Ichiro Nakahara

<sec id="sec001"> <title>Background and purpose</title> The impact of the paraoxonase-1 (<italic>PON1</italic>) polymorphism, Q192R, on platelet inhibition in response to clopidogrel remains controversial. We aimed to investigate the association between carrier status of <italic>PON1</italic> Q192R and high platelet reactivity (HPR) with clopidogrel in patients undergoing elective neurointervention. </sec> <sec id="sec002"> <title>Methods</title> Post-clopidogrel platelet reactivity was measured using a VerifyNow^® P2Y12 assay in P2Y12 reaction units (PRU) for consecutive patients before the treatment. Genotype testing was performed for <italic>PON1</italic> Q192R and <italic>CYP2C19*2</italic> and <italic>*3</italic> (no function alleles), and <italic>*17</italic>. PRU was corrected on the basis of hematocrit. We investigated associations between factors including carrying ≥1 <italic>PON1</italic> 192R allele and HPR defined as original and corrected PRU ≥208. </sec> <sec id="sec003"> <title>Results</title> Of 475 patients (232 men, median age, 68 years), HPR by original and corrected PRU was observed in 259 and 199 patients (54.5% and 41.9%), respectively. Carriers of ≥1 <italic>PON1</italic> 192R allele more frequently had HPR by original and corrected PRU compared with non-carriers (91.5% vs 85.2%, P = 0.031 and 92.5% vs 85.9%, P = 0.026, respectively). In multivariate analyses, carrying ≥1 <italic>PON1</italic> 192R allele was associated with HPR by original (odds ratio [OR] 1.96, 95% confidence interval [CI] 1.03–3.76) and corrected PRU (OR 2.34, 95% CI 1.21–4.74) after adjustment for age, sex, treatment with antihypertensive medications, hematocrit, platelet count, total cholesterol, and carrying ≥1 <italic>CYP2C19</italic> no function allele. </sec> <sec id="sec004"> <title>Conclusions</title> Carrying ≥1 <italic>PON1</italic> 192R allele is associated with HPR by original and corrected PRU with clopidogrel in patients undergoing elective neurointervention, although alternative results related to other genetic polymorphisms cannot be excluded. </sec>

PURPOSE: Endovascular treatment of posterior communicating artery aneurysms with fetal-type posterior communicating artery originating from the aneurysm dome is often challenging because, with conventional techniques, dense packing of aneurysms for posterior communicating artery preservation is difficult; moreover, flow-diversion devices are reportedly less effective. Herein, we describe a novel method called the λ stenting technique that involves deploying stents into the internal carotid artery and posterior communicating artery. METHODS: Between January 2018 and September 2020, the λ stenting technique was performed to treat eight consecutive cases of aneurysms. All target aneurysms had a wide neck (dome/neck ratio < 2), a fetal-type posterior communicating artery with hypoplastic P1, and a posterior communicating artery originating from the aneurysm dome. The origin of the posterior communicating artery from the aneurysm, relative to the internal carotid artery, was steep (< 90°: V shape). RESULTS: The maximum aneurysm size was 8.0 ± 1.9 mm (6-12 mm). The average packing density (excluding one regrowth case) was 32.7 ± 4.2% (26.8-39.1%). Initial occlusion was complete occlusion in 6 (75.0%) patients and neck remnants in 2 (25.0%) patients. Follow-up angiography was performed at 18.4 ± 11.6 months (3-38 months). There were no perioperative complications or reinterventions required during the study period. CONCLUSION: The λ stenting technique enabled dense coil packing and preservation of the posterior communicating artery. This technique enabled safe and stable coil embolization. Thus, it could become an alternative treatment option for this sub-type of intracranial aneurysms.

<sec> <title>Background and Purpose—</title> For patients with large vessel occlusion, neuroimaging biomarkers that evaluate the changes in brain tissue are important for determining the indications for mechanical thrombectomy. In this study, we applied deep learning to derive imaging features from pretreatment diffusion-weighted image data and evaluated the ability of these features in predicting clinical outcomes for patients with large vessel occlusion. </sec> <sec> <title>Methods—</title> This multicenter retrospective study included patients with anterior circulation large vessel occlusion treated with mechanical thrombectomy between 2013 and 2018. We designed a 2-output deep learning model based on convolutional neural networks (the convolutional neural network model). This model employed encoder-decoder architecture for the ischemic lesion segmentation, which automatically extracted high-level feature maps in its middle layers, and used its information to predict the clinical outcome. Its performance was internally validated with 5-fold cross-validation, externally validated, and the results compared with those from the standard neuroimaging biomarkers Alberta Stroke Program Early CT Score and ischemic core volume. The prediction target was a good clinical outcome, defined as a modified Rankin Scale score at 90-day follow-up of 0 to 2. </sec> <sec> <title>Results—</title> The derivation cohort included 250 patients, and the validation cohort included 74 patients. The convolutional neural network model showed the highest area under the receiver operating characteristic curve: 0.81±0.06 compared with 0.63±0.05 and 0.64±0.05 for the Alberta Stroke Program Early CT Score and ischemic core volume models, respectively. In the external validation, the area under the curve for the convolutional neural network model was significantly superior to those for the other 2 models. </sec> <sec> <title>Conclusions—</title> Compared with the standard neuroimaging biomarkers, our deep learning model derived a greater amount of prognostic information from pretreatment neuroimaging data. Although a confirmatory prospective evaluation is needed, the high-level imaging features derived by deep learning may offer an effective prognostic imaging biomarker. </sec>

BACKGROUND: The long-term outcomes of patients with intraprocedural aneurysm rupture (IPR) during endovascular coiling of unruptured intracranial aneurysms (UIAs) remain unclear. We investigated the long-term outcomes and predictors of neurological outcomes in patients who sustained IPR during coil embolization of UIAs. METHODS: We retrospectively analyzed the medical record of 312 untreated UIAs in 284 patients who underwent endovascular coiling between April 2013 and July 2018. RESULTS: The mean follow-up period for the entire cohort was 25.6 months. Twelve patients (3.8%) experienced IPR. The mean aneurysm size in the IPR cohort was significantly smaller than that in the no-IPR cohort (P = 0.045). The IPR cohort had a higher percentage of earlier subarachnoid hemorrhage from another aneurysm (P = 0.019), anterior communicating artery (AComA) aneurysm (P < 0.001), and basilar artery (BA) aneurysm (P = 0.022) than the no-IPR cohort. Neurologic deterioration was observed in 3 patients. The morbidity and mortality rates of the IPR cohort were 25% and 8.3%, respectively. Patients with IPR during coil embolization for AComA aneurysm did not develop neurological deterioration. Two of the 3 patients (66.7%) with a BA aneurysm had neurological deterioration. The proportion of patients with an mRS score of 0-2 at the last follow-up did not differ between the 2 cohorts (P = 0.608). CONCLUSIONS: The proportion of functionally independent patients did not differ between patients with and without IPR. Patients with BA aneurysms who developed an IPR tended to exhibit more unfavorable clinical courses than patients with AcomA aneurysms.

OBJECTIVE: To identify a proximal anterior circulation occlusion for effectively administering immediate mechanical thrombectomy by developing a novel, simple diagnostic scale to predict the occlusion, to compare its validity with available scales, and to assess its utility. METHODS: To develop a novel clinical scale, we retrospectively analyzed a cohort of 429 patients with acute ischemic stroke from a single center. The novel scale GAI2AA was applied to a prospective cohort of 259 patients from 3 stroke centers for external validation. The utility of the scale as an in-hospital triage was compared for the temporal factors of 158 patients with the occlusion. RESULTS: In a scale-developmental phase, those with a proximal anterior circulation occlusion had significantly more frequent signs of hemispheric symptoms, including gaze palsy, aphasia, inattention, arm paresis, and atrial fibrillation. The GAI2AA scale was developed using consolidated hemispheric symptoms and was scored as follows: score = 2, arm paresis score = 1, and atrial fibrillation score = 1. A cutoff value ≥3 was optimal for the correlation between sensitivity (88%) and specificity (81%), with a C statistic of 0.90 (95% confidence interval 0.87-0.93). External validation indicated that discrimination was significantly better than or not different from that of available complex scales. Door-to-puncture time was significantly reduced (91 [82-111] vs 52 [32-75] minutes, p < 0.001). CONCLUSION: The GAI2AA scale showed high sensitivity and specificity when an optimal cutoff score was used and was useful as an in-hospital triage tool.

Background: To maximize the effect of intravenous (IV) thrombolysis and/or endovascular therapy (EVT) for acute ischemic stroke (AIS), stroke centers need to establish a parallel workflow on the basis of a code stroke (CS) protocol. At Kokura Memorial Hospital (KMH), we implemented a CS system in January 2014; however, the process of information sharing within the team has occasionally been burdensome. Objective: To solve this problem using information communication technology (ICT), we developed a novel application for smart devices, named "Task Calc. Stroke" (TCS), and aimed to investigate the impact of TCS on AIS care. Methods: TCS can visualize the real-time progress of crucial tasks for AIS on a dashboard by changing color indicators. From August 2015 to March 2017, we installed TCS at KMH and recommended its use during normal business hours (NBH). We compared the door-to-computed tomography time, the door-to-complete blood count (door-to-CBC) time, the door-to-needle for IV thrombolysis time, and the door-to-puncture for EVT time among three treatment groups, one using TCS ("TCS-based CS"), one not using TCS ("phone-based CS"), and one not based on CS ("non-CS"). A questionnaire survey regarding communication problems was conducted among the CS teams at 3 months after the implementation of TCS. Results: During the study period, 74 patients with AIS were transported to KMH within 4.5 h from onset during NBH, and 53 were treated using a CS approach (phone-based CS: 26, TSC-based CS: 27). The door-to-CBC time was significantly reduced in the TCS-based CS group compared to the phone-based CS group, from 31 to 19 min (p = 0.043). Other processing times were also reduced, albeit not significantly. The rate of IV thrombosis was higher in the TCS-based CS group (78% vs. 46%, p = 0.037). The questionnaire was correctly filled in by 34/38 (89%) respondents, and 82% of the respondents felt a reduction in communication burden by using the TCS application. Conclusions: TCS is a novel approach that uses ICT to support information sharing in a parallel CS workflow in AIS care. It shortens the processing times of critical tasks and lessens the communication burden among team members.

OBJECTIVELong-term follow-up results of the treatment of unruptured intracranial aneurysms (UIAs) by means of coil embolization remain unclear. The aim of this study was to analyze the frequency of rupture, retreatment, stroke, and death in patients with coiled UIAs who were followed for up to 20 years at multiple stroke centers.METHODSThe authors retrospectively analyzed data from cases in which patients underwent coil embolization between 1995 and 2004 at 4 stroke centers. In collecting the late (≥ 1 year) follow-up data, postal questionnaires were used to assess whether patients had experienced rupture or retreatment of a coiled aneurysm or any stroke or had died.RESULTSOverall, 184 patients with 188 UIAs were included. The median follow-up period was 12 years (interquartile range 11-13 years, maximum 20 years). A total of 152 UIAs (81%) were followed for more than 10 years. The incidence of rupture was 2 in 2122 aneurysm-years (annual rupture rate 0.09%). Nine of the 188 patients with coiled UIAs (4.8%) underwent additional treatment. In 5 of these 9 cases, the first retreatment was performed more than 5 years after the initial treatment. Large aneurysms were significantly more likely to require retreatment. Nine strokes occurred over the 2122 aneurysm-years. Seventeen patients died in this cohort.CONCLUSIONSThis study demonstrates a low risk of rupture of coiled UIAs with long-term follow-up periods of up to 20 years. This suggests that coiling of UIAs could prevent rupture for a long period of time. However, large aneurysms might need to be followed for a longer time.

Kakumoto K, Matsumoto S, Nakahara I, Watanabe Y, Fukushima Y, Yoshikiyo U, Ishibashi R, Gomi M, Tsuji K, Sanbongi Y, Hashimoto T, Tanaka Y, Yamada T, Kira J, Cerebrovascular diseases extra, 2012, vol. 2, no. 1, pp. 9-16