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.

Real-World Outcomes of Carotid Artery Stenting in Symptomatic and Asymptomatic Patients With Carotid Artery Stenosis.

BACKGROUND: The effectiveness and safety of carotid artery stenting (CAS) are comparable to those of carotid endarterectomy in both symptomatic and asymptomatic patients with carotid artery stenosis, but real-world outcomes are not well-known. OBJECTIVES: The purpose of this study was to investigate the real-world clinical outcomes of CAS in symptomatic and asymptomatic patients with carotid artery stenosis. METHODS: We conducted a nationwide retrospective registry study of 156 centers between January 2015 and December 2019. We enrolled consecutive patients with CAS managed by certified specialists from the Japanese Society of Neuroendovascular Therapy. Outcomes between symptomatic and asymptomatic patients were compared. The primary outcome was a composite of ischemic stroke and all-cause death at 30 days after CAS. Secondary outcomes were ischemic stroke, all-cause death, intracranial hemorrhage (ICH), and procedural complications. RESULTS: We analyzed 9,792 patients (symptomatic, n = 5,351; asymptomatic, n = 4,441). The mean age was 73.5 years, and men were dominant (86.4%). Embolism protection devices were used in 99% of patients. The primary outcome was not significantly different between the symptomatic and asymptomatic groups (120 [2.2%] vs 65 [1.5%]; adjusted OR: 1.30; 95% CI: 0.92-1.83). The incidences of symptomatic ICH, any ICH, acute in-stent occlusion, and hyperperfusion syndrome were significantly more prevalent in the symptomatic group (47 [0.9%] vs 8 [0.2%], aOR: 4.41 [95% CI: 1.68-11.6]; 73 [1.4%] vs 12 [0.3%], aOR: 3.56 [95% CI: 1.71-7.39]; 45 [0.8%] vs 19 [0.4%], aOR: 2.18 [95% CI: 1.08-4.40]; and 102 [1.9%] vs 36 [0.8%], aOR: 1.78 [95% CI: 1.17-2.71], respectively). Other secondary outcomes were not significantly different between the 2 groups. CONCLUSIONS: The complication rate after specialist-involved CAS at 30 days was low in real-world practice.

One-Stage Combined Open and Endovascular Treatment Using a Hybrid Operating Room is Safe and Effective for Distal Middle Cerebral Artery Aneurysms.

BACKGROUND: Aneurysms located in the distal middle cerebral artery (DMCA) are relatively rare and lack an established treatment strategy. For DMCA aneurysms, we performed a one-stage combined procedure of endovascular parent artery occlusion (PAO) with coils and superficial temporal artery to middle cerebral artery (STA-MCA) bypass in a hybrid operating room (HOR). The aim of this study was to evaluate the safety and efficacy of this procedure. METHODS: Cases of unruptured DMCA aneurysms treated with the one-stage combined PAO and STA-MCA bypass in HOR were retrospectively examined, and patients' and aneurysmal backgrounds, surgical procedures, and treatment outcomes were analyzed. RESULTS: Six patients were included in the study. The average maximum diameter of the aneurysms was 14.4 mm. One aneurysm was located at M2 and five at M3. All aneurysms had a fusiform shape. No cases were associated with infection, trauma, or malignant tumors. In all 6 cases, the combined PAO and STA-MCA bypass was successfully completed. No postoperative hemorrhagic complications occurred. A symptomatic ischemic complication occurred in 1 case whose symptom disappeared in a week. Three months after surgery, complete obliteration of the aneurysm and patency of the bypass was confirmed in all cases. CONCLUSIONS: The one-stage combined PAO and STA-MCA bypass in the HOR is safe and effective for DMCA aneurysms, potentially serving as a treatment option for this complex aneurysm.

Comorbidity burden and outcomes after mechanical thrombectomy for large vessel occlusion: A retrospective analysis.

OBJECTIVES: Patients with acute ischemic stroke (AIS) often have an accumulation of pre-existing comorbidities, but its clinical impact on outcomes after mechanical thrombectomy (MT) remains unknown. Therefore, we examined whether comorbidity burden before AIS onset could predict clinical outcomes after MT. METHODS: In this retrospective cohort, we enrolled consecutive patients with community-onset AIS who underwent MT between April 2016 and December 2021. To evaluate each patient's comorbidity burden, we calculated Charlson comorbidity index (CCI), then classified the patients into the High CCI (≥ 3) and the Low CCI (< 3) groups. The primary outcome was a good neurological outcome at 90 days, defined as a modified Rankin scale 0-2 or no worse than the previous daily conditions. All-cause mortality at 90 days and hemorrhagic complications after MT were also compared between the two groups. We estimated the odds ratios and their confidence intervals using a multivariable logistic regression model. RESULTS: A total of 388 patients were enrolled, of whom 86 (22.2%) were classified into the High CCI group. Patients in the High CCI group were less likely to achieve a good neurological outcome (adjusted odds ratio of 0.26 [95% confidence interval, 0.12-0.58]). Moreover, symptomatic intracranial hemorrhage was more common in the High CCI (14.0% vs. 4.6%; adjusted odds ratio, 4.10 [95% confidence interval, 1.62-10.3]). CONCLUSIONS: Comorbidity burden assessed by CCI was associated with clinical outcomes after MT. CCI has the potential to become a simple and valuable tool for predicting neurological prognosis among patients with AIS and MT.

Sex differences in outcomes of carotid artery stenting.

OBJECTIVE: Existing evidence is inconclusive on whether women after carotid artery stenting (CAS) experience worse outcomes than men. METHODS: The outcomes of women and men were compared using the data from nationwide retrospective registry between 2015 and 2019. The primary outcome was the incidence of ischemic stroke and all-cause death. Secondary outcomes included the incidence of ischemic stroke, all-cause death, acute occlusion, and acute myocardial infarction. Functional outcomes were the achieving an mRS score of 0-1 and 0-2. Outcomes were assessed at 30 days after CAS. RESULTS: In total, 9792 patients (1330 women, 8862 men; mean age, 73.8 vs 73.5 years, p = 0.17) were analyzed. Symptomatic stenosis was common in men (52.0% vs. 55.1%; p = 0.03), while ≥50% stenosis after CAS was common in women (3.2% vs. 2.0%; p = 0.005). The primary outcome was no significantly difference in women and men (2.0% vs. 1.9%; adjusted odds ratio [aOR], 1.19; 95% confidence interval [95%CI], 0.75-1.88).The incidence of all-cause death was higher in women (0.9% vs. 0.5%; aOR, 2.45; 95%CI, 1.11-5.39). Functional outcomes were significantly less common in women than in men (mRS0-1, 72.6% vs. 74.8%; aOR, 0.77; 95%CI, 0.63-0.95; mRS0-2, 82.1% vs. 85.6%; aOR, 0.76; 95%CI, 0.60-0.95). CONCLUSIONS: This study suggests that there was no significant sex differences in the incidence of ischemic stroke and all-cause death at 30 days. However, women have higher rate of all-cause death and poorer functional outcomes at 30 days than men.

A Review of Current Flow Diverters.

Flow diverter (FD) devices are new-generation stents placed in the parent artery at the aneurysmal neck to obstruct intra-aneurysmal blood flow, thus favoring intra-aneurysmal thrombosis. In Japan, about eight years have passed since health insurance approval was granted for FD devices, and FD placement to treat aneurysms has become widespread. Treatment indications have also been expanded with the introduction of novel devices. At present, three types of FD (Pipeline, FRED, and Surpass Streamline) are available in Japan. This report represents a compilation of available FD technologies and describes the current consensus on this treatment.

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

BACKGROUND: Endovascular 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). METHODS: We 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. RESULTS: Among 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]). CONCLUSIONS: Improvement in neurological severity after EVT was lower in patients with LVO and ICAD.

Treatment Results of Carotid Artery Stenting with an Open-Cell Stent: Analysis of 734 Consecutive Cases at a Single Center.

OBJECTIVE: In carotid artery stenting (CAS) for internal carotid artery stenosis, the stent is often selected according to the plaque properties and arterial tortuosity. In our institute, an open-cell stent is used as the first-line stent regardless of the characteristics of the lesion. This study was performed to examine the outcome of CAS with an open-cell stent as the real-world results. METHODS: In total, 811 CAS procedures using open-cell stents were performed for internal carotid artery stenosis from April 2002 to December 2019. Of these patients, we excluded those with hyperacute conditions for which CAS was performed within 3 days of onset, those in whom acute mechanical thrombectomy was performed simultaneously with CAS, and those with stenosis due to arterial dissection. Thus, 734 patients were retrospectively analyzed. Perioperative and long-term outcomes and risk factors for perioperative infarction were investigated. RESULTS: The periprocedural stroke rate and mortality rate were 3.7% (27/734) and 0.4% (3/734), respectively. Low-echoic plaque was a significant risk factor for periprocedural stroke in both univariate (P < 0.03) and multivariate (odds ratio, 2.69; 95% confidence interval, 1.14-6.66; P = 0.02) analyses. Cerebral infarction and high grade restenosis were observed in 15 (2.0%) and 17 (2.3%) patients during a median 50-month follow-up. CONCLUSIONS: CAS with open-cell stents showed good results in terms of both the postoperative stroke incidence and long-term severe restenosis rate. However, low-echoic plaque was a risk factor for perioperative stroke incidence, which should be considered when deciding on the indication for CAS with an open-cell stent.

Electrical impedance measurements can identify red blood cell-rich content in acute ischemic stroke clots ex vivo associated with first-pass successful recanalization.

Background: Electrochemical impedance spectroscopy can determine characteristics such as cell density, size, and shape. The development of an electrical impedance-based medical device to estimate acute ischemic stroke (AIS) clot characteristics could improve stroke patient outcomes by informing clinical decision making. Objectives: To assess how well electrical impedance combined with machine learning identified red blood cell (RBC)-rich composition of AIS clots ex vivo, which is associated with a successfully modified first-pass effect. Methods: A total of 253 clots from 231 patients who underwent thrombectomy in 5 hospitals in France, Japan, Serbia, and Spain between February 2021 and October 2023 were analyzed in the Clotbase International Registry. Electrical impedance measurements were taken following clot retrieval by thrombectomy, followed by Martius Scarlet Blue staining. The clot components were quantified via Orbit Image Analysis, and RBC percentages were correlated with the RBC estimations made by the electrical impedance machine learning model. Results: Quantification by Martius Scarlet Blue staining identified RBCs as the major component in clots (RBCs, 37.6%; white blood cells, 5.7%; fibrin, 25.5%; platelets/other, 30.3%; and collagen, 1%). The impedance-based RBC estimation correlated well with the RBC content determined by histology, with a slope of 0.9 and Spearman's correlation of r = 0.7. Clots removed in 1 pass were significantly richer in RBCs and clots with successful recanalization in 1 pass (modified first-pass effect) were richer in RBCs as assessed using histology and impedance signature. Conclusion: Electrical impedance estimations of RBC content in AIS clots are consistent with histologic findings and may have potential for clinically relevant parameters.

Technical and clinical outcomes of thrombectomy in patients with acute medium vessel occlusion and large vessel occlusion; sub-analyses of Japan Trevo registry.

BACKGROUND: Little is known about endovascular therapy (EVT) for patients with medium vessel occlusion (MeVO) and more work is needed to establish its efficacy and to understand hemorrhagic complications. METHODS: We analyzed the Japan Trevo Registry, which enrolled patients with acute stroke who underwent EVT using Trevo Retriever alone or in combination with an aspiration catheter. The primary outcome was effective reperfusion, and the secondary outcome was modified Rankin scale 0-2 at 90 days. Safety outcomes, including intracranial hemorrhage (ICH), were evaluated using a subgroup analyses focused on any ICH. RESULTS: Among 1041 registered patients, 1025 patients were analyzed. 253 patients had MeVOs, and the majority (89.3%) had middle cerebral artery segment 2 (M2). The median National Institutes of Health Stroke Scale scores at admission were 15 and 19 for the MeVO and LVO groups (p < 0.0001). The primary outcome was 88.9% in MeVO vs. 91.8% in LVO group: adjusted odds ratio (aOR) [95% confidence interval (CI)] 0.60 [0.35-1.03], p = 0.07, and the secondary outcome was 43.2% vs. 42.2%, and the aOR [95%CI] was 0.70 [0.48-1.002], p = 0.051. However, the incidence of any ICH was more prominent in MeVO than in LVO group (35.7% vs. 28.8%, aOR [95%CI] 1.54 [1.10-2.15], p = 0.01). In subgroup analyses, the incidences of any ICH in MeVO group were generally higher than those in LVO group. CONCLUSIONS: The effective reperfusion rate did not differ significantly between MeVO and LVO groups. Future development of devices and treatments for MeVO with fewer hemorrhagic complications is desirable.

Clinical evaluation of mechanical thrombectomy for patients with posterior circulation occlusion: A retrospective study.

OBJECTIVE: Although consensus has been reached regarding the use of mechanical thrombectomy for acute large anterior circulation occlusion, its effectiveness in patients with posterior circulation occlusion remains unclear. This study aimed to establish the determining factors for good clinical outcomes of mechanical thrombectomy for posterior circulation occlusion. METHODS: We extracted cases of acute large vessel occlusion (LVO) in the posterior circulation from a database comprising 536 patients who underwent mechanical thrombectomy at our hospital between April 2015 and March 2021. RESULTS: Fifty-two patients who underwent mechanical thrombectomy for LVO in the posterior circulation were identified. Five patients with simultaneous occlusion of the anterior and posterior circulation were excluded; finally, 47 patients were included in this study. The median patient age was 78 years, and 36% of the patients were women. The median National Institutes of Health Stroke Scale (NIHSS) score on admission was 31, the median posterior circulation-Alberta Stroke Program Early Computed Tomography Score (pc-ASPECTS) was 8, and the median Basilar Artery on Computed Tomography Angiography (BATMAN) score was 6. The rate of good recanalization (Thrombolysis in Cerebral Infarction scale grades 2b and 3) was 96%, and a good prognosis (modified Rankin Scale score of 0-2 at 90 days) was achieved in 19 patients (40%). The median pc-ASPECTS was significantly higher in the good prognosis group than in the poor prognosis group (10 vs. 7; p = 0.007). The median NIHSS score at presentation was significantly lower in the good prognosis group than in the poor prognosis group (17 vs. 34; p = 0.02). The median BATMAN score was significantly higher in the good prognosis group than in the poor prognosis group (8 vs. 3.5; p = 0.0002). Multivariate analysis showed that an NIHSS score ≦ 20 at presentation was the only independent factor for good prognoses. CONCLUSION: The prognosis of mechanical thrombectomy for posterior circulation LVO was better in patients with lower NIHSS scores at presentation.

Pathological changes in the lenticulostriate artery indicate the mechanisms leading to intracranial hemorrhage in Moyamoya disease: a case report.

This case report details the pathological findings of a vessel wall identified as the bleeding point for intracranial hemorrhage associated with Moyamoya disease. A 29-year-old woman experienced intracranial hemorrhage unrelated to hyperperfusion following superficial temporal artery-middle cerebral artery bypass surgery. A pseudoaneurysm on the lenticulostriate artery (LSA) was identified as the causative vessel and subsequently excised. Examination of the excised pseudoaneurysm revealed a fragment of the LSA, with a disrupted internal elastic lamina and media degeneration. These pathological findings in a perforating artery, akin to the circle of Willis, provide insights into the underlying mechanisms of hemorrhage in Moyamoya disease.

Impact of atherosclerotic etiology on technical and clinical outcomes of mechanical thrombectomy with a stent retriever: subanalysis of the Japan Trevo Registry.

BACKGROUND: The safety and effectiveness of stent retriever use for patients with acute large vessel occlusion (LVO) due to intracranial atherosclerotic disease (ICAD) is not well established. We investigated the differences in clinical outcomes in patients with and without ICAD. METHODS: We analyzed the Japan Trevo Registry, a nationwide registry which enrolled patients with acute LVO who underwent endovascular therapy (EVT) using the Trevo retriever alone or in combination with an aspiration catheter. We compared the technical and clinical outcomes of EVT between the ICAD and No-ICAD groups. The primary outcome was effective reperfusion and the secondary outcome was modified Rankin scale (mRS) score 0-2 at 90 days. Safety outcomes were worsening of neurologic symptoms within 24 hours, any intracranial hemorrhage within 24 hours, vessel dissection/vessel perforation related to using the Trevo retriever and mortality at 90 days. RESULTS: A total of 835 patients (45 in the ICAD group and 790 in the No-ICAD group) were analyzed. In the ICAD group, more men (68.9% vs 50.8%, P=0.02) and a lower median National Institutes of Health Stroke Scale score at admission (11 vs 18, P<0.0001) were observed. The primary outcome was significantly more common in the No-ICAD group (92.5%) than in the ICAD group (80.0%) (adjusted odds ratio (aOR) 0.21, 95% CI 0.09 to 0.50). The proportion of patients with mRS score 0-2 at 90 days was significantly lower in the ICAD group (44.4% vs 42.4%, aOR 0.49, 95% CI 0.23 to 1.00, P=0.0496). Other secondary and safety outcomes were not significantly different between the two groups. CONCLUSIONS: Patients with LVO with ICAD had a lower rate of effective reperfusion than those with No-ICAD.

Plaque Ulcerations are Associated with Recurrence in Symptomatic Low-Grade Carotid Stenosis.

OBJECTIVE: Surgical indications for low-grade carotid stenosis have not yet been established. This study aimed to clarify the characteristics of low-grade carotid stenosis refractory to medical treatment. METHODS: We retrospectively analyzed 48 patients with symptomatic low-grade carotid stenosis (<50%). Recurrence was defined as an ipsilateral ischemic event in the symptomatic lesions during the follow-up period. Patient demographics and imaging findings were compared between the recurrence and nonrecurrence groups to investigate risk factors associated with medical treatment. RESULTS: The mean age was 74.1 (58-90 years), and the mean follow-up period was 35.4 months (2.0-97 months). Recurrence occurred in 15 of the symptomatic patients. Ulceration was significantly associated with recurrence under medical treatment (P = 0.001). The median time to recurrence was 26.1 months in patients with ulcers and 54.3 months in those without ulcers (P = 0.04). Pathological study with recurrence showed plaque rupture with multilayered lesions, indicating lesions refractory to medical treatment. CONCLUSIONS: In cases of low-grade carotid stenosis, lesions with ulcerations are likely refractory to medical therapy. Consideration of the indications for surgical treatment may be warranted for lesions with ulceration, even if the degree of stenosis is low.

Irreversible postoperative cognitive impairment after unruptured intracranial aneurysm treatment in the elderly.

PURPOSE: Postoperative cognitive dysfunction and recovery remain unclear in older patients undergoing interventional therapies for unruptured intracranial aneurysms (UIAs). This study aimed to compare changes in postoperative cognitive function between younger and older patients and to detect factors associated with non-recovery from postoperative cognitive dysfunction. METHODS: This study reviewed 59 consecutive patients with UIAs who underwent interventional therapies, including microsurgical clipping or endovascular treatment, from 2021 to 2022. All patients were divided into the older (aged ≥ 70 years) and younger (aged < 70 years) groups. Mini-Mental State Examination (MMSE) and Frontal Assessment Battery (FAB) were performed within 2 months before interventions, at 1 week postoperatively (POW1), and 3-6 months postoperatively (POM3-6). RESULTS: MMSE and FAB scores decreased more frequently in the older group than in the younger group at POW1 (older vs. younger: MMSE: 48% vs. 21%, p < 0.05; FAB: 56% vs. 18%, p < 0.01). In the older group, the FAB Z-score decreased in POW1 and recovered by POM3-6 (p < 0.01), while the MMSE Z-score continued to decrease (p = 0.04). Age and the preoperative MSME Z-score were significantly associated with non-recovery from decreased MMSE score at POM3-6 (recovery vs. non-recovery, age: 62 years old vs. 72 years old, p = 0.03, preoperative MMSE Z-score: 0.16 vs. - 0.90, p < 0.01). CONCLUSIONS: This retrospective study found that older patients were more likely to have a postoperative cognitive decline after UIA treatment and implicated that global cognitive function tended to decline more than executive function in the long term. In addition, this study demonstrated that lower preoperative cognitive function was associated with inadequate postoperative cognitive recovery. The findings potentially contribute to the establishment of indications for treating UIAs in older patients.

Pipeline embolization device dynamics: prediction of incomplete occlusion by elongation from nominal length.

OBJECTIVE: According to benchtop studies, the oversizing of a Pipeline embolization device (PED) relative to the parent artery leads to a significant increase in porosity and potentially compromises aneurysm occlusion as well as transitional zone (TZ) formation around the neck of aneurysms. However, no clinical assessment has been reported. Here this potential was studied by measuring the dynamic changes of PEDs in the clinical time course. METHODS: The authors retrospectively examined 124 anterior circulation unruptured aneurysms in 114 consecutive patients treated with a PED between July 2015 and December 2020 at their institution. The authors excluded 77 cases of 68 patients with adjunctive coil embolization or multiple stents that could affect the PED dynamics and measurements, and 47 aneurysms in 46 patients were included. Measurements were performed before, immediately after, and 6 months after treatment, and then at intervals of 6 months to 1 year after that for nonocclusion cases. RESULTS: Complete occlusion was achieved in 79.0% and incomplete occlusion in 21.0% at last follow-up. The PED length immediately after deployment was 136% nominal length. A multivariable regression analysis revealed that age (OR 1.11/year; p = 0.02) and PED elongation from nominal length (OR 1.31/mm; p = 0.012) were independently associated with a higher rate of incomplete occlusion at the last follow-up. TZ formation did not affect the occlusion rate. CONCLUSIONS: PED elongation from the nominal length is a new predictor of incomplete aneurysm occlusion. The PED showed vascular remodeling by changing its diameter and length in the clinical course. TZ formation was remodeled and did not affect the occlusion rate.

First-in-human trial of a self-expandable, temporary dilation system for intracranial atherosclerotic disease in patients presenting with acute ischemic stroke.

BACKGROUND: Intracranial atherosclerotic disease (ICAD) significantly contributes to ischemic stroke, especially among Asian populations. Large vessel occlusion (LVO) due to underlying ICAD accounts for 15-35% of acute ischemic stroke cases requiring endovascular therapy. However, the successful recanalization rate of ICAD-related LVO remains lower. The TG dilator is a self-expandable device, temporarily dilating ICAD-related blocked blood vessels. OBJECTIVE: To demonstrate TG dilator safety and efficacy for ICAD-related acute ischemic stroke. METHODS: This was a single-arm, open-label, non-randomized, prospective, multicenter, and investigator-initiated trial that involved patients undergoing TG dilator application for acute ischemic stroke caused by ICAD-related LVO or severe stenosis. RESULTS: We enrolled 10 patients in this trial between November 2022 and April 2023. The median (IQR) age was 68 (59.3-75.3) years. Before using the dilator, seven patients received stent retriever treatment. All 10 patients were prescribed a loading dose of aspirin with prasugrel. The median application time was 10 (10-12) min. At the end of the procedure, we achieved significant recanalization immediately in all patients. The stenosis/occlusion decreased from 100% (100-100) to 68% (56.3-75.3). No patient experienced recurrent ischemic stroke or reocclusion within 90 days. We achieved a modified Rankin scale score of 0-2 in 8 patients by day 90. We detected no cases of intracranial hemorrhage, equipment failure, distal embolism, vasospasm, dissection, or perforation requiring intervention. CONCLUSIONS: Acute revascularization using the TG dilator on patients with ICAD-related LVO or severe stenosis did not cause any significant adverse event, and consistently improved blood flow at 90 days.

Impact of tailored multimodal treatment for unruptured brain arteriovenous malformation: comparison with a randomized trial of unruptured brain arteriovenous malformations.

PURPOSE: The first randomized controlled study on unruptured brain arteriovenous malformations (bAVM), the ARUBA trial, demonstrate the superiority of medical management; however, it failed to completely rule out the efficacy of therapeutic interventions due to several limitations. This study aimed to examine the outcomes of multimodal interventional treatment for bAVM in terms of safety and efficacy. METHODS: We reviewed 226 consecutive patients with unruptured bAVM admitted to our institute between 2002 and 2022. Treatment methods were divided into medical management and therapeutic intervention, including microsurgery, stereotactic surgery, and endovascular intervention. First, the choice of therapeutic modalities was assessed in the pre-ARUBA (before February 2014) and post-ARUBA (after March 2014) eras. Second, the incidence of symptomatic stroke or death and functional prognosis with a modified Rankin scale (mRS) score of ≥2 at 5 years was compared between the medical management and therapeutic intervention. RESULTS: In the pre- and post-ARUBA groups, 73% and 84% of patients underwent therapeutic interventions, respectively (p = 0.053). The rate of symptomatic stroke or death was lower in patients who underwent interventional therapies than in those who underwent medical management (9.7% vs. 22%, p = 0.022); however, the opposite was observed in the ARUBA trial (31% vs. 10%). The annual incidence of stroke or death was also lower in the interventional therapy group (4.3%/y vs. 1.8%/year, hazard ratio = 0.45, 95% confidence interval: 0.18-1.08, p = 0.032). The rate of mRS score of ≥2 after a 5-year follow-up was 18% and 6% in the medical treatment and intervention groups (p = 0.14). CONCLUSIONS: The therapeutic intervention rate did not decrease, even after the publication of the ARUBA trial. The rate of stroke or death was lower in the intervention group, indicating that a tailored choice of multimodality is safe and effective for managing unruptured bAVM.

Japan Trevo Registry: Real-world Registry of Stent Retriever Alone or in Combined Therapy with Aspiration Catheter for Acute Ischemic Stroke in Japan.

Endovascular therapy (EVT) for real-world patients after extended time frames is associated with concerns about its efficacy and safety. We conducted a prospective registry at 77 centers between November 2019 and October 2020. The registry criteria included patients treated with Trevo Retriever alone or in combined therapy with an aspiration catheter. The primary outcome was effective reperfusion (thrombolysis in cerebral infarction grade ≥ 2b), the secondary outcome was a modified Rankin scale 0-2 at 90 days, and the safety outcomes were worsening of neurologic symptoms within 24 h postoperatively, intracranial hemorrhage (ICH) within 24 h after EVT and mortality. We also exlpored the difference between patients whose last known well time (LKWT) to a puncture was less than 6 h (0-6 h) and those whose LKWT was 6 h or more but less than 24 h (6-24 h). Among the 1041 patients registered, 1025 patients were analyzed. The mean age was 76.9 years, and 53.6% of the participants were males. The 6-24 h group was 206/998 (20.6%), the median National Institute of Health Stroke Scale (NIHSS) score at admission was 18, and the median Alberta Stroke Program Early CT score was 8. Combined technique as the first pass was used on 817 (79.7%) patients. The primary outcome was 934 (91.1%). The secondary outcome was 433/1021 (42.4%). Symptomatic ICH, any ICH, and mortality were 10/1019 (1.0%), 311/1019 (30.5%), and 75 (7.3%). In the subanalysis, the 6-24 h group was lower in NIHSS (median;18 vs 16), and the secondary outcome was not significantly different in the <6 h group. Even after treatment time expansion, this result was comparable to other Trevo-based trials and nationwide registries.