Experienced Neurointerventionalists Research Articles

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

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. 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 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. 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.

Modeling Robotic-Assisted Mechanical Thrombectomy Procedures with the CorPath GRX Robot: The Core-Flow Study.

Endovascular robotic devices may enable experienced neurointerventionalists to remotely perform endovascular thrombectomy. This study aimed to assess the feasibility, safety, and efficacy of robot-assisted endovascular thrombectomy compared with manual procedures by operators with varying levels of experience, using a 3D printed neurovascular model. M1 MCA occlusions were simulated in a 3D printed neurovascular model, linked to a CorPath GRX robot in a biplane angiography suite. Four interventionalists performed manual endovascular thrombectomy (n = 45) and robot-assisted endovascular thrombectomy (n = 37) procedures. The outcomes included first-pass recanalization (TICI 2c-3), the number and size of generated distal emboli, and procedural length. A total of 82 experimental endovascular thrombectomies were conducted. A nonsignificant trend favoring the robot-assisted endovascular thrombectomy was observed in terms of final recanalization (89.2% versus manual endovascular thrombectomy, 71.1%; P = .083). There were no differences in total mean emboli count (16.54 [SD, 15.15] versus 15.16 [SD, 16.43]; P = .303). However, a higher mean count of emboli of > 1 mm was observed in the robot-assisted endovascular thrombectomy group (1.08 [SD, 1.00] versus 0.49 [SD, 0.84]; P = .001) compared with manual endovascular thrombectomy. The mean procedural length was longer in robot-assisted endovascular thrombectomy (6.43 [SD, 1.71] minutes versus 3.98 [SD, 1.84] minutes; P < .001). Among established neurointerventionalists, previous experience with robotic procedures did not influence recanalization (95.8% were considered experienced; 76.9% were considered novices; P = .225). In a 3D printed neurovascular model, robot-assisted endovascular thrombectomy has the potential to achieve recanalization rates comparable with those of manual endovascular thrombectomy within competitive procedural times. Optimization of the procedural setup is still required before implementation in clinical practice.

Fly and treat: Endovascular treatment of ruptured aneurysms at an insular tertiary center

(Objectives) Aneurysmal subarachnoid hemorrhage (aSAH) is a life-threatening condition associated with poor outcomes. Early intervention is critical, particularly in low-volume hospitals, which are advised to transfer aSAH patients to high-volume centers. This study examines a novel protocol implemented in 2016 at Região Autónoma da Madeira, a Portuguese island. It involves the mobilization of experienced neurointerventionalists from high-volume hospitals to provide aSAH treatment. (Methods) We conducted a retrospective analysis on 30 aSAH patients who underwent endovascular treatment at the island center between November 2016 and April 2022. Additionally, we included a comparison group of 74 aSAH patients, treated with the endovascular approach at Hospital de Braga (high volume center at Portugal mainland). (Results) There was no statistical difference in patients' clinical severity between both hospitals (median WFNS score of 1). Although 90 % of patients in the novel protocol group received treatment within 3 days, we observed a significant delay compared to Hospital de Braga. Rates of aneurysm occlusion and intra-procedure complications between the two groups were similar. At the 3-months follow-up, there were no statistically significant differences between groups regarding patients that achieved a modified Rankin score of 2 or less. However, the island center exhibited a significantly higher mortality rate. (Conclusions) Overall, our results suggest that making the neurointerventionalist fly to an insular center is feasible and allows most patients to be treated within the first 72 h, as recommended. We highlight some potential recommendations for implementing this model and discuss possible causes that might justify the high mortality rate.

Development of an in-vitro model based on patient vessel geometry for simulated use testing in neurointerventional surgery.

Neurointerventionalists use in-vitro vascular models to train for worst-case scenarios and test new devices in a simulated use environment to predict clinical performance. According to the Food and Drug Administration (FDA), any neurovascular navigation device should be able to successfully navigate two 360-degree turns and two 180-degree turns at the distal portion of the anatomical model. Here, we present a device benchmarking vascular model that complies with FDA recommendations. Our vascular model was assembled from quantitative characterization of 49 patients who underwent CT angiography either for acute ischemic stroke caused by large vessel occlusion or for aneurysm treatment. Following complete characterization of these data, the vascular segments were 3D reconstructed from CT angiograms of 6 selected patients that presented with challenging anatomy. The curvature and total rotational angle were calculated for each segment and the anatomical parts that complied with FDA recommendations were fused together into a single in-vitro model. The model was constructed containing two common carotid branches arising from a type two aortic arch and the dimensions of the overall model exceeded the recommendations of the FDA. Two experienced neurointerventionalists tested the model for navigation difficulty using several devices on an in-vitro perfusion system and concluded that the model provided a realistic, challenging scenario. This model provides a first prototype designed according to FDA recommendations of cumulative angle while also integrating an aggregation of actual patient-specific anatomy. The availability of this clinically relevant benchmark model presents a potential standardized approach for neurovascular device testing.

Procedural and Clinical Outcome Analysis of Monoplane versus Biplane Angiography Suites in Stroke Thrombectomies

Thrombectomy is now the standard of care in the treatment of acute ischemic stroke caused by emergent large vessel occlusion. Therefore, thrombectomy services have expanded from Comprehensive Stroke Centers (CSCs) to Thrombectomy-Capable Stroke Centers (TSCs). Stroke interventions at these sites are performed in both biplane and monoplane angiography suites. It has been hypothesized that differences in these systems may affect time to successful reperfusion, with a potentially significant effect on neurological outcomes. With an increase in TSCs, this study aims to evaluate the safety and efficacy of monoplane thrombectomy versus biplane thrombectomy. Patients who presented with isolated proximal middle cerebral artery (MCA) M1 occlusions and underwent endovascular thrombectomy from March 2015 to August 2018 at five different centers within a single health system were included. Thrombectomy was performed by the same group of experienced neurointerventionalists. The primary endpoint was functional outcome as measured by the modified Rankin scale at 90 days. Secondary endpoints included recanalization grade as measured by the Thrombolysis in Cerebral Infarction (TICI) score, time to final reperfusion and incidence of hemorrhagic conversion. A total of 197 patients were included in this study. Of them, 80.7% underwent thrombectomy on biplane systems. Time to final reperfusion was 10.2 minutes longer in the monoplane group but was not statistically significant (p=0.252). There was no significant difference in the rates of favorable reperfusion (p=0.755), hemorrhagic conversion (p=0.580), or functional outcome at 90 days (Favorable mRS 0-2, p=0.210; favorable mRS 0-3, p=0.697). Despite perceived advantages of biplane systems in reducing procedural time, our study demonstrates no significant differences between systems. This data not only supports the safety and efficacy of performing thrombectomy on monoplane systems, but also may carry implications for reducing patient transfer times and potentially increasing thrombectomy access to areas of the world where biplane suites may not be available. The next step would be a prospective randomized trial comparing both systems in different settings.

Feasibility, Safety, and Technical Success of the Flying Intervention Team in Acute Ischemic Stroke

BackgroundPrompt endovascular care of patients with ischemic stroke due to large vessel occlusion (LVO) remains a major challenge in rural regions as primary stroke centers (PSC) usually cannot provide neuro-interventional services. Objective The core content of the Flying Intervention Team (FIT) project is to perform thrombectomy on-site at a local PSC after the neuro-interventionalist has been transported via helicopter to the target hospital. An important and so far unanswered question is whether mechanical thrombectomy can be performed as safely and successfully on-site as in a specialized comprehensive stroke center (CSC).MethodsComparison of 100 FIT thrombectomies on site in 14 different PSCs with 128 control thrombectomies at 1 CSC (79 drip-and-ship, 49 mothership) performed by a single interventionalist with respect to technical-procedural success parameters, procedural times, and complications.ResultsThere were no significant differences between the two groups in terms of technical success (95.0% successful interventions in FIT group vs. 94.5% in control group, p = 0.60) and complications (3% major complications in FIT vs. 1.6% in control group, p = 0.47). Regarding time from onset to groin puncture, there was no difference between FIT and the entire control group (182 vs. 183 min, p = 0.28), but a trend in favor of FIT compared with the drip-and-ship control subgroup (182 vs. 210 min, p = 0.096).ConclusionsAirborne neuro-interventional thrombectomy service is a feasible approach for rural regions. If performed by experienced neuro-interventionalists, technical success and complication rates are comparable to treatment in a specialized neuro-interventional department.

Machine learning to predict in-stent stenosis after Pipeline embolization device placement.

BackgroundThe Pipeline embolization device (PED) is a flow diverter used to treat intracranial aneurysms. In-stent stenosis (ISS) is a common complication of PED placement that can affect long-term outcome. This study aimed to establish a feasible, effective, and reliable model to predict ISS using machine learning methodology.MethodsWe retrospectively examined clinical, laboratory, and imaging data obtained from 435 patients with intracranial aneurysms who underwent PED placement in our center. Aneurysm morphological measurements were manually measured on pre- and posttreatment imaging studies by three experienced neurointerventionalists. ISS was defined as stenosis rate >50% within the PED. We compared the performance of five machine learning algorithms (elastic net (ENT), support vector machine, Xgboost, Gaussian Naïve Bayes, and random forest) in predicting ISS. Shapley additive explanation was applied to provide an explanation for the predictions.ResultsA total of 69 ISS cases (15.2%) were identified. Six predictors of ISS (age, obesity, balloon angioplasty, internal carotid artery location, neck ratio, and coefficient of variation of red cell volume distribution width) were identified. The ENT model had the best predictive performance with a mean area under the receiver operating characteristic curve of 0.709 (95% confidence interval [CI], 0.697–0.721), mean sensitivity of 77.9% (95% CI, 75.1–80.6%), and mean specificity of 63.4% (95% CI, 60.8–65.9%) in Monte Carlo cross-validation. Shapley additive explanation analysis showed that internal carotid artery location was the most important predictor of ISS.ConclusionOur machine learning model can predict ISS after PED placement for treatment of intracranial aneurysms and has the potential to improve patient outcomes.

Remote Training of Neurointerventions by Audiovisual Streaming

BackgroundRemote access of trainees to training centers via video streaming (tele-observership, e‑fellowship) emerges as an alternative to acquire knowledge in endovascular interventions. Situational awareness is a summary term that is also used in surgical procedures for perceiving and understanding the situation and projecting what will happen next. A high situational awareness would serve as prerequisite for meaningful learning success during tele-observerships. We hypothesized that live perception of the angiographical procedures using streaming technology is feasible and sufficient to gain useful situational awareness of the procedure.MethodsDuring a European tele-observership organized by the European Society of Minimally Invasive Neurological Therapy (ESMINT) and its trainee association (EYMINT), a total of six neurointerventional fellows in five countries observed live cases performed by experienced neurointerventionalists (mentors) in six different high-volume neurovascular centers across Europe equipped with live-streaming technology (Tegus Medical, Hamburg, Germany). Cases were prospectively evaluated during a 12-month period, followed by a final questionnaire after completion of the course.ResultsA total of 102/161 (63%) cases with a 1:1 allocation of fellow and mentor were evaluated during a 12-month period. Most frequent conditions were ischemic stroke (27.5%), followed by embolization of unruptured aneurysms (25.5%) and arteriovenous malformations (AVMs) (15.7%). A high level of situational awareness was reported by fellows in 75.5% of all cases. After finishing the program, the general improvement of neurointerventional knowledge was evaluated to be extensive (1/6 fellows), substantial (3/6), and moderate (2/6). The specific fields of improvement were procedural knowledge (6/6 fellows), technical knowledge (3/6) and complication management (2/6).ConclusionOnline streaming technology facilitates location-independent training of complex neurointerventional procedures through high levels of situational awareness and can therefore supplement live hands-on-training. In addition, it leads to a training effect for fellows with a perceived improvement of their neurointerventional knowledge.

Training Guidelines for Endovascular Ischemic Stroke Intervention: An International multi-society consensus document

Ischemic stroke is a leading cause of death and disability worldwide. Much of the long-term disability occurs in patients with Emergent Large Vessel Occlusion (ELVO). In fact, in these patients,...

Rapid learning curve for Solitaire FR stent retriever therapy: evidence from roll-in and randomised patients in the SWIFT trial

BackgroundIn light of recent positive trial data for endovascular therapy in acute ischemic stroke (AIS), stent retriever use by practitioners without prior experience with these devices may become more common.ObjectiveTo...

An Evidence-based Update on Acute Endovascular Stroke Therapy

In 2015, there is now level 1 evidence from prospective randomized controlled trials proving the clinical efficacy of acute endovascular stroke therapy. Specifically, patients who would stand to benefit need to have a large vessel occlusion (LVO), need to be treated within the first 6 hours after symptom onset, and be treated by experienced neurointerventionalists who can consistently achieve high rates of Thombolysis in Cerebral Infarction (TICI) 2b/3 recanalization.

E-064 ASPECTS ≥5 on Non-Contrast CT and CT Angiography Source Images Predicts Clinical Outcome in a Cohort of 30 Patients Undergoing Mechanical Thrombectomy with Stent-Retrievers

PurposeTo determine if the Alberta Stroke Program Early CT Score (ASPECTS) applied to non-contrast CT (NCCT) and CT angiography source images (CTA-SI) predicts clinical outcome in a cohort of patients...

Feasibility and Utility of Transradial Cerebral Angiograpy: Experience during the Learning Period

ObjectiveWe wanted to present our experiences for performing transradial cerebral angiography during the learning period, and we also wanted to demonstrate this procedure's technical feasibility and utility in various clinical situations.Materials and MethodsThirty-two patients were enrolled in the study. All of them had unfavorable situations for performing transfemoral angiography, i.e., IV lines in the bilateral femoral vein, a phobia for groin puncture, decreased blood platelet counts, large hematoma or bruise, atherosclerosis in the bilateral femoral artery and the insistence of patients for choosing another procedure. After confirming the patency of the ulnar artery with a modified Allen's test and a pulse oximeter, the procedure was done using a 21-G micorpuncture set and 5-F Simon II catheters. After angiography, hemostasis was achieved with 1-2 minutes of manual compression and the subsequent application of a hospital-made wrist brace for two hours. The technical feasiblity and procedure-related immediate and delayed complications were evaluated.ResultsThe procedure was successful in 30/32 patients (93.8%). Failure occurred in two patients; one patient had hypoplasia of the radial artery and one patient had vasospasm following multiple puncture trials for the radial artery. Transradial cerebral angiography was technically feasible without significant difficulties even though it was tried during the learning period. Pain in the forearm or arm developed in some patients during the procedures, but this was usually mild and transient. Procedure-related immediate complications included severe bruising in one patient and a small hematoma in one patient. Any clinically significant complication or delayed complication such as radial artery occlusion was not demonstrated in our series.ConclusionTransradial cerebral angiography is a useful alternative for the patients who have unfavorable clinical situations or contraindications for performing transfemoral cerebral angiography. For the experienced neurointerventionalists, it seems that additional training for perfoming transradial cerebral angiography is not needed.