University of Pittsburgh Medical Center from April 2019 to December 2022. The main outcomes included radiographic resolution of cSDH with at least 50% reduction of hematoma thickness as a surrogate for treatment success in addition to the need for rescue surgical intervention. Additional outcomes including complication rates and hematoma thickness at the last available follow up.

Results
A total of 195 patients underwent embolization of 234 hemispheres including 39 bilateral procedures and had available data for final analysis (168 (71.8%) in Onyx group vs. 66 (28.2%) in n‐BCA group). There were no significant differences in age, sex, co‐morbidities, prior SDH/evacuation, pre‐operative cSDH thickness, or use of antithrombotic therapy(P>0.05) while concurrent surgical intervention and midline shift showed a statistically significant difference (P<0.05). On last follow‐up imaging, radiographical treatment success defined as ≥ 50% reduction in hematoma thickness was comparable in Onyx and the n‐BCA groups (50.9% vs 54.8%, P=0.6). Similarly, there was no statistically significant difference in the proportion of patients requiring rescue surgery between both groups (4.8% vs. 7.6%, P=0.4). Excluding concurrent surgical intervention patients yielded similar comparable results. Hematoma thickness at late follow‐up was not statistically significant between both group (8.25 (4.8‐12) mm vs 6.9 (3.1‐11) mm, P =0.11). There was no statistically significant difference in procedural complications between both groups (1.2% vs 1.5%, P=0.84).

Conclusion
Onyx and n‐BCA in MMAE seem to have comparable outcomes when used in the endovascular treatment of cSDH treatment. Further prospective studies with larger sample sizes are needed to confirm these findings.
Abstract 034: Value of Immediate Flat Panel Perfusion Imaging After Endovascular Therapy: A proof of concept study
Authors: Mujanovic Adnan , Kurmann Christoph , Manhart Michael , Piechowiak Eike , Pilgram‐Pastor Sara , Serrallach Bettina , Boulouis Gregoire , Meinel Thomas , Seiffge David , Jung Simon , Arnold Marcel , Nguyen Thanh , Fischer Urs , Gralla Jan , Dobrocky Tomas , Mordasini Pasquale , Kaesmacher Johannes 
Published: March 2024

Introduction
Clinical utility and diagnostic sensitivity of new‐generation flat‐panel computed tomography perfusion imaging (FPCTP) performed immediately after mechanical thrombectomy (MT) is unknown. We aimed to assess whether FPCTP obtained directly after MT could provide additional potentially relevant information on tissue reperfusion status.

Methods
Qualitative, single‐center analysis of all consecutive acute stroke patients admitted between 06/2019 and 03/2021 who underwent MT and post‐interventional FPCTP (n=26). A core‐lab blinded to technical details and clinical data performed reperfusion grading on post‐interventional digital subtraction angiography (DSA) images and time‐sensitive FPCTP maps. All patients were classified according to agreement between DSA and FPCTP.

Results
In 10/26 patients FPCTP revealed new, potentially clinically relevant information. Core‐lab adjudicated dichotomized detection of hypoperfusion (present/absent) was concurring in 21/26 (81%) patients. Of these, reperfusion findings showed perfect agreement on location and size in 16 (62%) patients, while in 5 (19%) patients with incomplete reperfusion, FPCTP showed additional hypoperfused areas missed on DSA. Of the remaining five patients subject to disagreement regarding the presence or absence of hypoperfusion, three showed complete reperfusion on DSA but hypoperfusion was noted on FPCTP, whereas two showed incomplete reperfusion on DSA without detectable hypoperfusion on FPCTP. FPCTP findings could have avoided Thrombolysis in Cerebral Infarction (TICI) overestimation in all false‐positive operator‐rated TICI3 cases.

Conclusion
In both core‐lab and real‐world operator assessment, FPCTP may provide additional clinically relevant information in a considerable percentage of patients undergoing MT. Hence, FPCTP may constitute a new standard for evaluating reperfusion efficacy and informed decision making in the angiography suite.
Abstract 035: Workflow Improvements from Automated LVO Detection Algorithms Are Dependent on Care Team Engagement
Authors: Azeem Hussain M 
Published: March 2024

Introduction
Automated machine learning (ML)‐based large vessel occlusion (LVO) detection algorithms have been shown to improve in‐hospital workflow metrics including door to groin time (DTG). The degree to which care team engagement and interaction are required for these benefits remains incompletely characterized.

Methods
This analysis was conducted as a pre‐planned post hoc analysis of our multicenter, prospective randomized clinical trial (NCT05838456). ML‐based LVO detection software was implemented at 4 comprehensive stroke centers in the greater Houston area in a stepped fashion between Jan 2021 and March 2022. Patients were included in this analysis if they underwent EVT for LVO AIS. Patients were excluded if they presented as inter‐hospital transfers or inpatient stroke alerts, as these workflows diverge considerably from ER‐based ones. ML‐software utilization quantified as the number of software interactions including imaging viewing and/or HIPAA‐compliant text messaging and was trichotomized at the hospital level into low/medium/high. Primary outcome was the reduction in DTG relation to pre‐ML implementation by hospital utilization level. Secondary outcomes included CT to groin puncture time, and sensitivity analyses in subsets of patients who did and did not have an LVO alert sent.

Results
Among 243 patients that met inclusion criteria, median age was 70 (IQR 58‐79), 50% were female and median NIHSS was 17 (IQR 11‐22). ML‐software utilization varied considerably with high‐utilization centers (n=2) interacting with mean 160 times, medium (n=1) 64 times and low center (n=1) 42 times during the study period. We observed a reduction on DTG of 11 minutes in the high‐interaction center (p<0.01) but no significant reduction in DTG in the medium or low‐interaction centers. Similarly, time from CT scan initiation to groin puncture fell in the high‐utilization centers by 32 minutes (p<0.05) but no significant change in others. Without adjusting for hospital‐level software utilization, there was no statistically significant reduction in DTG for patients analyzed by the ML software versus those that were not (p=0.35).

Conclusion
ML‐based workflow improvements are dependent on care team adoption and utilization.
Abstract 039: Angiographic Outcomes of Woven EndoBridge and Balloon‐Assisted Coiling for the Treatment of Ruptured Wide‐Necked Aneurysms
Authors: Calienes Aaron Rodriguez , Vivanco‐Suarez Juan , Galecio‐Castillo Milagros , Gross Bradley , Farooqui Mudassir , Algin Oktay , Feigen Chaim , Altschul David , Ortega‐Gutierrez Santiago 
Published: March 2024

Introduction
The optimal endovascular approach for wide‐neck intracranial aneurysms (IAs) during the acute phase of bleeding remains uncertain, and the use of stent‐assisted coiling or flow diversion is controversial due to antiplatelet therapy requirements and potential risks (1, 2). Various techniques have been developed to address these challenges, including balloon‐assisted coiling (BAC) and intrasaccular flow‐disruption. The Woven EndoBridge (WEB) is a flow disrupter that has gained popularity in treating ruptured IAs due to its effectiveness in occluding aneurysms with minimal rebleeding (3, 4). The aim of this study is to provide outcome comparisons between WEB and BAC in a specific cohort of patients with ruptured wide‐necked IAs.

Methods
In this international cohort study, we included consecutive patients treated for ruptured wide‐neck IAs with either WEB or BAC at three neurovascular centers. The primary effectiveness outcome was complete aneurysm occlusion at the final imaging follow‐up using the Raymond‐Roy (RR) occlusion classification. Secondary outcomes included favorable functional outcome and periprocedural hemorrhagic/ischemia‐related complications. Comparisons were performed using multivariable logistic and ordinal regressions.

Results
One hundred four patients treated with WEB and 107 patients treated with BAC were included. The mean length of imaging follow‐up was 17.5 (± 17.6) months in the WEB group and 11.8 (± 10.3) months in the BAC group (p = 0.142). Of the patients, 60.5% in the WEB group and 53% in the BAC group achieved complete occlusion, with no significant difference between the two groups after adjusting for covariates (adjusted OR [aOR] = 1.02; 95% CI 0.46 – 2.25; p = 0.964). The odds of favorable functional outcome did not significantly differ between the WEB (74.8%) and BAC groups (77.4%, aOR = 1.45; 95% CI 0.65 – 3.24; p = 0.368). Procedure‐related complications were similar in both groups (WEB: 9.6%, BAC: 10.3%, p = 0.872). There was no statistically significant difference observed in the rates of ischemic events (WEB: 6.7% vs. BAC: 2.8%, p = 0.180) and hemorrhagic events (WEB: 3.8% vs. BAC: 7.5%, p = 0.255) between the two groups.

Conclusion
In conclusion, both WEB and BAC techniques showed similar effectiveness and safety outcomes in treating ruptured wide‐neck IAs. Further research and direct comparative studies are needed to better guide treatment decisions for this patient population.
Abstract 048: The Tigertriever 13 for Primary Distal Vessel Occlusions (DVO) ‐ Multicenter Experience
Authors: Nordmeyer Hannes , Fischer Sebastian 
Published: March 2024

Introduction
Objective: To evaluate the safety and efficacy of the Tigertriever 13 stent retriever in acute ischemic stroke (AIS) patients with primary distal and medium vessel occlusions (DMVO). Tigertriever 13 is a low profile stentriever that enables using a small microcatheter for safer procedures.

Methods
This is a retrospective data analysis of consecutive 59 cases performed between 04/19‐12/22 in two German comprehensive stroke centers. These patients were either ineligible or failed thrombolysis.
Mean age was 75 and pre‐procedure NIHSS was 8,2 (SD 5,1), 55,9% Male, 37,2% were treated and failed thrombolysis treatment. These patients were admitted with disabling deficits that localize to the territory of the distal vessels. The occluded locations were 58,0% MCA M3, 0,0% MCA M4, 22,0% ACA, 20,0% PCA. All patients were treated with Tigertiever 13 with a mean of 1,7 passes where 100% under general anesthesia. Successful recanalization of the occluded vessel was measured by TICI score and intraoperative complications were recorded for safety evaluation.

Results
The mean time from symptoms onset to groin puncture was 200 minutes, and a successful recanalization rate of TICI 2b‐3 was observed in 72,8% of the patients while NIHSS was improved from 8,2 at baseline to 5,7 at discharge. There were 11,8% asymptomatic intracranial hemorrhages (ICH) and 0,5% symptomatic ICH.

Conclusion
The Tigertriever 13 device with operator controllability and high fluoroscopy visibility and its small size can potentially provide a safe and effective clot removal in patients with distal vessels occlusion. The effectiveness and safety profile in these patients with distal occlusions is comparable to those of patients with proximal occlusions.
Abstract 050: Intraarterial cooling combined with mechanical thrombectomy in acute stroke patients: systematic review and meta‐analysis
Authors: Eskian Mahsa , Miller Ronald , Sharashidze Vera , Heit Jeremy , Gould Grahame 
Published: March 2024

Introduction
Mechanical thrombectomy (MT) plays an important role in the treatment of intracranial large vessel occlusion (LVO) with recanalization success rate of 60%‐95%. Although the restoration of blood flow can ensue excess generation of reactive oxygen species (ROS) and inflammation which leads to cellular damage known as reperfusion injury. Recent studies have shown promising neuroprotection by reducing body temperature with the mechanism of limiting ROS and immune cells’ response. Although systemic hypothermia is associated with several adverse events and limited hypothermia affecting the specific ischemic brain tissue. Intra‐arterial cooling (IAC) combined with mechanical thrombectomy is a novel method for localized cooling.

Methods
Embase, and Web of Science were screened for English‐language papers including case reports/series, cohort studies and clinical trials. Studies were reviewed by 2 independent reviewers for inclusion criteria as patients with the age of >18 years old who had LVO and underwent mechanical thrombectomy combined with cold Saline infusion during mechanical thrombectomy (before or after recanalization). Statistical analyses were performed using R software version R‐4.3, P Value of <0.05 was considered significant.

Results
Four studies were included from initial 1177 studies, including 204 cases with MT combined with IAC (intra‐arterial 4°C saline infusion before or after recanalization) and 219 control with MT. Patients with MT+IAC had lower final infarct volume (MD=25, 95%CI [‐34.02, ‐15.98], P <0.0001), and better modified Rankin scale (mRS) after 90 days (RR=1.42, 95%CI [1.14, 1.77, P= 0.0015). There was no significant difference between MT+IAC and IAC group regarding deterioration of NIHSS in 24 hours(RR=1.09, 95%CI [0.42, 1.3, P=0.287), recanalization at 24 hours (RR=1.03, 95%CI [0.93, 1.14], P= 0.622), vascular spasm in 10 minutes (RR=2.90, , 95%CI [0.78, 10.80], P= 0.111), symptomatic intracranial hemorrhage (RR=0.78, 95%CI [0.48, 1.27], P= 0.322), coagulation abnormality (RR=0.94, , 95%CI [0.35, 2.54], P= 0.902), pneumonia (RR=1.09, 95%CI [0.79, 1.50], P= 0.585), and mortality in 90 days (RR=0.78, 95%CI [0.51, 1.20], P= 0.265).

Conclusion
Preliminary data is showing Intraarterial cooling combined with mechanical thrombectomy in acute stroke is a feasible and safe method for localized brain tissue cooling to prevent reperfusion injury and maximize long term outcome of MT.
Abstract 052: External Validation of the Prediction Model For Delayed Reperfusion in Patients with Incomplete Reperfusion: EXTEND‐PROCEED
Authors: Mujanovic Adnan , Ng Felix , Branca Mattia , Meinel Thomas , Churilov Leonid , Mitchell Peter , Yassi Nawaf , Parsons Mark , Sharma Gagan , Arnold Marcel , Piechowiak Eike , Kleinig Timothy , Seiffge David , Dobrocky Tomas , Gralla Jan , Fischer Urs , Campbell Bruce , Kaesmacher Johannes 
Published: March 2024

Introduction
The benefit of additional reperfusion attempts in patients with partial angiographic reperfusion (TICI2b) is unknown. The PROCEED model predicts subsequent favorable occurrence of complete reperfusion (i.e. delayed reperfusion [DR]) at 24 hours after initial incomplete angiographic reperfusion at the conclusion of thrombectomy. This study aims to externally validate the PROCEED model using pooled data from multiple international trials that systematically performed follow‐up perfusion imaging.

Methods
Individual patient data for external validation were obtained from the EXTEND‐IA, EXTEND‐IA TNK part 1 and 2 trials (clinicaltrials.gov, unique‐identifier: NCT01492725, NCT02388061 and NCT03340493). The model’s primary outcome of interest was the occurrence of DR, defined as the absence of any focal perfusion deficit on follow‐up CT or MRI perfusion imaging maps, despite initial incomplete angiographic reperfusion on the final thrombectomy angiography series. The updated model’s performance was evaluated with discrimination, calibration and clinical decision curves.

Results
We analyzed 267 patients for the external validation, with median age of 74 (IQR 64 – 80), 44.2% were female and 62% had DR. The externally validated model had good discrimination (C‐statistic 0.81, 95% CI 0.72 – 0.86) and was well calibrated (intercept 0.22, 95% CI 0.18‐0.33 and slope 0.96, 95% CI 0.81‐1.23). With threshold probability of R=12% (i.e. 88% chance of having DR), pursuing additional reperfusion attempts to pursue complete angiographic reperfusion in a patient with high‐likelihood of DR were seven times worse (Cost:Benefit Ratio 1:7, Figure 1) than no further endovascular maneuver. In terms of standardized net reduction, the PROCEED model could reduce one in five unnecessary interventions without missing an intervention for any patient who would eventually have DR. Across a wide range of threshold probabilities, the model outperformed the scenario of the typical decision‐making process in the angiography suite, based on the current treatment guidelines.

Conclusion
The externally validated model had good predictive accuracy and discrimination. Depending on the acceptable risk threshold, the model may compliment clinical judgment of the treating physicians and inform on natural progression of untreated incomplete reperfusion.