[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.

Carotid Angioplasty and Stenting for Occlusive Diseases.

Stenting for carotid artery stenosis (CAS) was once denied 15 years ago because it failed to prove the non-inferiority to carotid endarterectomy (CEA). However, it is now reevaluated and is thought better due to higher safety and efficacy thanks to the development of devices, strategies, and various protection methods. To achieve the safe CAS, protection methods and stents should be properly selected based on the vessel course and plaque components on the preoperative plaque images. Particularly multiple protection methods including proximal balloon protection and double-layer micromesh stents are useful for the cases with high-risk and fragile plaque. Perioperative anti-platelet management and the control of blood pressure are also important to avoid the ischemic complications and hyperperfusion. Properly protected and tailored CAS based on the risk management has dramatically improved the clinical results and contributed to extend the indication for more difficult lesions.

Measuring Quality of Care for Ischemic Stroke Treated With Acute Reperfusion Therapy in Japan　- The Close The Gap-Stroke.

BACKGROUND: In Japan there is no consensus on how to efficiently measure quality indicators (QIs), defined as a standard of care, for acute ischemic stroke (AIS). Using information from a health insurance claims database and electronic medical records, we evaluated the feasibility and validity of measuring QIs for AIS patients who received intravenous recombinant tissue plasminogen activator (IV rt-PA) or endovascular therapy (EVT).Methods and Results:AIS patients receiving rt-PA or EVT between 2013 and 2015 were identified. We selected 17 AIS QI measures for primary stroke centers (PSCs) and 8 for comprehensive stroke centers (CSCs). Defined QIs were calculated for each hospital and then averaged. In total, the data of 8,206 patients (rt-PA 83.7%, EVT 34.9%) from 172 hospitals were obtained. Median National Institute of Health Stroke Scale score at admission was 14, and 37.7% of the patients were functionally independent at discharge. All target QIs were successfully measured with fewer missing values, and the accuracy of preset data was about 90%. Adherence rates were low (<50%) in 5 QI measures among PSCs, including door-to-needle time ≤1 h, and in 1 QI measure among CSCs (door-to-brain and vascular imaging time ≤30 min). CONCLUSIONS: Measuring QIs for AIS by this novel approach was feasible and reliable in the provision of a national benchmark.

Feasibility of underwater microvascular decompression for hemifacial spasm: a technical note.

BACKGROUND: We present a case series of underwater microvascular decompression (MVD) for hemifacial spasm (HFS) and an evaluation of its feasibility and safety. METHODS: This retrospective study was conducted at a single institution and included 20 patients with HFS who underwent underwater MVD between September 2019 and January 2021. Surgery was performed in 3 steps, as follows: exoscopic wound opening (soft tissue, bone, dura, and arachnoid around the cerebellomedullary cistern), underwater endoscopic surgery (decompression of the facial nerve), and exoscopic wound closure. In underwater endoscopic surgery, the surgical field was continuously irrigated with artificial cerebrospinal fluid. Abnormal muscle response and brainstem auditory evoked potentials (BAEPs) were monitored. RESULTS: Neurovascular conflicts were clearly observed in all patients without fogging and soiling of the endoscope lens. HFS was completely relieved in 19 patients (95%). An amplitude reduction of wave V of BAEPs of more than 50% was not observed in any of the cases. In 5 cases (25%), the latency of wave V of BAEPs was prolonged for more than 1.0 ms; these changes completely or near completely returned to baseline values at dural closure in all 5 cases. A postoperative complication of transient facial palsy was observed in 1 patient (5%) during postoperative days 10-30. There were no other complications. CONCLUSIONS: Our findings suggest that underwater MVD is a safe and feasible option for the treatment of HFS. However, it did not show advantages over conventional endoscopic MVD when the protective effect on the eighth cranial nerve was evaluated.

Standards of Practice in Acute Ischemic Stroke Intervention International Recommendations.

After five positive randomized controlled trials showed benefit of mechanical thrombectomy in the management of acute ischemic stroke with emergent large-vessel occlusion, a multi-society meeting was organized during the 17th Congress of the World Federation of Interventional and Therapeutic Neuroradiology in October 2017 in Budapest, Hungary. This multi-society meeting was dedicated to establish standards of practice in acute ischemic stroke intervention aiming for a consensus on the minimum requirements for centers providing such treatment. In an ideal situation, all patients would be treated at a center offering a full spectrum of neuroendovascular care (a level 1 center). However, for geographical reasons, some patients are unable to reach such a center in a reasonable period of time. With this in mind, the group paid special attention to define recommendations on the prerequisites of organizing stroke centers providing medical thrombectomy for acute ischemic stroke, but not for other neurovascular diseases (level 2 centers). Finally, some centers will have a stroke unit and offer intravenous thrombolysis, but not any endovascular stroke therapy (level 3 centers). Together, these level 1, 2, and 3 centers form a complete stroke system of care. The multi-society group provides recommendations and a framework for the development of medical thrombectomy services worldwide.

[Transarterial Embolization of Intraorbital Dural Arteriovenous Fistula:A Case Report].

Intraorbital dural arteriovenous fistula(dAVF)is a very rare disease; therefore, an optimal treatment strategy has not yet been established. Here, we describe a case of successful dAVF treatment by performing transarterial embolization(TAE)with n-butyl-2-cyanoacrylate(NBCA). A 66-year-old male presented with right conjunctival injection, with no history of trauma. Magnetic resonance imaging(MRI)demonstrated a flow void in the right orbit. Digital subtraction angiography(DSA)revealed an AVF fed by a branch of the right ophthalmic artery(OA)and draining into the dilated right superior ophthalmic vein(SOV). A transvenous embolization(TVE)was planned, but it could not be performed because the facial vein was meandering. Hence, TAE with NBCA was performed, and the AVF was successfully occluded by this method. There has been no recurrence of intraorbital dAVF in three months since the treatment. Several recent studies have reported that TAE is an effective treatment for intracranial dAVF. However, there are insufficient reports of TAE with NBCA for intraorbital dAVF treatment. The anatomy of the OA needs to be known for the success of TAE in treating intraorbital dAVF, because TAE is a high-risk treatment. In this paper, we report a case wherein TAE with NBCA was performed for intraorbital dAVF and further review the other treatment options.

Novel Technique for Rapid and Accurate Insertion of a Microguidewire Tail Into Low-Profile Devices During Endovascular Procedures: The Paper Rail Method.

PURPOSE: To report a novel technique ("paper rail") to facilitate inserting the tail of a microguidewire into the tip of a low-profile device during endovascular procedures. TECHNIQUE: A sterilized nonwoven fabric tape with a smooth glossy paper backing is used. The tape has several linear folds ideal for a paper rail. Holding each piece of equipment about 5 cm from its respective tip, both the tail of the guidewire and the tip of the catheter are navigated at a 30° angle toward each other in the crease until the guidewire enters the catheter. The paper rail technique was compared with the conventional freehand method under varying luminosities found in an operating room. The paper rail technique was most effective in suboptimal lighting, where the mean time was reduced from 83 seconds with the conventional method to 20 seconds with the paper rail maneuver. The times required to insert the wire with the paper rail method were comparable (~22 seconds) at all light levels. CONCLUSION: The paper rail method may help improve the speed and accurate insertion of the tail of a microguidewire into the tip of low-profile devices during endovascular procedures. It may be particularly useful for physicians in a low-light environment or trainees.

Continuous Blood Glucose Monitoring May Detect Carotid Occlusion Intolerance during Carotid Artery Stenting.

BACKGROUND: The frequency of the occurrence of adverse events associated with carotid artery stenting (CAS) is usually low, but serious adverse events such as cerebral hyperperfusion syndrome (CHS) may occur. Real-time monitoring is ideal for the early detection of adverse events during the surgical procedure. This study aimed to evaluate continuous blood glucose (BG) monitoring for the detection of adverse events during CAS. METHODS: Forty patients undergoing scheduled CAS were prospectively enrolled. An artificial pancreas was used for continuous BG monitoring (once per minute), using venous blood extracted at a rate of 2 mL/hr during CAS. The primary endpoint was a correlation between BG change and adverse events. RESULTS: CAS was discontinued in 1 patient, and BG was not measured in 5 patients (12.5%) because of the inability to extract blood. Among 34 evaluable patients, no patient developed CHS, but 3 patients (9%) experienced carotid occlusion intolerance. During CAS, BG was significantly higher in patients with carotid occlusion intolerance (median: 5 mg/dL) than in patients without carotid occlusion intolerance (median: 0 mg/dL) (P = 0.0221). A cutoff BG value ≥4 mg/dL during CAS showed 50% sensitivity and 100% specificity for the detection of carotid occlusion intolerance. There was no significant correlation between BG change and other adverse events. CONCLUSIONS: BG elevation may help detect carotid occlusion intolerance although it is still unknown whether BG monitoring can detect CHS. Further studies should validate that a cutoff BG elevation value of ≥4 mg/dL during CAS indicates carotid occlusion intolerance.

Association between CYP2C19 genotype and the additional effect of cilostazol to clopidogrel resistance in neuroendovascular therapy.

We investigated the association between CYP2C19 genotype and additional effect of cilostazol on clopidogrel resistance (CR) in neuroendovascular therapy. Between January 2012 and January 2016, 447 consecutive patients were administered with 75-mg cilostazol/day. The VerifyNow System was used for evaluating P2Y12 reaction units (PRU) > 230 and/or percentage inhibition of platelet function (% Inhibition) ≤ 20 as CR. Among 158 patients with CR, 31 were administered with additional 100- or 200-mg cilostazol/day and their platelet function was evaluated. According to CYP2C19 genotypes revealed using the Spartan RX and DNeasy Blood & Tissue Kit, patients were classified into three phenotypic groups: extensive metabolizer (EM, three patients), intermediate metabolizer (IM, 12 patients), and poor metabolizer (PM, 16 patients). Administration of additional cilostazol decreased PRU (EM group: 160.7 ± 85.2 after vs 278.3 ± 40.1 before, P = 0.15; IM group: 205.6 ± 74.0 vs 254.3 ± 35.0, P = 0.02; and PM group: 227.8 ± 52.2 vs 282.1 ± 30.4, P = 0.003), and increased % Inhibition (EM group: 40.0 ± 27.9 vs 9.3 ± 3.8, P = 0.25; IM group: 31.4 ± 18.0 vs 11.8 ± 8.2, P = 0.001; and PM group: 24.6 ± 15.0 vs 10.4 ± 9.3, P = 0.001). However, the rate of normalized-clopidogrel response, thromboembolic lesions, and bleeding complications were not significantly different among the three groups. Thus, the addition of cilostazol was effective on CR in terms of PRU, % Inhibition, rate of change of normalized-clopidogrel response, thromboembolic events, and bleeding complications irrespective of phenotype.

Posterior Meningeal Artery Origin Patterns among 300 Cases and Their Clinical Importance.

BACKGROUND AND PURPOSE: The posterior meningeal artery (PMA) is known as a dura mater-nourishing vessel. We encountered a patient with Wallenberg syndrome during transarterial embolization of the PMA associated with the dural arteriovenous fistula (DAVF). METHODS: After development of Wallenberg syndrome in the patient, we assessed origins of the PMA patterns in 300 cases and divided them into 3 types. CASE PRESENTATION: A 63-year-old man was incidentally diagnosed as having transverse-sigmoid sinus DAVF with a cortical venous reflux. During the transarterial embolization, the patient complained of vertigo and numbness of the right extremities. Postoperatively, the patient exhibited Wallenberg syndrome. Diffusion-weighted magnetic resonance imaging showed a high-intensity area on the lateral side of the right medulla. CONCLUSIONS: While performing arterial embolization of the PMA that directly originates from the intracranial vertebral artery, the possibility of deficient brainstem nourishment must be considered.

Novel Vertebral Artery Flow Reversal Method for Preventing Ischemic Complication during Endovascular Intervention.

BACKGROUND AND PURPOSE: We report a secure endovascular approach for the treatment of vascular lesions of the posterior circulation. Even if a large profile guide catheter is wedged in the unilateral vertebral artery (VA), our VA flow reversal method can prevent ischemic complications, including the spinal cord infarction. CASE PRESENTATION: The patient was a 64-year-old woman who had been followed up for arteriovenous malformation (AVM) and an unruptured aneurysm of the basilar artery-superior cerebellar artery bifurcation. Endovascular treatment was performed because minor bleeding occurred from the AVM. When a 6-French guide catheter was navigated into the right VA, the guide catheter became completely wedged, and blood flow between the tip of the catheter and the VA union was fully stagnated. Because ischemia of the anterior spinal artery and right posterior inferior cerebellar artery could persist for a few hours during the endovascular procedure, we built a continuous reversal circulation from the guiding catheter tip to the femoral vein. The flow stagnation disappeared immediately. There was no complication during embolization of both the AVM and aneurysm. CONCLUSIONS: The VA flow reversal method was secure in this case in which the tip of the guide catheter became wedged in the VA during the endovascular procedure.

Development and validation of a score for evaluating comprehensive stroke care capabilities: J-ASPECT Study.

BACKGROUND: Although the Brain Attack Coalition recommended establishing centers of comprehensive care for stroke and cerebrovascular disease patients, a scoring system for such centers was lacking. We created and validated a comprehensive stroke center (CSC) score, adapted to Japanese circumstances. METHODS: Of the selected 1369 certified training institutions in Japan, 749 completed an acute stroke care capabilities survey. Hospital performance was determined using a 25-item score, evaluating 5 subcategories: personnel, diagnostic techniques, specific expertise, infrastructure, and education. Consistency and validity were examined using correlation coefficients and factorial analysis. RESULTS: The CSC score (median, 14; interquartile range, 11-18) varied according to hospital volume. The five subcategories showed moderate consistency (Cronbach's α = 0.765). A strong correlation existed between types of available personnel and specific expertise. Using the 2011 Japanese Diagnosis Procedure Combination database for patients hospitalized with stroke, four constructs were identified by factorial analysis (neurovascular surgery and intervention, vascular neurology, diagnostic neuroradiology, and neurocritical care and rehabilitation) that affected in-hospital mortality from ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage. The total CSC score was related to in-hospital mortality from ischemic stroke (odds ratio [OR], 0.973; 95% confidence interval [CI], 0.958-0.989), intracerebral hemorrhage (OR, 0.970; 95% CI, 0.950-0.990), and subarachnoid hemorrhage (OR, 0.951; 95% CI, 0.925-0.977), with varying contributions from the four constructs. CONCLUSIONS: The CSC score is a valid measure for assessing CSC capabilities, based on the availability of neurovascular surgery and intervention, vascular neurology, diagnostic neuroradiology, and critical care and rehabilitation services.

Innovations in Endovascular Treatment Strategies for Large Carotid Cavernous Aneurysms-The Safety and Efficacy of a Flow Diverter.

BACKGROUND: The efficacy for the treatment of large carotid cavernous aneurysms (CCAs) was compared between conventional endovascular treatments, stent-assisted coiling (SAC), parent artery occlusion (PAO), and the flow diverter (FD). METHODS: Between January 2001 and December 2015, 49 patients with large, broad-necked, unruptured CCA underwent endovascular treatment at our institution. We performed PAO in 22 patients, SAC in 18 patients, and FD in 9 patients. Safety and efficacy were assessed in all patients by periodic clinical and radiological examinations during a 6-month follow-up. RESULTS: All 22 aneurysms treated with PAO disappeared immediately after treatment, but in the SAC-treated group, complete occlusion was obtained in only 5 of the 18 patients. All aneurysms in the FD group resulted in body filling. Perioperative ipsilateral temporary ischemic events occurred in 6 cases (PAO 4, SAC 2, FD 0). Delayed deterioration or new onset of cranial nerve symptoms was observed in 10 cases (PAO 3, SAC 3, FD 4), almost all of which recovered within 3 months. During the 6-month follow-up, all aneurysms treated with PAO showed a decrease in size without recanalization. In the SAC group, 12 aneurysms showed neck remnants, and marked recanalization occurred in 4 cases. Six of the 9 aneurysms in the FD group were completely occluded. CONCLUSIONS: The FD provided excellent final results despite transient worsening of symptoms. Although further long-term follow-up is essential, from a cost-effective and time-saving viewpoint, FD is a relatively safe and reliable method for the treatment of large CCAs.

One-Sided Headache Is a Symptom Suggesting Aneurysmal Lesion in Patients with Isolated Abducens Nerve Palsy.

An isolated unilateral abducens nerve palsy or headache alone usually yields negative findings on neuroimages. The authors report an individual with right abducens nerve palsy who developed a sudden, persistent headache on the right side. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) revealed a giant aneurysm of the cavernous carotid artery that was located along the course of the right abducens nerve. The findings in this case of isolated abducens nerve palsy suggest that headaches should be considered as important signs for intracranial aneurysmal lesions.

Successful recanalization for internal carotid artery occlusion with persistent primitive trigeminal artery manifesting only as ischemia of the posterior circulation.

BACKGROUND: Internal carotid artery (ICA) occlusion mainly manifests as ischemia of the anterior circulation. There are very few reports of ICA occlusion manifesting as only ischemia of the posterior circulation related to a fetal type posterior communicating artery or other arteries. CASE PRESENTATION: The authors experienced a case of ICA occlusion with persistent primitive trigeminal artery (PPTA) manifesting only as ischemia of the posterior circulation. In this case, the initial NIHSS score was high (35/42 points). Additionally, cross flow of the anterior communicating artery, ICA occlusion and basilar artery (BA) occlusion were represented on the initial head MRA. Therefore, our first impression was a presumptive diagnosis of BA occlusion. Prior head MRI/MRA performed for screening purposes, had incidentally demonstrated a right PPTA. Based on this understanding, we were able to determine the exact angioarchitectural mechanism of the ICA occlusion. Because of the presence of the PPTA, successful recanalization was accomplished expeditiously. CONCLUSION: Although the presence of PPTA is rare and ICA occlusion patients with PPTA is even more unusual, if ICA occlusion and BA occlusion appear simultaneously on MRA, the presence of PPTA should be considered.

Assessment of endovascular coil configuration for embolization of intracranial aneurysms using computational fluid dynamics.

Endovascular coil embolization of arterial aneurysms is often complicated by reduced blood flow to branching arteries. To determine the optimal coil configuration for safe embolization of endovascular aneurysms without compromising blood flow in branching arteries. A 3-dimensional voxel model, built based on an unruptured vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm, predicted to show impairment of flow in the PICA during endovascular coil embolization (Case 0). Six different models of final coil configuration were generated and applied to this aneurysm. Case 1 was a round coil mass. Case 2 was designed with a stent assist. Cases 3, and 4 were designed with a neck remnant and Cases 5 and 6 incorporated a balloon neck remodeling technique. Computational fluid dynamics was used to analyze the flow in the PICA in each model. The average outflow to the PICA was highest in Case 0 and lowest in Case 2 (in descending order, Case 0, 5, 4, 6, 1, 3, and 2). There was better preservation of outflow to the PICA in the balloon neck remodeling models than in the neck remnant models. In a model of endovascular coil embolization, we found considerable differences in outflow to the branching artery with small changes in coil configuration. Careful preoperative planning is important to minimize the risk of thromboembolic events during and after endovascular coil embolization.

Treatment of Symptomatic Bilateral Cavernous Carotid Aneurysms: Long-term Results of 6 Cases.

BACKGROUND: Bilateral cavernous carotid aneurysms (CCAs) are very rare. A treatment strategy for symptomatic bilateral CCAs has not been established because of their complex pathogenesis. Here we report our treatment strategy and long-term results for 6 cases of symptomatic bilateral CCAs. METHODS: From January 2007 to December 2013, we treated 6 patients (2 men and 4 women; mean age at first treatment, 56.0 years) with symptomatic bilateral CCAs. RESULTS: All patients began to experience unilateral symptoms. Five of the 6 underwent high-flow bypass (HFB) with parent artery occlusion (PAO), and 1 received PAO only. Mean follow-up period after the first treatment was 61.3 months. All symptoms improved after the treatment. Five contralateral CCAs became enlarged during the follow-up period. Of these, 4 became symptomatic. One patient received superficial temporal-middle cerebral artery bypass with PAO, 2 received HFB with PAO, and 1 refused treatment. Final modified Rankin Scale scores were 0 in 4 patients, 1 in 1 patient, and 2 in 1 patient. There was no mortality in this series. CONCLUSIONS: HFB with PAO is feasible as the first treatment for symptomatic bilateral CCAs. This treatment strategy steadies and simplifies future treatment of contralateral CCAs should they become symptomatic.

The impact of comprehensive stroke care capacity on the hospital volume of stroke interventions: a nationwide study in Japan: J-ASPECT study.

BACKGROUND: The association between comprehensive stroke care capacity and hospital volume of stroke interventions remains uncertain. We performed a nationwide survey in Japan to examine the impact of comprehensive stroke care capacity on the hospital volume of stroke interventions. METHODS: A questionnaire on hospital characteristics, having tissue plasminogen activator (t-PA) protocols, and 25 items regarding personnel, diagnostic, specific expertise, infrastructure, and educational components recommended for comprehensive stroke centers (CSCs) was sent to 1369 professional training institutions. We examined the effect of hospital characteristics, having a t-PA protocol, and the number of fulfilled CSC items (total CSC score) on the hospital volume of t-PA infusion, removal of intracerebral hemorrhage, and coiling and clipping of intracranial aneurysms performed in 2009. RESULTS: Approximately 55% of hospitals responded to the survey. Facilities with t-PA protocols (85%) had a significantly higher likelihood of having 23 CSC items, for example, personnel (eg, neurosurgeons: 97.3% versus 66.1% and neurologists: 51.3% versus 27.7%), diagnostic (eg, digital cerebral angiography: 87.4% versus 43.2%), specific expertise (eg, clipping and coiling: 97.2% and 54% versus 58.9% and 14.3%, respectively), infrastructure (eg, intensive care unit: 63.9% versus 33.9%), and education (eg, professional education: 65.2% versus 20.7%). On multivariate analysis adjusted for hospital characteristics, total CSC score, but not having a t-PA protocol, was associated with the volume of all types of interventions with a clear increasing trend (P for trend < .001). CONCLUSION: We demonstrated a significant association between comprehensive stroke care capacity and the hospital volume of stroke interventions in Japan.

Prospective registry of carotid artery stenting in Japan--investigation on device and antiplatelet for carotid artery stenting.

BACKGROUND: Carotid artery stenting (CAS) is minimally invasive but may cause perioperative cerebral infarction associated with distal embolization. We conducted a multicenter prospective observational study on the onset of vascular events after CAS to find out the efficacy and safety of CAS in Japan and to investigate the effects of antiplatelet drugs administered before and after CAS on efficacy and safety of CAS. METHODS: A total of 949 patients with cervical carotid artery stenosis were enrolled at 43 institutions in Japan; 934 who had undergone CAS with antiplatelet drugs and followed for 1 year were analyzed. Primary end point was the incidence of the first event of death, ischemic stroke, hemorrhagic stroke, transient ischemic attack, myocardial infarction, or serious hemorrhage within 1 year after enrollment. Comparison of the incidences of events according to antiplatelet drugs was also conducted. RESULTS: The primary end point was observed in 69 patients (7.4%) within 30 days of enrollment and in 40 patients (4.3%) between 31 days and 1 year after enrollment. The incidence of the first event for aspirin+cilostazol was significantly lower than that for aspirin+clopidogrel (P=.01), aspirin+clopidogrel+cilostazol (P=.01), and antiplatelet monotherapy (P<.01). Patient age (P=.01), presence of ischemic cerebrovascular disease (P=.02), presence of antidiabetic drugs (P<.01), femoral artery puncture (P=.02), guiding catheter used (P=.02), and Angioguard XP used (P=.01) were also correlated with the primary end point. CONCLUSION: Incidences of the primary end point within 30 days and 1 year of enrollment were comparable with previous reports, suggesting that CAS is a useful alternative for carotid endarterectomy in carotid stenosis patients with high risk for carotid endarterectomy. Further randomized controlled studies are needed to determine whether differences in mechanism of action of antiplatelet drugs might have contributed to the results of the present study.

Repeated Middle Cerebral Artery Occlusion Possibly Caused by Endoluminal Injury Due to Stent Clot Retriever: A Case Report.

In acute ischemic stroke, various endovascular approaches have been reported with high recanalization rates and good clinical outcomes. However, the best device or technique for the first attempt at mechanical thrombectomy remains a matter of debate. We report a case in which endoluminal injury from initial stent clot retrieval possibly caused repeated middle cerebral artery occlusion. A 74-year-old man presented with left-sided hemiplegia and was diagnosed with a right internal carotid artery occlusion. He underwent endovascular thrombectomy using a stent clot retriever. Although complete recanalization was achieved in the first pass, repeated middle cerebral artery occlusion occurred. Angiography revealed an irregular inner surface and thrombus formation in the superior branch of the second segment of the right middle cerebral artery. There is a risk of endoluminal injury due to stent retrieval, especially using a large sized stent against small branches. Antiplatelet therapy may be effective for preventing recurrent occlusion. Key Messages We report a case in which endoluminal injury from initial stent clot retrieval possibly caused repeated middle cerebral artery occlusion. There is a risk of endoluminal injury due to stent retrieval, especially using a large sized stent against nonvisible small branches.