Neuroendovascular Therapy Research Articles

Temporal Trends in Endovascular Therapy for Acute Stroke in the Era of Modern Mechanical Thrombectomy: the JR-NET4 Study.

This study aimed to examine nationwide trends in acute stroke endovascular thrombectomy (EVT) following five pivotal trials in 2015 that established it as the 'standard of care'. The Japanese Registry of NeuroEndovascular Therapy 4 was a nationwide retrospective study registering consecutive patients who underwent neurointervention by specialists certified by the Japanese Society for Neuroendovascular Therapy at 166 centers from January 2015 to December 2019. We extracted patients who underwent EVT, and analyzed the annual trends in baseline characteristics, revascularization procedures and outcomes. A total of 13,090 patients (75.3±12.2 years, 5637 women) were included. Analyses revealed an annual increase in patient age and treatments beyond 6 hours after onset. However, there was an annual decline in premorbidly independent patients and those with large vessel occlusion. The frequency of stent-aspiration techniques and rate of successful reperfusions significantly increased from 19.9% to 51.0% and from 81.4% to 83.9%, respectively through the study period. Trends in patients achieving a favorable (modified Rankin Scale score of 0-2 at 30 days) or fatal outcome, or experiencing intracranial hemorrhagic complications remained unchanged. However, calendar time was associated with favorable outcomes after adjusting for clinical and treatment characteristics (odds ratio, 1.040; P = 0.015). During the study period, EVT indications expanded for patients with characteristics linked to worse outcomes. However, factors such as advancements in techniques, have led to modest but significant improvements in reperfusion status, leading to maintenance of the post-EVT clinical outcomes. URL: https://www.umin.ac.jp/ctr/; Unique identifier: UMIN000038869.

Impact of Intracranial Hemorrhage After Endovascular Treatment for Medium Vessel Occlusion.

Endovascular treatment (EVT) for medium vessel occlusion (MeVO) raises concern about hemorrhagic complications; however, its clinical impact has not been elucidated. Therefore, we investigated the association between intracranial hemorrhage (ICH) after EVT for MeVO and functional outcomes. We conducted a post hoc analysis of the Japan Registry of NeuroEndovascular Therapy 4, a nationwide registry in Japan from 2015 to 2019 including 13 479 patients who underwent EVT for acute ischemic stroke. This study included 2465 patients with MeVO from 166 participating centers in Japan. We compared patients who underwent EVT for MeVO according to their hemorrhagic complication after EVT (no ICH, asymptomatic ICH, and symptomatic ICH). Outcomes included a modified Rankin scale (mRS) score at 30 days and all-cause mortality within 30 days. We estimated the odds ratios (ORs) and their CIs using a multivariable logistic regression model. Among 2394 patients analyzed, 302 (12.6%) developed ICH, with 95 (31.5%) being symptomatic. Compared with the no-ICH group (n = 2092), the asymptomatic and symptomatic ICH groups had a lower proportion of patients with an mRS score of 0 to 2 at 30 days (41% vs 34%, vs 7.4%, P for trend <.001), with an adjusted ORs of 0.77 (95% CI, 0.53-1.12) and 0.12 (95% CI, 0.05-0.30) in the asymptomatic and symptomatic ICH groups, respectively. The adjusted common ORs of one-point shift of mRS score at 30 days in the asymptomatic ICH group was 0.76 (95% CI, 0.57-0.99) and that of the symptomatic ICH group was 0.13 (0.07-0.23), compared with the no-ICH group. ICH after EVT for MeVO was associated with worse outcomes, whether they were symptomatic or not. The optimal treatment devices or techniques to reduce ICH after EVT for MeVO are crucial.

Early neurological changes following endovascular therapy for acute stroke due to intracranial atherosclerotic disease

BackgroundEndovascular therapy (EVT) reduces functional disability in patients with acute large vessel occlusion (LVO). However, the early neurological change after EVT may be limited in patients with intracranial atherosclerotic disease (ICAD). MethodsWe analyzed the Japanese Registry of NeuroEndovascular Therapy (JR-NET) 4 which was a retrospective, nationwide, multicenter registry of patients with LVO between 2015 and 2019. We compared the early neurological change, efficacy and safety of EVT for acute LVO in ICAD and other etiologies. The primary outcome was NIHSS improvement ≥10 points, and secondary outcome were NIHSS worsening ≥4 points 7 days after EVT, effective reperfusion rate, 30-day functional outcomes, and safety outcomes. ResultsAmong the 6710 enrolled patients, 610 (9.1%) had ICAD. The ICAD group was younger (mean 72.0 vs. 75.8 years) and predominantly male (63.4% vs. 56.0%), had lower NIHSS scores before EVT (median 16 vs. 18), and underwent percutaneous transluminal angioplasty and stenting more frequently (43.0% vs. 4.4%, 12.3% vs. 4.4%). In the ICAD group, NIHSS improvement was significantly lower (adjusted odds ratio (aOR) [95% confidence interval (95%CI)] 0.52 [0.41–0.65]), NIHSS worsening was significantly higher (aOR [95%CI] 1.76 [1.31–2.34]), and effective reperfusion was significantly lower (aOR [95%CI] 0.47 [0.36–0.60]). Fewer patients with ICAD had modified Rankin scale 0–2 at 30 days (aOR [95%CI] 0.60 [0.47–0.77]). The risk of acute reocclusion was more prominent in the ICAD group (aOR [95%CI] 4.03 [1.98–8.21]). ConclusionsImprovement in neurological severity after EVT was lower in patients with LVO and ICAD.

Comparison of outcomes with/without preoperative embolization for meningiomas with diluted N-butyl-2-cyanoacrylate

BackgroundPreoperative embolization for meningiomas is controversial regarding its effectiveness in reducing intraoperative blood loss and operative time. In contrast, some reports have documented improved surgical outcomes in large meningiomas. In this study, we retrospectively compared the outcomes of craniotomy for meningiomas with/without preoperative embolization with diluted N-butyl-2-cyanoacrylate (NBCA) primarily in a single institution. MethodsData (World Health Organization grade, Simpson grade, maximum tumor diameter, intraoperative bleeding, operative time, history of hypertension, and time from embolization to craniotomy) of patients with initial intracranial meningiomas were compared with or without preoperative embolization from January 2015 to April 2022. ResultsThe embolization group consisted of 56 patients and the nonembolization group included 76 patients. Diluted NBCA (13% concentration for all patients) was used in 51 of 56 patients (91.1%) who underwent transarterial embolization. Permanent neurological complications occurred in 2 (3.6%) patients. Intraoperative bleeding was significantly lower in the embolization group for a maximum tumor diameter ≥40 mm (155 vs. 305 ml, respectively, p < 0.01). In the nonembolization group, for a maximum tumor diameter ≥30 mm, patients with hypertension had more intraoperative bleeding than non-hypertensive ones. ConclusionsDespite its limitations, the present results showed that, under certain conditions, preoperative embolization for intracranial meningiomas caused less intraoperative bleeding. The safety of treatment was comparable with that reported in the Japan Registry of NeuroEndovascular Therapy 3 (JR-NET3) with a complication rate of 3.7% for preoperative embolization of meningiomas, despite the treatment focused on the liquid embolization material.

Feasibility and Challenges of Transradial Approach in Neuroendovascular Therapy: A Retrospective Observational Study.

Transradial approach (TRA) is increasingly used as a viable alternative to the traditional transfemoral approach (TFA) in neuroendovascular therapy (NET) owing to its potential anatomical benefits and lower puncture-site complication rates. However, the real-world challenges of implementing TRA-NET have not been thoroughly studied, particularly those related to guide catheter (GC) placement. In this study, we aimed to explore the feasibility and challenges of TRA-NET, with a specific focus on GC placement. This retrospective observational study included patients who underwent NET at our institution between December 2019 and May 2022. Procedural success was defined as the successful placement of a GC in the target vessel. Cases in which a Simmons-shaped GC was used or the approach was changed to TFA were classified as difficult. Safety was assessed based on the rate of severe puncture-site complications requiring either blood transfusion or surgical intervention. Among the 310 patients who underwent NET during the study period, 222 (71.6%) with a median age of 74 years were selected for TRA-NET. The target vessel was in the left anterior circulation (LtAC) in 101 (45.5%) patients, and 8-F GCs were the most frequently used (40.1%). TRA-NET achieved a 95.0% success rate, with a switch to TFA required in 5.0% of the cases. Procedural challenges occurred in 42 (18.9%) patients, primarily in those with LtAC lesions. Specifically, a type III aortic arch (p <0.0001) and age ≥80 years (p = 0.01) were significantly associated with procedural difficulties. Radial artery evaluation was confirmed in 66 cases (29.7%), revealing one instance (1.5%) of radial artery occlusion. No severe puncture-site complications were observed. TRA-NET may provide substantial therapeutic benefits without significant limitations in device use. However, it may be challenging, particularly in older patients and those with a type III aortic arch with LtAC lesions. Consequently, careful selection of the approach route is imperative.

Efforts toward Gender Equality and Diversity in the Japanese Society for Neuroendovascular Therapy.

The Japanese Society for Neuroendovascular Therapy (JSNET) is a diverse subspecialty society based on four basic fields and is continuously growing with the advancement of neuroendovascular therapy. Despite a recent increase in the proportion of female members, awareness of diversity within JSNET remains inadequate. To foster a more mature and inclusive society, we established the JSNET-Diversity Promotion Committee in 2021, which has actively engaged in various initiatives aimed at promoting the inclusion of minorities such as female physicians as well as minority fields. Our objective is to continue in our initiative, anticipating that JSNET will evolve into an even more ideal organization in the future.

Real-world Data of Antithrombotic Therapy in Neuroendovascular Therapy: Analysis of JR-NET 4.

As the number of neuroendovascular therapies in Japan increases, the current trends in periprocedural antithrombotic therapy must be understood.We retrospectively analyzed data on periprocedural antithrombotic therapy in the Japanese Registry of Neuroendovascular Therapy (JR-NET) 4, a nationwide survey carried out in Japan between January 2015 and December 2019. Details on antithrombotic therapy in neuroendovascular therapy for ruptured cerebral aneurysms, unruptured cerebral aneurysms, and percutaneous transluminal angioplasty or stenting were collected from the JR-NET 4 database. These data were analyzed and compared with those from the JR-NET 2 (January 2008 to December 2009) and JR-NET 3 (January 2010 to December 2014). A total of 36,560 cases were analyzed in the JR-NET 4. The frequency of preprocedural dual antiplatelet therapy (DAPT) significantly increased from the JR-NET 2 to 4 (48.1%, 53.4%, and 62.3%, respectively; P < 0.001), whereas the frequency of monotherapy significantly decreased (15.7%, 13.9%, and 8%, respectively; P < 0.001). Postprocedural antiplatelet therapy exhibited similar trends, and postprocedural anticoagulant therapy was discontinued. Particularly, heparin use significantly decreased from the JR-NET 2 to 4 (23.4% vs. 12.7% vs. 7.9%, respectively; P < 0.001). In terms of periprocedural complications, the incidence of ischemic complications increased from the JR-NET 3 to 4 (5.8% vs. 6.2%; P = 0.05). In the JR-NET 4, severe adverse events and hemorrhagic and all complications were significantly more frequent in the preprocedural triple or more therapy group.The rate of postprocedural anticoagulant therapy decreased, whereas that of antiplatelet therapy increased. Overall, in Japan, periprocedural DAPT has become increasingly common.

Making Neuroendovascular Therapy for Cerebrovascular Disease Using Distal/Trans-radial Artery Access Safer.

Neuroendovascular therapy using distal/trans-radial artery access (d/TRA) has attracted attention as a less invasive procedure. We have selected dTRA or TRA in all cases of carotid artery stenting (CAS). In recent years, TRA has been actively selected for mechanical thrombectomy for acute ischaemic stroke (MT for AIS) and Onyx embolisation for arteriovenous malformations. We compared the patient background, surgical strategy, perioperative complications, and outcome in 41 patients who underwent CAS in the first period (Apr 2017-Feb 2019) and 12 patients in the second period (Apr 2020-Feb 2022) avoiding trans-femoral artery access (TFA) as possible. We compared the patient background, surgical strategy, perioperative complications, and outcome in 46 patients who underwent MT for AIS via TFA from Apr 2022 to Dec 2022 as the first period and five patients who underwent MT for AIS via TRA from Jan 2023 to Sep 2023 as the second period. Concerning CAS, the second period included significantly more symptomatic cases, with a higher rate of edaravone use to prevent hyperperfusion and a significantly smaller sheath diameter. In the second period, CAS was performed in severe conditions; nevertheless, there was no significant difference between the two groups in terms of either the ratio of cases detected by postoperative diffusion-weighted imaging positive or the ratio of cases with puncture site-related complications (PSCs). Concerning MT for AIS, there were no significant differences between the two groups with the patient backgrounds. The percentage of effective reperfusion, time from puncture to recanalisation, and outcome in the second period were all non-inferior to those in the first period when conventional MT for AIS was performed. Even though we introduced d/TRA in patients with cognitive decline and inability to remain at rest during the perioperative period, we completely avoided PSCs via d/TRA. In particular, cerebral hyperperfusion syndrome after CAS and ischaemia-reperfusion injury or re-occlusion after MT were rare but critical perioperative complications, and near-infrared spectroscopy (NIRS) may be used to monitor these problems. We introduced intensive evaluation by NIRS if we had time to spare.

Trends and Progress in Neuroendovascular Treatment in Japan: Japanese Registry of Neuroendovascular Therapy (JR-NET) 4. Main Report.

We reported the main results of the Japanese Registry of Neuroendovascular Therapy (JR-NET) 4, a nationwide surveillance of therapy (NET) in Japan from January 2015 to December 2019. JR-NET 4 registered consecutive patients who underwent NETs by Japan Society of Neuroendovascular Therapy (JSNET) -certified specialists. The primary endpoint was functional independence (mRS score of 0-2) at 30 days post-NET, with secondary endpoints focusing on technical success and major adverse events within 30 days.A total of 63,230 patients and 60,354 NET procedures from 166 participating centers were analyzed. During the study period, NET cases have consistently increased, with an increase in the proportion of elderly patients. A significant trend shift was observed in the distribution of NET procedures, with endovascular treatment for acute ischemic stroke that showed a dramatic increase in 5 years. This trend aligns with key randomized clinical trials from 2015 that presented the efficacy of this treatment. Clinical outcomes at 30 days posttreatment revealed that endovascular treatment for acute ischemic stroke and other NETs maintained safety and effectiveness despite varying prevalence of functional independence between target diseases. The study also observed a steady increase in emergency treatment cases, reflecting the increase in acute ischemic stroke, a time-sensitive medical condition.This comprehensive surveillance highlights the trend of NET practices in Japan, driven by clinical evidence and advancements in treatment devices. Although these findings were specific to Japan, they offer valuable insights into the broader trends in NETs and acute stroke care.

The Current Status of Endovascular Treatment for Extracranial Vertebral Artery Stenosis in Japan: A Subanalysis of the Japanese Registry of Neuroendovascular Therapy 4.

Endovascular treatment (EVT) is a potential therapeutic option for extracranial vertebral artery (VA) stenosis; however, its efficacy or optimal procedures remain unknown. This study aimed to investigate the recent status of EVT for extracranial VA stenosis in Japan using a nationwide registry. We conducted a post hoc analysis of the Japanese Registry of Neuroendovascular Therapy 4 that enrolled patients who underwent EVT at 166 hospitals in Japan from 2015 to 2019. The outcomes of this study were as follows: procedural success indicating that the planned procedure was completed, modified Rankin Scale (mRS) score at 30 days, and procedure-related complications evaluated according to the procedure during EVT (percutaneous transluminal angioplasty vs. stenting and with or without the use of embolic protection devices [EPDs]). Of 308 eligible patients, 301 (95%) were treated for atherosclerotic stenosis, predominantly by stenting (74%). EPDs were used in 43%, primarily with the distal balloon (63%). The proportion of procedural success was 98%. Functional independence (mRS of 0-2) at 30 days was achieved in 80% of the total cohort, and there were no differences between patients treated with or without stenting or EPDs (74% vs. 82%, p = 0.12, and 80% vs. 80%, p = 0.93). Procedural complications occurred in 28 (9.1%) patients similarly in each group, with distal embolism and vessel dissection being common. In conclusion, EVT is a reasonable option for extracranial VA stenosis as a daily clinical practice. This study emphasizes the potential of EVT in managing extracranial VA stenosis and the need for further research to refine treatment strategies.

Detail analysis of puncture site complications in neuro-endovascular therapy: A single-center analysis

ObjectivePuncture site complications in neuro-endovascular therapy, which represent a significant cause of morbidity, are often difficult to treat. Vascular closure devices have evolved in endovascular therapy. We analyzed risk factors for puncture site complications and examined the efficacy of hemostasis methods in neuro-endovascular therapy. MethodsThis retrospective, observational, single-center study was conducted from January 2021 to January 2023. We enrolled 202 puncture sites of patients who underwent neuro-endovascular therapy at Kawaguchi Municipal Medical Center and analyzed the complications requiring additional intervention. ResultsThere were 12 (5.94 %) puncture site complications. No patient had permanent puncture-related complications. Univariate analyses revealed that a higher risk of puncture site complications was significantly associated with multiple antiplatelet agents (p = 0.03), hypertension (p = 0.03), scheduled treatment (p < 0.01), higher activated clotting time (ACT) immediately before sheath removal (≥310 s, p < 0.01), and the non-use of Perclose (manual compression or Angio-seal, p < 0.01). Multivariate analyses revealed that puncture site complications were significantly higher in patients with an ACT immediately before sheath removal ≥ 310 s (HR: 10.4, 95 % CI: 2.45–44.15, p < 0.01), scheduled treatment (HR: 10.16, 95 % CI: 1.81–56.95, p < 0.01), and the non-use of Perclose (HR: 21.97, 95 % CI: 2.42–199.34, p < 0.01). ConclusionA higher ACT immediately before sheath removal was significantly associated with puncture site complications. Perclose is an efficient device, and it may reduce the risk of puncture site complications.

Terapia endovascular en el tratamiento del ACV isquémico agudo. Perspectiva en Colombia

La aparición en este año de siete estudios que demuestran la superioridad de la terapia endovascular (TEV) sobre el tratamiento convencional de la trombólisis IV con t-PA en las primeras 4,5 horas posteriores al inicio del ataque cerebrovascular (ACV) isquémico agudo en pacientes con una obstrucción arterial proximal, establece un reto terapéutico para los neurólogos colombianos por el costo social que ocasiona la enfermedad y por las falencias que presenta nuestro sistema de salud para la atención óptima al respecto.&#x0D; Esta revisión crítica de los estudio MR Clean, Escape, Extend IA, Swift Prime, Revascat, Thrace y Therapy, así como de las guías 2015 de la American Heart Association (AHA), analizan la factibilidad e implementación de esta información en Colombia.&#x0D; La administración rápida de la terapia intravenosa con t-PA en estos estudios fortalece su implementación en el país e invita a generar protocolos que incluyan imágenes diagnósticas no invasivas como la angiografía cerebral por escanografía cerebral (CTA) o por resonancia magnética (MRA) que seleccionen a los pacientes con obstrucción proximal para brindarles lo más rápido posible el recurso de una TEV a través de una red hospitalaria del ACV.&#x0D; Los principales retos establecidos son los de allanar las diferencias entre el sector público y privado en la atención de pacientes con ACV isquémico agudo, dotar hospitales públicos con la tecnología y el talento humano que la TEV exige, e integrar una red nacional del ACV.

First-in-human trial of Center Wire for neuroendovascular therapy to avoid guidewire-related complications.

An exchange maneuver is useful for the delivery of devices to target vessels. However, hemorrhagic complications can occur due to vessel perforation during an exchange maneuver. In addition, the exchange is often challenging due to unfavorable anatomy. Center Wire is an exchange-length wire with a nondetachable stent that was developed to improve navigation and stability during exchange maneuvers. The aim of this study is to investigate the safety and efficacy of Center Wire of the anchor wire technique during neuroendovascular treatment. Ten patients with intracranial aneurysms were treated after signing a Certified Review Board-approved consent. Anchor wire technique was used in all patients to navigate catheters to the target vessel for aneurysm treatment. Anchor wire technique was successfully applied in all 10 cases using Center Wire. One device-related incident of vasospasm occurred which was asymptomatic. No device-related dissection, perforation, or thromboembolic events occurred. One patient had intraoperative aneurysm rupture during coil placement which was treated immediately without clinical consequences. Two patients had postoperative ischemic strokes due to thrombotic occlusion of branches originating from the aneurysm which were unrelated to the device. This first-in-human trial of Center Wire demonstrated the safety and efficacy of the anchor wire technique for neuroendovascular treatment in a strictly regulated prospective registry trial.

Factors for failure of ultrasound-guided compression repair for femoral pseudoaneurysms after neuroendovascular therapy.

Pseudoaneurysms are a serious complication of neuroendovascular therapy with femoral artery puncture, for which ultrasound-guided compression repair (UGCR) is often the first choice of radical therapy. We sought to retrospectively investigate the factors for failure of UGCR for pseudoaneurysm at the femoral artery puncture site. Among patients undergoing neuroendovascular therapy with femoral artery puncture at our hospital between January 2018 and April 2021, those who received a diagnosis of pseudoaneurysm and underwent UGCR were enrolled. They were classified into two groups according to whether UGCR was successful (UGCR group) or was converted to surgical repair (SR group). Patient and procedural characteristics were compared between the two groups. During the study period, 577 patients underwent neuroendovascular therapy with femoral artery puncture, 10 of whom (1.7%) received a diagnosis of pseudoaneurysm and underwent UGCR. There were seven patients in the UGCR group and three patients in the SR group. The sheath diameter tended to be larger in the SR group than in the UGCR group (p = 0.16). The modified Rankin scale score when a diagnosis of pseudoaneurysm was made was significantly lower in the SR group than in the UGCR group (1 [0-2] vs. 3 [2-5], p = 0.037). Physical activity may be associated with failure of UGCR. In patients with high physical activity, the use of sedatives and analgesics to keep them at rest during puncture site compression after UGCR may lead to successful UGCR.

Fragmentation of Hydrophilic Guidewire Coatings During Neuroendovascular Therapy.

Cerebral polymer coating embolism from intravascular devices may cause serious complications after endovascular therapy (EVT) for neurovascular diseases. Although polymer fragments are often created during endovascular procedures, exact mechanisms of their formation, especially if of small size, are largely unknown. In this study eight microguidewires (Asahi Chikai 200 cm(Asahi Intecc, Aichi, Japan), Asahi Chikai Black(Asahi Intecc), Fathom™(Boston Scientific, Marlborough, MA, USA), Hybrid(Balt Extrusion, Montmorency, France), Radifocus® Guide Wire GT(Terumo, Leuven, Belgium), Synchro2®(Stryker, Kalamazoo, MI, USA), Transend™ EX(Boston Scientific), and Traxcess™(MicroVention®, Tustin, CA, USA)) frequently used during EVT were investigated ex vivo using their dedicated metal or plastic insertion tools to assess for coating delamination after backloading of the microguidewires. Backloading caused damage to the coating of all microguidewires especially when the main body of the guidewires was bent in front of the insertion tool. All studied microguidewires produced microscopic filamentous and/or band-like coating fragments. Few larger irregular fragments were observed, but also very small fragments measuring1-3 µm in diameter were found. Spectroscopic measurements of polymer fragments and microguidewires identified various polymers. Backloading of polymer-coated microguidewires during EVT should be minimized if possible. More stable hydrophilic coatings on microguidewires and less traumatic insertion tools are desirable.

First-in-human trial of Stabilizer device in neuroendovascular therapy

ObjectivesFlow diverter or stent implantation to intracranial target lesion requires large inner diameter microcatheter navigation. The exchange method using stiff long wire is often necessary if it is difficult to navigate over the regular guidewire. However, this method has an intrinsic risk of vessel damage and may cause severe complications. We investigated the safety and efficacy of a new device, the Stabilizer device for navigation in a first-in-human clinical trial under the Certified Review Board agreement. Materials and methodsThe Stabilizer is a 320 cm length exchange wire with a stent for anchoring and is compatible with a 0.0165” microcatheter. The trial design is a prospective single-arm open-label registry. Inclusion criteria are elective flow diverter treatment or stent-assisted coiling, expected to be difficult to navigate a microcatheter with a regular micro guidewire, and obtained documented consent. The primary endpoint of the study was a hemorrhagic complication. ResultsFive patients were enrolled in this trial. The median age is 52 years, ranges from 41 to 70, and all patients were female. Three aneurysms were located on the internal carotid artery, one on the vertebral artery, and one on the basilar artery. Basilar artery aneurysm was treated by stent-assisted coiling and others were treated by flow diverter deployment. All cases successfully navigate microcatheter for the treatment by the trial method using Stabilizer device without any adverse event. ConclusionsThe results from this first-in-human consecutive five cases show the safety of the Stabilizer device in neuro-endovascular therapy for navigation of devices to the intracranial target lesion.

Carotid Artery Stenosis:Indications and Outcomes

Carotid artery stenting(CAS)has emerged as a less invasive alternative to carotid endarterectomy(CEA), the standard surgical treatment for carotid artery stenosis. Major international randomized control trials(RCTs)have demonstrated its non-inferiority to CEA, and it is now recommended in the Japanese stroke treatment guidelines for both symptomatic and asymptomatic severe stenotic lesions. To ensure safety, it is essential to use an embolic protection device to prevent ischemic complications and maintain the quality of physicians proficient in both techniques and devices. In Japan, these two essentials are guaranteed with the aid of a board certification system by the Japanese Society for Neuroendovascular Therapy. Furthermore, preprocedural carotid plaque evaluation using non-invasive methods such as ultrasonography and magnetic resonance imaging to detect vulnerable plaques, which are considered at high risk for embolic complications, is frequently performed, thereby determining therapeutic indications to avoid adverse events. Thus, the results of CAS in Japan are far superior to those of RCT abroad, making this procedure the first-line therapy for carotid revascularization for decades.

Training and Specialists Qualification System for Neuroendovascular Therapists in Japan

The specialist qualification system of the Japanese Society for Neuroendovascular Therapy was initiated in 2000. The qualified title is ranked as the technical specialist based on the fundamental clinical societies. After completing the training curriculum mainly programmed in the authorized institutes, the examinees are inspected with a triple-tiered comprehensive style using written, oral, and practical tests. Although the overall passing rate is not very high(50-60%), we are holding more than 1,700 specialists and 400 upper-level specialists designated as trainers and consultants in 2022. According to the definition of the organization of specialist authorization, enough knowledge and experience are required for the specialist to practice the standard treatments and offer adequate patient information. The education and training of the specialists are important duties for upper-level supervisors. In our qualification system, upper-level supervisors are strictly inspected and are requested to have a bigger potential to contribute to the development of the society and to take the lead on academic activity as well as clinical work. All qualified specialists should master "neuroendovascular therapeutics" and always brush up on themselves. In the recent rapid progress of our field, the effort to get the newest information about trends and consensus is essential to achieve the most effective and safest treatments.

A novel simulator-based checklist for evaluating residents' competence in cerebral angiography in China.

Nowadays, with the fast-increasing demand for neuro-endovascular therapy, surgeons in this field are in urgent need. Unfortunately, there is still no formal skill assessment in neuro-endovascular therapy in China. We used a Delphi method to design a newly objective checklist for standards of cerebrovascular angiography in China and evaluated its validity and reliability. A total of 19 neuro-residents with no interventional experience and 19 neuro-endovascular surgeons from two centers (Guangzhou and Tianjin) were recruited; they were divided into two groups: residents and surgeons. Residents completed a simulation-based cerebrovascular angiography operation training before assessment. Assessments were under live and video record forms with two tools: the existing global rating scale (GRS) of endovascular performance and the new checklist. The average scores of residents were significantly increased after training in two centers (p < 0.05). There is good consistency between GRS and the checklist (p = 0.856). Intra-rater reliability (Spearman's rho) of the checklist was >0.9, and the same result was also observed in raters between different centers and different assessment forms (p < 0.001, rho > 0.9). The reliability of the checklist was higher than that of the GRS (Kendall's harmonious coefficient is 0.849, while GRS is 0.684). The newly developed checklist appears reliable and valid for evaluating the technical performance of cerebral angiography and differentiating between trained and untrained trainees' performance well. For its efficiency, our method has been proven to be a feasible tool for resident angiography examination in certification nationwide.

Differences in gaze behaviors between trainees and experts during endovascular therapy for cerebral aneurysms: a preliminary study using a cerebral aneurysm model.

In the neuroendovascular field, the training of operators has become an important issue. Recently, eye-tracking technology has been introduced into various fields of medical education. This study aimed to apply eye-tracking technology to the training of neuroendovascular therapy. Six neurosurgeons, including three neuroendovascular specialists and three trainees, at our institution and related facilities participated in the study. Eye movement was recorded by the eye-tracking device during the microcatheter navigation and coil placement into the silastic aneurysm model under biplane X-ray fluoroscopy. Eye-tracking analysis during neuroendovascular therapy was feasible in all six subjects. In microcatheter navigation, specialists tended to more frequently switch their attention between frontal and lateral images than trainees. In coil embolization, the overall gaze frequency tended to increase, and the average fixation duration tended to decrease as the number of experienced cases increased. Inexperienced operators tend to fix their gaze when they are operators than when they are assistants. More experienced operators tended to look at the microcatheter longer in the coil insertion task. The eye-tracking analysis may be useful for operator training in neuroendovascular therapy. Experts may have moved their eyes more frequently than trainees to gaze at the right place. In the future, it will be necessary to collect gaze data for more operators in various tasks.