Impact of Aortic Arch Anatomy on Technical Performance and Clinical Outcomes in Patients with Acute Ischemic Stroke

Separation of left internal and external carotid arteries via right brachial artery approach in cerebral angiography

Cerebral angiography is essential for diagnosing cerebrovascular diseases and crucial to separate the internal and external carotid arteries during angiography. The femoral artery approach is more invasive than the brachial artery approach. In some cases, guiding the catheter through the right brachial artery to the left internal and external carotid arteries is feasible. This study retrospectively investigated factors influencing successful catheter guidance to the left carotid arteries. We studied 30 patients (17 men; mean age 64.9 years) in whom catheter guidance to the left internal and external carotid arteries was attempted via the right brachial artery. A 4Fr Simmons-type catheter and a 0.035-inch diameter guidewire were used. We retrospectively analyzed patient characteristics and aortic arch anatomy. Guidance was successful in 20 patients (66.7%). There were no significant differences in sex, age, height, weight, BMI, aorta type, or bifurcation type between the brachiocephalic and left common carotid arteries between the successful and unsuccessful cases. However, a significant difference was observed in the angle formed by the Simmons catheter during insertion into the left common carotid artery (45.7° vs 19.3° p < .01). The rising angles of the catheter entering the aortic arch from the brachiocephalic artery were 64.2° versus 84.8°, respectively (p < .01). Cut-off values were 30.9° (AUC = 0.985) and 77.5° (AUC = 0.9). Safe guidance to the left internal and external carotid arteries was achievable when the angle of the Simmons catheter curve was 30.9° or greater and the rising angle of the catheter entering the aortic arch from the brachiocephalic artery was 77.5° or less.

Deep learning-based model for difficult transfemoral access prediction compared with human assessment in stroke thrombectomy

BACKGROUND

In mechanical thrombectomy (MT), extracranial vascular tortuosity is among the main determinants of procedure duration and success. Currently, no rapid and reliable method exists to identify the anatomical features precluding fast and stable access to the cervical vessels.

METHODS

A retrospective sample of 513 patients were included in this study. Patients underwent first-line transfemoral MT following anterior circulation large vessel occlusion stroke. Difficult transfemoral access (DTFA) was defined as impossible common carotid catheterization or time from groin puncture to first carotid angiogram >30 min. A machine learning model based on 29 anatomical features automatically extracted from head-and-neck computed tomography angiography (CTA) was developed to predict DTFA. Three experienced raters independently assessed the likelihood of DTFA on a reduced cohort of 116 cases using a Likert scale as benchmark for the model, using preprocedural CTA as well as automatic 3D vascular segmentation separately.

RESULTS

Among the study population, 11.5% of procedures (59/513) presented DTFA. Six different features from the aortic, supra-aortic, and cervical regions were included in the model. Cross-validation resulted in an area under the receiver operating characteristic (AUROC) curve of 0.76 (95% CI 0.75 to 0.76) for DTFA prediction, with high sensitivity for impossible access identification (0.90, 95% CI 0.81 to 0.94). The model outperformed human assessment in the reduced cohort [F1-score (95% CI) by experts with CTA: 0.43 (0.37 to 0.50); experts with 3D segmentation: 0.50 (0.46 to 0.54); and model: 0.70 (0.65 to 0.75)].

CONCLUSIONS

A fully automatic model for DTFA prediction was developed and validated. The presented method improved expert assessment of difficult access prediction in stroke MT. Derived information could be used to guide decisions regarding arterial access for MT.

ACCESS: ACtive Catheterization for EndovaScular TreatmentS-A First-in-Human, Single-Center, Nonrandomized, Open Clinical Study of the G60 Active Device for Endovascular Neurointerventions

The catheterization of supra-aortic vessels during neuroendovascular interventions may be challenging in the setting of complex aortic arch anatomy. Evaluation of a new mechatronic controllable directional device in conjunction with different sheath and guide catheters to ease the cannulation of the supra-aortic vessels was conducted in the setting of a first-in-human clinical study. The evaluation assessment included access to the aortic arch, the technical success of the device in terms of time to target vessel, target vessel catheterization, adverse events, and clinical outcome. Ten subjects were enrolled at 1 site for treatment. Successful access, target vessel catheterization, and correct positioning of the catheter into the target vessel with the G60 device were achieved for all 10 procedures (7 from femoral access, 3 from radial access). One procedural complication, unrelated to the G60 device, was recorded during the investigation. The G60 is a polyvalent active device that facilitates guide catheter navigation in neuroendovascular interventions.

A thoracic CT imaging parameter predicting access difficulty in acute stroke thrombectomy

PURPOSE

The quick establishment of adequate vascular access is essential for the technical success of mechanical thrombectomy (MT). Focusing on shifts in aortic arch geometry and aging-related changes, we propose an imaging parameter for predicting access difficulty using chest CT.

METHODS

Patients with acute anterior circulation large-vessel occlusion who underwent MT from April 2020 to September 2021 were included in this retrospective multicenter observational study. The distance from the sternum to the ascending aorta (S-AAD) was defined as the surrogate marker of access difficulty. Access was defined as difficult when the time from femoral sheath placement to guiding catheter induction (guiding time: GT) ≥ 30 minutes, and the patients were dichotomized into groups with short GT (sGT: GT < 30 min) and long GT (lGT: GT ≥ 30 min).

RESULTS

One hundred fifteen patients were included. There were 12 patients (10.4 %) in lGT group. The median (IQR) S-AAD was 11.9 mm (6.3, 18.3 mm) in sGT group and 6.6 mm (4.0, 10.3 mm) in lGT group, and a significant difference in S-AAD was observed (P = 0.026). In multivariate analyses, dyslipidemia and S-AAD < 5 mm were significantly associated with difficult access (OR, 5.938 [95 % CI, 1.468, 24.022], P = 0.012 for dyslipidemia; OR, 5.147 [95 % CI, 1.267, 20.917], P = 0.022 for S-AAD < 5 mm).

CONCLUSION

S-AAD is a simple and reliable imaging parameter to predict access difficulty. This parameter may be helpful in selecting the appropriate devices and access routes in preinterventional practice.

An in-vitro method for comparative analysis of aspiration catheter tracking performance

BACKGROUND AND PURPOSE

Mechanical thrombectomy (MT) for acute ischemic stroke (AIS) relies on efficient tracking of aspiration catheters through complex vascular anatomies. Differences in catheter design lead to variation in tracking performance which may only become apparent after use in patients. We developed an in-vitro methodology for evaluating aspiration catheter performance under a variety of pre-defined circumstances, that can be used during catheter development for design optimization.

METHODS

Validation of the in-vitro methodology involved testing four large bore aspiration catheters on recreated challenging vascular access routes derived from patient angiograms. Two experienced neurointerventionalists conducted the tests under controlled physiological and procedural conditions. Each catheter design was evaluated across 30 unique anatomy-procedural set-up combinations. A fifth, prototype large bore catheter was evaluated by trained engineers to assess the applicability of the in-vitro test.

RESULTS

Results from statistical analysis using a general linear model demonstrated the methodology's effectiveness in detecting significant tracking differences among catheter designs (p < 0.01). Minimal inter-operator variability was observed (p = 0.304), while procedural techniques significantly influenced tracking performance (p < 0.01). The tortuosity of the arterial access route notably impacted catheter performance (p < 0.01), with anatomical features revealing varying degrees of influence on desirable and undesirable catheter design aspects.

CONCLUSION

We successfully developed a test methodology for evaluating the trackability of large bore aspiration catheters intended for treating acute ischemic stroke with large vessel occlusions. This methodology offers a robust approach to pre-clinical design assessment, utilizing anatomical models that simulate real-world vascular challenges to enhance catheter optimization.

Factors Affecting Compression of the Left Subclavian Artery Bridging Stent In Zone 2 Fenestrated Endovascular Arch Repair

INTRODUCTION

Left subclavian artery (LSA) preservation during thoracic endovascular aortic repair (TEVAR) has been related to low morbidity. This study investigated the incidence of LSA stent compression in patients managed with fenestrated endovascular arch repair (f-Arch) and evaluated the impact of anatomic and technical factors on LSA stent outcomes.

METHODS

A single-center retrospective analysis of patients managed with single-fenestration devices (Cook Medical, Bloomington, IN, USA) for LSA preservation, between January 1, 2012 and November 30, 2023, was conducted. Anatomic (arch type, bovine arch, distance between the LSA and most proximal bone structure, left common carotid artery and aortic lesion, take-off angle, diameter, thrombus, calcification, dissection, tortuosity) and technical parameters (stent type, diameter, length, relining, post-dilation) were evaluated. Stent compression was any ≥50% stenosis (using center luminal line) of the stent compared with its initial diameter. Clinical outcomes included stroke and upper limb ischemia at 30 days and follow-up. Technical outcomes included stent compression and need for reintervention.

RESULTS

Fifty-four cases were included. Only balloon-expandable covered stents were used, and relining during the index procedure was performed in 18%. No stroke or arm ischemia was recorded. One stent compression was detected at 30 days. During follow-up, no stroke or arm ischemia was diagnosed. Nine cases (18%) presented stent compression, with a mean time of stent-compression diagnosis at 18 months (interquartile range [IQR]=37, range=1-58 months) after the index procedure. Five (56%) underwent secondary relining. Follow-up after reintervention was uneventful. Lower distance to the nearest bone structure (compression group [CG]: 11.7±8.9 mm vs non-compression group [NCG]: 23.0±7.8 mm, p=0.003) and higher tortuosity index (CG: 1.3±0.4 vs NCG: 1.2±0.1, p=0.03) were associated with LSA stent compression.

CONCLUSION

LSA stent compression in patients managed with f-Arch affected 1 in 5 cases, without clinical consequences. Distance to the nearest bone structure and higher tortuosity were associated with LSA stent compression.

CLINICAL IMPACT

Fenestrated endovascular arch repair for the preservation of the left subclavian artery (LSA) in patients needing landing within the aortic arch has been performed with encouraging outcomes. This analysis showed that LSA stent compression is met in 18% of patients, without though any clinical consequence. Pre-operative anatomic parameters, as lower distance to the nearest bone structure and higher tortuosity index affect negatively LSA stent performance while stent parameters seem to have no impact.

Mechanical thrombectomy for treatment of acute ischemic stroke in frail patients: a systematic review of the literature

BACKGROUND

The overall safety and efficacy of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) in frail patients is not well delineated. This systematic review aims to summarize and compare outcomes in frail and non-frail patients who underwent MT for AIS.

METHODS

A systematic review of the literature was performed using PubMed, Ovid Medline, and Web of Science to identify studies with outcomes-related data for frail patients with MT-treated AIS. The recanalization rate, procedural complications, and clinical outcome at 90-day follow-up were collected.

RESULTS

In the four included studies there were 642 frail patients and 499 non-frail patients. Frail patients had reduced rates of good functional outcomes (29% vs 42%; χ2=22, p<0.01) and increased 90-day mortality (51% vs 25%; χ2=38, p<0.01) compared with non-frail patients.

CONCLUSION

MT for treatment of AIS in frail patients may be associated with worse rates of morbidity and mortality along with reduced efficacy. Given that no studies to date directly compare conservative measures with endovascular management for AIS in frail patients, more studies are required to further evaluate and identify characteristics that may improve outcomes in these patients.

Systematic Review and Meta-analysis of Radial or Femoral Access for Carotid Stenting

PURPOSE

There is a growing interest in performing coronary artery and neurovascular interventions via the radial artery; however, few studies have examined the outcomes of transradial carotid stenting. Therefore, our study aimed to compare cerebrovascular outcomes and crossover rates in carotid stenting between transradial and traditional transfemoral approaches.

METHODS

A systematic review was performed by searching three electronic databases from inception to June 2022 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. In addition, random effect meta-analysis was used to pool the odds ratios (ORs) for stroke, transient ischemic attack, major adverse cardiac events, death, major vascular access site complications, and procedure crossover rates between the transradial and transfemoral approaches.

RESULTS

A total of 6 studies were included involving a total of n = 567 transradial and n = 6176 transfemoral procedures. The ORs for stroke, transient ischemic attack, and major adverse cardiac events were 1.43 (95% confidence interval, CI 0.72-2.86, I2 = 0), 0.51 (95% CI 0.17-1.54, I2 = 0), and 1.08 (95% CI 0.62-1.86, I2 = 0), respectively. Neither the major vascular access site complication rate (OR 1.11, 95% CI 0.32-3.87, I2 = 0) nor crossover rate (OR 3.94, 95% CI 0.62-25.11, I2 = 57%) showed statistically significant differences between the two approaches.

CONCLUSION

The modest quality of the data suggested comparable procedural outcomes between the transradial and transfemoral approaches when performing carotid stenting; however, high level evidence regarding postoperative brain images and risk of stroke in transradial carotid stenting are lacking. Therefore, it is reasonable for interventionists to weigh up the risks of neurological events and potential benefits, including fewer access site complications, before choosing the radial or femoral arteries as access sites. Future large-scale randomized controlled trials are imperative.

Crossover from Femoral to Radial Access During Mechanical Thrombectomy of Large Vessel Occlusion Stroke

BACKGROUND

Challenging arterial anatomy may prevent timely endovascular treatment (EVT) of acute ischemic stroke (AIS) through a transfemoral approach prompting the use of alternative access routes. We determined the crossover rate from femoral to radial access during EVT of AIS due to large vessel occlusion and identified its radiological predictors and clinical outcomes.

MATERIALS AND METHODS

Retrospective review of all AIS patients who underwent EVT at a single institution from January 2016 to March 2021 was performed. A primary and a secondary radial group depending on whether the radial approach was used primarily or secondary to failure of transfemoral approach were compared.

RESULTS

A total of 358 consecutive AIS patients with large vessel occlusion underwent EVT. Radial approach was used primarily in 6 patients (primary radial [PR]) and secondarily in 16 patients (secondary radial [SR]). The rate of femoral to radial crossover was 4.7%. Type III arch and bovine arch configurations were the most common characteristic in the crossover group. Radial access was successful to secure intracranial access in all cases of PR and in 87% of crossover cases. There was no significant difference between the rates of successful reperfusion (53.3% SR, 83% PR, P = 0.20), National Institutes of Health Stroke Scale score on discharge (19 SR, 18 PR group, P = 0.90), or good outcome defined as modified Rankin Scale score 0-2 (13.3% SR, 33.3% PR, P = 0.29).

CONCLUSIONS

A radial approach can be considered during EVT of AIS due to large vessel occlusion either primarily or secondarily with a lower threshold to switch from the femoral approach in cases of challenging anatomy.

Deep Learning-based Assessment of Internal Carotid Artery Anatomy to Predict Difficult Intracranial Access in Endovascular Recanalization of Acute Ischemic Stroke

BACKGROUND

Endovascular thrombectomy (EVT) duration is an important predictor for neurological outcome. Recently it was shown that an angle of ≤ 90° of the internal carotid artery (ICA) is predictive for longer EVT duration. As manual angle measurement is not trivial and time-consuming, deep learning (DL) could help identifying difficult EVT cases in advance.

METHODS

We included 379 CT angiographies (CTA) of patients who underwent EVT between January 2016 and December 2020. Manual segmentation of 121 CTAs was performed for the aortic arch, common carotid artery (CCA) and ICA. These were used to train a nnUNet. The remaining 258 CTAs were segmented using the trained nnUNet with manual verification afterwards. Angles of left and right ICAs were measured resulting in two classes: acute angle ≤ 90° and > 90°. The segmentations together with angle measurements were used to train a convolutional neural network (CNN) determining the ICA angle. The performance was evaluated using Dice scores. The classification was evaluated using AUC and accuracy. Associations of ICA angle and procedural times was explored using median and Whitney‑U test.

RESULTS

Median EVT duration for cases with ICA angle > 90° was 48 min and with ≤ 90° was 64 min (p = 0.001). Segmentation evaluation showed Dice scores of 0.94 for the aorta and 0.86 for CCA/ICA, respectively. Evaluation of ICA angle determination resulted in an AUC of 0.92 and accuracy of 0.85.

CONCLUSION

The association between ICA angle and EVT duration could be verified and a DL-based method for semi-automatic assessment with the potential for full automation was developed. More anatomical features of interest could be examined in a similar fashion.

Transcarotid versus transfemoral access for cerebrovascular intervention: protocol for a systematic review and meta-analysis

INTRODUCTION

Cerebrovascular intervention is an excellent option to treat cerebrovascular diseases. Interventional access is a prerequisite and a foundation for cerebrovascular intervention, which is crucial to the success of an intervention. Although transfemoral arterial access (TFA) has become a popular and acceptable method of access for cerebrovascular angiography and intervention in clinical practice, it has some drawbacks that limit the usage in cerebrovascular interventions. Therefore, transcarotid arterial access (TCA) has been developed in cerebrovascular interventions. We aim to conduct a systematic review to compare the safety and efficacy of TCA with TFA for cerebrovascular intervention.

METHODS AND ANALYSIS

In this protocol, Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols were followed. PubMed, Embase, Web of Science and the Cochrane Central Register of Controlled Trials will be searched mainly from 1 January 2004, to the formal search date. Additionally, reference lists and clinical trial registries will be searched. We will include clinical trials with more than 30 participants, which reported the endpoints of stroke, death and myocardial infarction. Two investigators will independently select studies, extract data and assess bias risk. A standardised mean difference with 95% CI will be presented for continuous data, and a risk ratio with 95% CI will be presented for dichotomous data. On inclusion of sufficient studies, subgroup analysis and sensitivity analysis will be conducted. The funnel plot and Egger's test will be used to assess publication bias.

ETHICS AND DISSEMINATION

As only published sources will be used in this review, ethical approval is not required. We will publish the results in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42022316468.

Balloon Gliding Technique: A novel use of balloon guiding catheters in accessing challenging circulations when treating acute ischemic stroke

BACKGROUND

Challenging arterial anatomy delays, or prevents timely endovascular treatment (EVT) of acute ischemic stroke (AIS). We introduce a new technique called 'Balloon Gliding Technique (BGT)' to overcome difficult arterial anatomy during EVT of AIS, utilizing flow-assistance to access challenging circulations.

METHODS

Retrospective review of a prospectively collected database of all patients presenting to a single institution with AIS who underwent EVT was performed from January 2021 to June 2021. Patients in whom BGT was performed were assessed. BGT consists of advancing the balloon guide catheter in the cervical carotid artery while its balloon is inflated, and therefore carried by downstream flow.

RESULTS

Of 51 patients presenting with AIS secondary to large vessel occlusion during the study period, five patients underwent BGT. All five patients had anterior circulation large vessel occlusions. Mean age of the BGT patients was 92.2 years, and all patients were females. A type 3 arch was present in all patients. BGT was performed in all cases following initial failure of conventional techniques to cannulate the target circulation. BGT was successful in achieving distal cervical carotid access in 4 out of the 5 patients in whom BGT was attempted. Successful recanalization (modified treatment in cerebral ischemia 2b-3) was obtained in all cases with no complications.

CONCLUSIONS

Balloon Gliding Technique (BGT) is a safe technique that can safely overcome challenging anatomy during endovascular treatment of acute ischemic stroke. Further studies can assist in demonstrating both its safety and effectiveness.

Adapting to transradial approach in cerebral angiography: Factors influencing successful cannulation

BACKGROUND

To evaluate factors that influence the successful cannulation of intracranial vessels using a transradial approach.

METHODS

A total of 61 transradial diagnostic angiograms were evaluated in a tertiary care center from July 2020 to December 2021. We evaluated the learning curve and aortic arch vessel factors that may influence the cannulation of intracranial major vessels using a transradial approach.

RESULTS

Learning curve for the procedure was established after 21 cases. We were successful in cannulating the supra-aortic arteries except in 4 cases where we were unable to cannulate the left VA (vertebral artery). Significant positive correlation was seen between time to Sim (Simmons curve) formation and aortic arch diameter (p = .002). Significant positive correlation was also seen between left VA take-off angle and time to cannulate left VA (p = .001) and negative correlation was noted between left CCA (common carotid artery) take-off angle and time to cannulate left CCA (p = .001).

CONCLUSION

Transradial approach is a feasible and safe approach for performing cerebral angiography. Multiple factors can influence the procedure time and successful cannulation of intracranial vessels. With the availability of radial specific hardware in the future, procedural success and time taken to complete the procedure may improve.

Aortic Arch Variations and Supra-aortic Arterial Tortuosity in Stroke Patients Undergoing Thrombectomy : Retrospective Analysis of 1705 Cases

PURPOSE

Unfavorable vascular anatomy can impede thrombectomy in patients with acute ischemic stroke. The aim of this study was to determine the prevalence of aortic arch types, aortic arch branching patterns and supra-aortic arterial tortuosity in stroke patients with large vessel occlusion.

METHODS

Computed tomography (CT) and magnetic resonance (MR) images of all stroke patients in an institutional thrombectomy registry were retrospectively reviewed. Aortic arch types and branching patterns of all patients were determined. In patients with anterior circulation stroke, the prevalence of tortuosity (elongation, kinking or coiling) of the supra-aortic arteries of the affected side was additionally assessed.

RESULTS

A total of 1705 aortic arches were evaluated. Frequency of aortic arch types I, II and III were 777 (45.6%), 585 (34.3%) and 340 (19.9%), respectively. In 1232 cases (72.3%), there was a normal branching pattern of the aortic arch. The brachiocephalic trunk and the left common carotid artery had a common origin in 258 cases (15.1%). In 209 cases (12.3%), the left common carotid artery arose from the brachiocephalic trunk. Of 1598 analyzed brachiocephalic trunks and/or common carotid arteries, 844 (52.8%) had no vessel tortuosity, 592 (37.0%) had elongation, 155 (9.7%) had kinking, and 7 (0.4%) had coiling. Of 1311 analyzed internal carotid arteries, 471 (35.9%) had no vessel tortuosity, 589 (44.9%) had elongation, 150 (11.4%) had kinking, and 101 (7.7%) had coiling.

CONCLUSION

With 20%, type III aortic arches are found in a relevant proportion of stroke patients eligible for mechanical thrombectomy. Nearly half of the stroke patients present with supra-aortic arterial tortuosity, mostly arterial elongation.

A Review of the Advancements in the in-vitro Modelling of Acute Ischemic Stroke and Its Treatment

In-vitro neurovascular models of large vessel occlusions (LVOs) causing acute ischemic stroke (AIS) are used extensively for pre-clinical testing of new treatment devices. They enable physicians and engineers to examine device performance and the response of the occlusion to further advance design solutions for current unmet clinical needs. These models also enable physicians to train on basic skills, to try out new devices and new procedural approaches, and for the stroke team to practice workflows together in the comfort of a controlled environment in a non-clinical setting. Removal of the occlusive clot in its entirety is the primary goal of the endovascular treatment of LVOs via mechanical thrombectomy (MT) and the medical treatment via thrombolysis. In MT, recanalization after just one pass is associated with better clinical outcomes than procedures that take multiple passes to achieve the same level of recanalization, commonly known as first pass effect (FPE). To achieve this, physicians and engineers are continually investigating new devices and treatment approaches. To distinguish between treatment devices in the pre-clinical setting, test models must also be optimized and expanded become more nuanced and to represent challenging patient cohorts that could be improved through new technology or better techniques. The aim of this paper is to provide a perspective review of the recent advancements in the in-vitro modeling of stroke and to outline how these models need to advance further in future. This review provides an overview of the various in-vitro models used for the modeling of AIS and compares the advantages and limitations of each. In-vitro models remain an extremely useful tool in the evaluation and design of treatment devices, and great strides have been made to improve replication of physiological conditions. However, further advancement is still required to represent the expanding indications for thrombectomy and thrombolysis, and the generation of new thrombectomy devices, to ensure that smaller treatment effects are captured.

Patient and procedure selection for mechanical thrombectomy: Toward personalized medicine and the role of artificial intelligence

Mechanical thrombectomy (MT) for ischemic stroke due to large vessel occlusion is standard of care. Evidence-based guidelines on eligibility for MT have been outlined and evidence to extend the treatment benefit to more patients, particularly those at the extreme ends of a stroke clinical severity spectrum, is currently awaited. As patient selection continues to be explored, there is growing focus on procedure selection including the tools and techniques of thrombectomy and associated outcomes. Artificial intelligence (AI) has been instrumental in the area of patient selection for MT with a role in diagnosis and delivery of acute stroke care. Machine learning algorithms have been developed to detect cerebral ischemia and early infarct core, presence of large vessel occlusion, and perfusion deficit in acute ischemic stroke. Several available deep learning AI applications provide ready visualization and interpretation of cervical and cerebral arteries. Further enhancement of AI techniques to potentially include automated vessel probe tools in suspected large vessel occlusions is proposed. Value of AI may be extended to assist in procedure selection including both the tools and technique of thrombectomy. Delivering personalized medicine is the wave of the future and tailoring the MT treatment to a stroke patient is in line with this trend.

Transradial Approach for Thoracolumbar Spinal Angiography and Tumor Embolization: Feasibility and Technical Considerations

The transradial approach (TRA) is an effective and safe alternative to transfemoral access for diagnostic neuroangiography and craniocervical interventions. While the technical aspects of supraclavicular intervention are well-described, there are little data on the TRA for thoracolumbar angiography and intervention. The authors describe the feasibility of the TRA for preoperative thoracic tumor embolization, emphasizing technique, device selection, navigation, and catheterization of thoracolumbar segmental arteries. This approach extends the benefits of TRA to spinal interventional neuroradiology.

Predictors of First-Pass Effect in Endovascular Thrombectomy With Stent-Retriever Devices for Acute Large Vessel Occlusion Stroke

Background and Purpose

Successful recanalization after the first pass of the device in endovascular thrombectomy (EVT) can significantly improve patients' prognosis. We aimed to investigate the possible factors that influence achieving the first-pass effect (FPE).

Methods

We retrospectively analyzed the patients who underwent EVT caused by anterior circulation large vessel occlusion stroke (ALVOS) in our center. The FPE was defined as a successful recanalization [modified Thrombolysis in Cerebral Infarction (mTICI) 2b/3 defined as modified FPE (mFPE); mTICI 3 as true FPE (tFPE)] after one pass of the device without rescue therapy. Univariate and multivariate regression analyses were used to explore the predictors of FPE and the relationship between FPE and prognosis.

Results

There were 278 patients (age, 69.3 ± 10.9 years, male, 51.1%) included, 30.2% of them achieved mFPE, while 21.2% achieved tFPE. We found the higher clot burden score (CBS), the truncal-type occlusion, and the favorable anatomy of both extracranial and intracranial segments of the internal carotid artery (ICA) were associated with achieving mFPE. The higher CBS and truncal-type occlusion were statistically significant predictors of tFPE. Moreover, FPE was significantly associated with improved clinical outcomes, regardless of mFPE and tFPE.

Conclusions

The CBS, tortuosity of ICA, and angiographic occlusion type were independent predictors of achieving FPE. The rate of improved clinical and safety outcomes was higher in patients with FPE, which has important clinical significance.

The prognostic value of extracranial vascular characteristics on procedural duration and revascularization success in endovascularly treated acute ischemic stroke patients

Introduction

Vascular anatomy might affect endovascular treatment success in acute ischemic stroke patients with large vessel occlusion. We investigated the prognostic value of extracranial vascular characteristics on procedural time and revascularization success in patients with large vessel occlusion in the anterior cerebral circulation.

Patients and methods

We included 828 patients endovascularly treated within 6.5 hours of symptom onset from the Dutch MR CLEAN-Registry. We evaluated aortic arch configuration, stenosis and tortuosity of supra-aortic arteries, and internal carotid arteries (ICAs) on pre-intervention CTA. We constructed logistic prediction models for outcome variables procedural duration (≥60 minutes) and non-successful revascularization (extended thrombolysis in cerebral infarction (eTICI) of 0–2A) using baseline characteristics and assessed the effect of extracranial vascular characteristics on model performance.

Results

Cervical ICA tortuosity and stenosis ≥99% improved prediction of long procedural duration compared with baseline characteristics from area under the curve of 0.61 (95% CI: 0.57–0.65) to 0.66 (95% CI: 0.62–0.70) (P < 0.001). Cervical ICA tortuosity was significantly associated with non-successful recanalization. Prediction of non-successful revascularization did not improve after including aortic arch elongation, acute take-off angle, aortic variant, origin stenosis of supra-aortic arteries, and cervical ICA tortuosity, with an area under the curve of 0.63 (95% CI: 0.59–0.67) compared with 0.59 (95% CI: 0.55–0.63) (P = 0.11).

Conclusion

Extracranial vascular characteristics have additional prognostic value for procedural duration, but not for revascularization success, compared with baseline characteristics. Performance of both prediction models is limited in patients treated for large vessel occlusion.

Preprocedural Imaging : A Review of Different Radiological Factors Affecting the Outcome of Thrombectomy

BACKGROUND

Endovascular treatment (EVT) has strong evidence for its effectiveness in treatment of acute ischemic stroke (AIS); however, up to half of the patients who undergo EVT still do not have good functional outcomes. Various prethrombectomy radiological factors have been shown to be associated with good clinical outcomes and may be the key to better functional outcomes, reduced complications, and reduced mortality. In this paper, we reviewed the current literature on these imaging parameters so they can be employed to better estimate the probability of procedural success, therefore allowing for more effective preprocedural planning of EVT strategies. We reviewed articles in the literature related to imaging factors which have been shown to be associated with EVT success. The factors which are reviewed in this paper included: anatomical factors such as 1) the type of aortic arch and its characteristics, 2) the characteristics of the thrombus such as length, clot burden, permeability, location, 3) the middle cerebral artery features including the tortuosity and underlying intracranial stenosis, 4) perfusion scans estimating the volume of infarct and the penumbra and 5) the effect of collaterals on the procedure. The prognostic effect of each factor on the successful outcome of EVT is described. The identification of preprocedural thrombectomy imaging factors can help to improve the chances of recanalization, functional outcomes, and mortality. It allows the interventionist to make time-sensitive decisions in the treatment of acute ischemic stroke.

Systematic Review on Endovascular Access to Intracranial Arteries for Mechanical Thrombectomy in Acute Ischemic Stroke

PURPOSE

In acute ischemic stroke for large vessel occlusions, delayed or failed access to intracranial occlusions has a negative impact on procedural and clinical outcomes. The aim of this review is to identify and quantify access failures and challenges in mechanical thrombectomy.

METHODS

A systematic literature review of PubMed and Scopus databases from January 2014 to October 2020 was performed. Articles reporting consecutive patients were used to calculate a crude failure rate of femoral and alternative accesses.

RESULTS

A total of 50 articles met the inclusion criteria, totalling 12,838 interventions. Failure to access the occlusion through transfemoral access occurred in 4.4% of patients, most commonly due to challenging supra-aortic vessel anatomy, decreasing to 3.6% when all alternative access routes were attempted. Failed access from alternative routes (direct carotid, radial and brachial approaches) attempted first-line or after failed femoral attempt were reported in 7.3% of patients. The occurrence rate of potentially challenging features (anatomical, diseases or others) ranged from 4.7% to 47.4%, primarily impacting the access time, procedure time, recanalization and clinical outcomes.

CONCLUSION

Failure to access the occlusion is a significant contributor to failed recanalization, regardless of access routes. Challenging, but eventually successful access is also a relevant factor in procedural and clinical outcomes; however challenging access requires a universal definition to enable quantification, so that methods for procedural optimization can be critically assessed.

Comparative study of intracranial access in thrombectomy using next generation 0.088 inch guide catheter technology

BACKGROUND

Most conventional 0.088 inch guide catheters cannot safely navigate intracranial vasculature. The objective of this study is to evaluate the safety of stroke thrombectomy using a novel 0.088 inch guide catheter designed for intracranial navigation.

METHODS

This is a multicenter retrospective study, which included patients over 18 years old who underwent thrombectomy for anterior circulation large vessel occlusions. Technical outcomes for patients treated using the TracStar Large Distal Platform (TracStar LDP) or earlier generation TRX LDP were compared with a matched cohort of patients treated with other commonly used guide catheters. The primary outcome measure was device-related complications. Secondary outcome measures included guide catheter failure and time between groin puncture and clot engagement.

RESULTS

Each study arm included 45 patients. The TracStar group was non-inferior to the control group with regard to device-related complications (6.8% vs 8.9%), and the average time to clot engagement was 8.89 min shorter (14.29 vs 23.18 min; p=0.0017). There were no statistically significant differences with regard to other technical outcomes, including time to recanalization (modified Thrombolysis In Cerebral Infarction (mTICI) ≥2B). The TracStar was successfully advanced into the intracranial internal carotid artery in 33 cases (73.33%); in three cases (6.67%), it was swapped for an alternate catheter. Successful reperfusion (mTICI 2B-3) was achieved in 95.56% of cases. Ninety-day follow-up data were available for 86.67% of patients, among whom 46.15% had an modified Rankin Score of 0-2%, and 10.26% were deceased.

CONCLUSIONS

Tracstar LDP is safe for use during stroke thrombectomy and was associated with decreased time to clot engagement. Intracranial access was regularly achieved.

#RadialFirst and #RadialForNeuro: A descriptive analysis of Twitter conversations regarding transradial access

BACKGROUND

Transradial access for neurointerventional procedures was adopted and modified from cardiovascular intervention and is increasingly established as a safe and effective alternative to transfemoral catheterization. As social media influences public opinion on medical treatment, this study analyzes Twitter conversations to elucidate social media's depiction of transradial access as a neurointerventional tool.

MATERIALS AND METHODS

Twitter hashtags #RadialFirst and #RadialForNeuro were evaluated using a mixed-method analysis of quantitative social media metrics and qualitative thematic analysis.

RESULTS

Between January 2015 and April 2020, 104,146 tweets from 141 countries employed the hashtag #RadialFirst (2015 (1); 2016 (0); 2017 (22,804); 2018 (33,074); 2019 (38,352); 2020 (9,915 January-April)). These generated 226,909,374 impressions and were retweeted 80,120 times by 13,707 users. Media was present in 62.5% of tweets (e.g. wrist image, angiographic runs) but only 14.5% had a reference article. Physicians authored 70.8% of tweets; interventional cardiologists accounted for 83% of top 100 influencers. #RadialForNeuro is more nascent (6 posts in 2019; 323 posts January-April 2020), with 392,662 impressions, and 254 retweets by 177 users; physicians authored 35.6%. Compared to #RadialFirst, #RadialforNeuro tweets were more likely to include media (76%), less likely to include citations (9.7%), and more likely to discuss complications and troubleshooting techniques.

CONCLUSION

Twitter activity regarding transradial access permits information dissemination and discussion on approach benefits and challenges. However, many posts arise from non-physician sources and lack links to peer-reviewed publication. The public should be mindful that tweets may reflect opinions, rather than experience or scientific evidence.

Tortuosity Index Predicts Early Successful Reperfusion and Affects Functional Status After Thrombectomy for Stroke

OBJECTIVE

The literature is scarce for studies evaluating the anatomy of cervical vessels in patients with stroke. We sought to investigate the effect of vessel tortuosity in procedural, angiographic, and functional outcomes in patients with acute ischemic stroke treated with mechanical thrombectomy (MT).

METHODS

Patients with an emergent large vessel occlusion of the anterior circulation treated with MT between 2015 and 2020 were included. The tortuosity of the internal carotid artery was recorded as the tortuosity index (TI) using the following formula: [(actual/straight length-1) × 100). A multivariable regression was performed to assess procedural, angiographic, and functional outcomes based on the TI.

RESULTS

A total of 212 patients were included. Median age was 72 years (interquartile range, 62-82 years); admission National Institutes of Health Stroke Scale score was 17 ± 6. Median TI was 7.9 (interquartile range, 3.7-19.7). A total of 127 patients (60%) had a TI <10. Early reperfusion (procedure time <60 minutes) was accomplished in 144 patients (67.9%). A multivariable analysis showed that patients with a TI <10 were more likely to achieve an early reperfusion (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.11-4.78; P = 0.025). A TI <10 was a predictor of successful reperfusion (OR, 2.0; CI, 1.05-3.93; P = 0.035) and an early reperfusion was the sole predictor of functional independence (most recent modified Rankin Scale score 0-2) (OR, 4.1; 95% CI, 1.62-10.53; adjusted P = 0.003).

CONCLUSIONS

Patients with a TI <10 are significantly more likely to achieve early successful reperfusion after MT for the treatment of acute ischemic stroke.

Thoraco-Cervical Computed Tomographic Angiography to Determine an Appropriate Access Route for Mechanical Thrombectomy

Objective

We investigated whether thoraco-cervical CTA provided useful information to determine an access route (AR) for mechanical thrombectomy (MT).

Methods

We included acute stroke patients who (1) were admitted between January 2018 and December 2018 and (2) underwent MT for large artery occlusion in the anterior circulation and were able to be treated within 24 hours of the time last known to be well. We evaluated the AR, occlusion site, aortic arch (AA) type, take-off angles (TOA) between the arch and the left common carotid artery (CCA) or the brachiocephalic artery (BCA), successful insertion rate (SIR) of the guiding catheter, puncture-to-initial angiography time (PtIA), and puncture-to-reperfusion time (PtR).

Results

We analyzed 32 patients: femoral-artery access (group F) in 26 and brachial-artery access (group B) in 6 patients. There were no differences in arch types between the two groups, but there were differences in occlusion sites: proximal CCA occlusion in two patients in the B group. Moreover, the TOA of the CCA was less than 25° in two patients in the B group. In the F and B groups, the SIR was 100%, the median PtIA was 9.0 and 9.6 minutes, and the median PtR was 54 and 72 minutes, respectively.

Conclusion

Thoraco-cervical CTA provided useful information to determine the appropriate AR for MT. SIR of 100% and short PtIA were achieved.

Efficacy of Asahi Fubuki as a Guiding Catheter for Mechanical Thrombectomy: An Institutional Case Series

Treatment outcomes of mechanical thrombectomy for acute stroke secondary to large-vessel occlusion in which the Asahi Fubuki was used as a guide catheter were reviewed. Among 154 patients treated with mechanical thrombectomy, the Fubuki was successfully delivered to the cervical ICA in 151 cases (98.1%) and the lesion was successfully crossed in 150 cases (97.4%). Median times to lesion crossing and revascularization were 9 and 19 minutes, respectively.