Deep Learning-Derived High-Level Neuroimaging Features Predict Clinical Outcomes for Large Vessel Occlusion.

Background and Purpose- 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. Methods- 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. Results- 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. Conclusions- 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.

Predicting Clinical Outcomes of Large Vessel Occlusion Before Mechanical Thrombectomy Using Machine Learning.

Background and Purpose- The clinical course of acute ischemic stroke with large vessel occlusion (LVO) is a multifactorial process with various prognostic factors. We aimed to model this process with machine learning and predict the long-term clinical outcome of LVO before endovascular treatment and to compare our method with previously developed pretreatment scoring methods. Methods- The derivation cohort included 387 LVO patients, and the external validation cohort included 115 LVO patients with anterior circulation who were treated with mechanical thrombectomy. The statistical model with logistic regression without regularization and machine learning algorithms, such as regularized logistic regression, linear support vector machine, and random forest, were used to predict good clinical outcome (modified Rankin Scale score of 0-2 at 90 days) with standard and multiple pretreatment clinical variables. Five previously reported pretreatment scoring methods (the Pittsburgh Response to Endovascular Therapy score, the Stroke Prognostication Using Age and National Institutes of Health Stroke Scale index, the Totaled Health Risks in Vascular Events score, the Houston Intra-Arterial Therapy score, and the Houston Intra-Arterial Therapy 2 score) were compared with these models for the area under the receiver operating characteristic curve. Results- The area under the receiver operating characteristic curve of random forest, which was the worst among the machine learning algorithms, was significantly higher than those of the standard statistical model and the best model among the previously reported pretreatment scoring methods in the derivation (the area under the receiver operating characteristic curve were 0.85±0.07 for random forest, 0.78±0.08 for logistic regression without regularization, and 0.77±0.09 for Stroke Prognostication using Age and National Institutes of Health Stroke Scale) and validation cohorts (the area under the receiver operating characteristic curve were 0.87±0.01 for random forest, 0.56±0.07 for logistic regression without regularization, and 0.83±0.00 for Pittsburgh Response to Endovascular Therapy). Conclusions- Machine learning methods with multiple pretreatment clinical variables can predict clinical outcomes of patients with anterior circulation LVO who undergo mechanical thrombectomy more accurately than previously developed pretreatment scoring methods.

Cerebral Venous Thrombosis after Red Blood Cell Transfusion for the Treatment of Iron Deficiency Anemia.

A 57-year-old male presented with generalized seizure who received red blood cell (RBC) transfusion for the treatment of iron deficiency anemia (IDA). Neuroradiological findings revealed cerebral venous thrombosis (CVT) on the left frontal vein. He received anticoagulants, anticonvulsants, and iron supplements. He discharged without any neurological deficit. It should be noted that RBC transfusion might increase the risk of CVT in patients with IDA.

Healthcare resource utilization and clinical outcomes associated with acute care and inpatient rehabilitation of stroke patients in Japan.

OBJECTIVE: To investigate healthcare resource utilization and changes in functional status in stroke patients during hospitalization in an acute hospital and a rehabilitation hospital. DESIGN: Retrospective cohort study. SETTING: One acute and one rehabilitation hospital in Japan. PARTICIPANTS: Patients who were admitted to the acute hospital due to stroke onset and then transferred to the rehabilitation hospital (n = 263, 56% male, age 70 ± 12 years). MAIN OUTCOME MEASURES: Hospitalization costs and functional independence measure (FIM) were evaluated according to stroke subtype and severity of disability at discharge from the acute hospital. RESULTS: Median (IQR) costs at the acute hospital were dependent on the length of stay (LOS) and implementation of neurosurgery, which resulted in higher costs in subarachnoid hemorrhage [$52 413 ($49 166-$72 606) vs $14 129 ($11 169-$19 459) in cerebral infarction; and vs $15 035 ($10 920-$21 864) in intracerebral hemorrhage]. The costs at the rehabilitation hospital were dependent on LOS, and higher in patients with moderate disability than in those with mild disability [$30 026 ($18 419-$39 911) vs $18 052 ($10 631-$24 384)], while those with severe disability spent $25 476 ($13 340-$43 032). Patients with moderate disability gained the most benefits during hospitalization in the rehabilitation hospital, with a median (IQR) total FIM gain of 16 (5-24) points, compared with a modest improvement in patients with mild (6, 2-14) or severe disability (0, 0-5). CONCLUSIONS: The costs for in-hospital stroke care were substantial and the improvement in functional status varied by severity of disability. Our findings would be valuable to organize efficient post-acute stroke care.

Milrinone via lumbar subarachnoid catheter for vasospasm after aneurysmal subarachnoid hemorrhage.

INTRODUCTION: Delayed ischemic neurological deficit (DIND) due to symptomatic vasospasm is a major cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study was to elucidate the safety and feasibility of intrathecal milrinone infusion via lumber subarachnoid catheter for prevention of DIND after aSAH. METHODS: We diagnosed 425 consecutive patients with aSAH who received clipping or coil embolization within 48 h after arrival. Patients with the evidence of vasospasm on CT angiography (CTA) received the milrinone therapy via lumbar subarachnoid catheter. DIND, delayed cerebral infarction (DCI), and modified Rankin scale at 3 months after SAH were used for the assessment of outcome. RESULTS: Of 425 patients, 170 patients (40.0 %) with CTA-proven vasospasm received the milrinone therapy. DIND was observed in 68 patients (16.0 %), DCI in 30 patients (7.1 %), and the overall mortality was 7.2 %. In patients with WFNS grade IV and V aSAH, 26 out of 145 patients (17.9 %) were presented with DIND, 12 (8.3 %) with DCI, and the mortality was 16.0 %. No major complication related to the milrinone injection was observed. CONCLUSION: Intrathecal milrinone injection via lumbar catheter was safe and feasible, and further randomized prospective studies are needed to confirm the effectiveness of this regimen in the patients with SAH.

Cerebral Venous Sinus Thrombosis Associated With Subclinical Hypothyroidism: A Case Report and Literature Review.

Thyroid dysfunction is a well-known cause of cerebral venous sinus thrombosis (CVST), but most reports have focused on CVST associated with hyperthyroidism, with only a few mentioning CVST associated with hypothyroidism. Subclinical hypothyroidism, characterized by thyroid hormone levels within reference values but elevated thyroid-stimulating hormone, can also cause CVST. Here, we present a case of CVST associated with subclinical hypothyroidism. A 48-year-old man with headache, nausea, and left-sided motor weakness was admitted to our hospital, with a history of economy-class syndrome. Magnetic resonance imaging revealed occlusion of the superior sagittal sinus, right transverse sinus, and right sigmoid sinus. Digital subtraction angiography (DSA) confirmed CVST from the right common carotid artery, revealing abnormal staining of the thyroid gland. The patient was serologically in a state of subclinical hypothyroidism. Consequently, the patient was diagnosed with CVST associated with subclinical hypothyroidism. Anticoagulation therapy was initiated shortly after admission. CVST gradually resolved, and the affected sinuses were recanalized. Paraplegia improved, and the patient was discharged home 19 days after admission with a modified Rankin scale of 1. Subclinical hypothyroidism can induce CVST, underscoring the importance of screening for thyroid function in CVST patients, even without apparent thyroid dysfunction symptoms. DSA findings are valuable for diagnosing thyroid disease.

[Cost Comparison of Carotid Endarterectomy versus Carotid Stenting in Japan].

Carotid artery stenting (CAS) has been covered by the health insurance system in Japan since 2008. There have been few studies concerning medical costs and charges for patients who received CEA or CAS in Japan. The aim of this study was to elucidate the difference in the costs between the patients who received CEA and those who received CAS in Japan. Between 2010 and 2011, 19 patients who received CEA and 20 patients who received CAS were retrospectively reviewed. Age, sex, symptomatic/asymptomatic, emergent/scheduled, length of stay, outcome, cost for the procedure (professional fee), supply for the operation, the total medical service fee, and copayment of the patients was compared between the two treatment groups. No significant difference was detected between the two groups except for the supply of the operation and the total medical service fee (CEA:mean 1,565,580 yen vs CAS 2,758,360 yen, p=0.0001). On the other hand, no significant difference was obtained in the copayment of the patients (CEA 71,895 yen, CAS 72,458 yen). Even when limited to the scheduled cases, similar results were obtained. There is a monthly copayment limit in the health insurance system in Japan, which results in a reasonable charge for patients who received CAS, despite the fact that the rest of the fee including high costs for the supplies was paid by the company and the nation. To reduce the medical costs, Japanese have to be aware of the high costs in CAS, most of which is due to the supplies.

Traumatic middle meningeal arteriovenous fistula presenting with long delayed-onset facial nerve palsy without temporal bone fracture: illustrative case.

BACKGROUND: Traumatic facial nerve palsy (FNP) without temporal bone fracture (TBF) has a delayed onset in some cases; however, long delayed-onset FNP in this setting has not been reported. The middle meningeal vein (MMV) is one of the venous drainage routes from the facial nerve. Herein, the authors describe a rare case of traumatic middle meningeal arteriovenous fistula (MMAVF) presenting with the long delayed-onset FNP without TBF. OBSERVATIONS: A 42-year-old man with pulsatile tinnitus and left FNP was admitted to our hospital 4 weeks after head trauma without TBF. Cerebral angiography revealed an MMAVF between the middle meningeal artery and the MMV on the left side. Seven days after admission, the FNP showed slight improvement, and preoperative angiography revealed decreased shunt flow of the MMAVF. Transarterial coil embolization was successfully performed. Postoperative angiography showed no residual fistula. Two weeks after the procedure, there was complete resolution of the FNP. This clinical course was correlated with the angiographic findings, suggesting that the long delayed-onset FNP was caused by the traumatic MMAVF without TBF. LESSONS: In patients presenting with long delayed-onset FNP after head trauma without TBF, the vascular lesion must be evaluated to exclude MMAVF.

PON1 Q192R is associated with high platelet reactivity with clopidogrel in patients undergoing elective neurointervention: A prospective single-center cohort study.

BACKGROUND AND PURPOSE: The impact of the paraoxonase-1 (PON1) polymorphism, Q192R, on platelet inhibition in response to clopidogrel remains controversial. We aimed to investigate the association between carrier status of PON1 Q192R and high platelet reactivity (HPR) with clopidogrel in patients undergoing elective neurointervention. METHODS: 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 PON1 Q192R and CYP2C19*2 and *3 (no function alleles), and *17. PRU was corrected on the basis of hematocrit. We investigated associations between factors including carrying ≥1 PON1 192R allele and HPR defined as original and corrected PRU ≥208. RESULTS: 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 PON1 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 PON1 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 CYP2C19 no function allele. CONCLUSIONS: Carrying ≥1 PON1 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.

Clopidogrel response predicts thromboembolic events associated with coil embolization of unruptured intracranial aneurysms: A prospective cohort study.

OBJECTIVE: Periprocedural thromboembolic events are a serious complication associated with coil embolization of unruptured intracranial aneurysms. However, no established clinical rule for predicting thromboembolic events exists. This study aimed to clarify the significance of adding preoperative clopidogrel response value to clinical factors when predicting the occurrence of thromboembolic events during/after coil embolization and to develop a nomogram for thromboembolic event prediction. METHODS: In this prospective, single-center, cohort study, we included 345 patients undergoing elective coil embolization for unruptured intracranial aneurysm. Thromboembolic event was defined as the occurrence of intra-procedural thrombus formation and postprocedural symptomatic cerebral infarction within 7 days. We evaluated preoperative clopidogrel response and patients' clinical information. We developed a patient-clinical-information model for thromboembolic event using multivariate analysis and compared its efficiency with that of patient-clinical-information plus preoperative clopidogrel response model. The predictive performances of the two models were assessed using area under the receiver-operating characteristic curve (AUC-ROC) with bootstrap method and compared using net reclassification improvement (NRI) and integrated discrimination improvement (IDI). RESULTS: Twenty-eight patients experienced thromboembolic events. The clinical model included age, aneurysm location, aneurysm dome and neck size, and treatment technique. AUC-ROC for the clinical model improved from 0.707 to 0.779 after adding the clopidogrel response value. Significant intergroup differences were noted in NRI (0.617, 95% CI: 0.247-0.987, p < .001) and IDI (0.068, 95% CI: 0.021-0.116, p = .005). CONCLUSIONS: Evaluation of preoperative clopidogrel response in addition to clinical variables improves the prediction accuracy of thromboembolic event occurrence during/after coil embolization of unruptured intracranial aneurysm.

[Trends in mortality rates for subarachnoid hemorrhage, from 1999 through 2008: single center experience].

We retrospectively reviewed the mortality rate of the patients with subarachnoid hemorrhage (SAH) who received initial treatment in Kurashiki Central Hospital, for the 10-year period from 1999 through 2008. The overall mortality was 18.1% (120/662). The average fatality rate in such cases has shown a decreasing trend, from 24.2% in 1999-2002 to 15.9% in 2005-2008 (p=0.016). Transition in initial diagnostic modality from the time-consuming digital subtraction angiography to the less-invasive computed tomographic angiography, appropriate indication for the operation, and improvement in postoperative management might affect this decline in fatality cases.

[Strategy for revascularization of chronic carotid occlusion with contralateral carotid stenosis].

BACKGROUND AND PURPOSE: The optimal therapeutic approach for chronic carotid occlusion with contralateral carotid stenosis (ICO-ICS) remains uncertain. The aim of this study was to elucidate the safety and efficacy of initial vascular reconstruction for ICS in patients with ICO-ICS. PATIENTS AND METHODS: Eleven patients with ICO-ICS who demonstrated severe cerebral hypoperfusion in the hemisphere ipsilateral to ICO were treated in our institution between February 2003 and November 2007. Revascularization for ICS after measuring cerebral blood flow (CBF) by single photon emission computed tomography (SPECT) was performed either by carotid endarterectomy or carotid stenting. External carotid artery-internal carotid artery (EC-IC) bypass for ICO was also performed when SPECT after revascularization for ICS still demonstrated marked hypoperfusion. RESULTS: In 6 patients with collateral flow via the anterior communicating artery and/or who had high-grade ICS (>70%), sufficient improvement of CBF solely by revascularization for ICS was confirmed. With regard to perioperative complications, 2 patients suffered bradycardia and hypotension and another 2 showed asymptomatic cerebral infarction on diffusion-weighted magnetic resonance imaging. CONCLUSIONS: Overall results for revascularization of ICS prior to that for ICO in patients with ICO-ICS were acceptable. CBF of bilateral hemispheres was sufficiently improved in more than half of the patients solely by revascularization for ICS. This strategy might be both efficient and effective for ICO-ICS.

[Detection of intraplaque hemorrhage with use of screening black-blood MRI].

The evaluation of plaque characteritics as well as the degree of luminal narrowing is important in the management of carotid stenosis. Several reports have shown that intraplaque hemorrhage (IPH), which plays a pivotal role in plaque vulnerability, emits high signal intensity on T1-weighted images of high-resolution black-blood (BB) MRIs. When an MRI is used to screen for vulnerable plaque, a short scanning duration and a simple MRI protocol are required. This study assessed the utility of screening BB-MRI to detect IPH. Ninety-three consecutive cases with atherosclerotic carotid stenosis scheduled for carotid endarterectomy (CEA) or carotid artery stenting between January 2005 and December 2007 were included. High-resolution BB-MRI scans were obtained with 2D double-inversion recovery fast spin-echo sequences with cardiac gating. Screening BB-MRIs were performed with 3D gradient-echo sequences suppressing blood flow signals by radiofrequency wave spatial saturation over the scanning field of 3D time-of-flight MRA. The relative overall plaque signal intensities with reference to the sternocleidomastoid muscle were calculated, and the correlation of intensities on T1-weighted images between high-resolution BB-MRI and screening BB-MRI was investigated. We excluded 50 cases because of restenosis following CEA, use of a pacemaker, a long interval (>10 days) between high-resolution and screening BB-MRI examinations, or poor-quality images. Among the 43 cases included, the relative overall plaque signal intensity of high-resolution BB-MRI and screening BB-MRI were closely correlated (r = 0.568, p < 0.001). Screening BB-MRI can be an alternative to high-resolution BB-MRI in the assessment of IPH and may be a useful tool for detection of vulnerable plaque.

Factors Associated with Postprocedural Diffusion-Weighted Imaging-Positive Lesions in Endovascular Treatment for Unruptured Cerebral Aneurysms.

BACKGROUND: In endovascular treatment for cerebral aneurysms, the appearance of asymptomatic thromboembolic lesions detected by postprocedural diffusion-weighted imaging (DWI) can be a surrogate marker for estimating the potential risk of symptomatic thromboembolism. The aim of this study was to clarify factors associated with postprocedural DWI-positive lesions in endovascular treatment for unruptured cerebral aneurysms. METHODS: Patients with untreated unruptured cerebral aneurysms undergoing endovascular treatment were consecutively enrolled. Treatment techniques were classified into simple coiling, balloon-assisted coiling, stent-assisted coiling, and flow-diverter placement. Head magnetic resonance imaging was performed within 3 months before and 24 hours after the procedure to assess the appearance of DWI-positive lesions. RESULTS: Among 376 aneurysms in 355 patients that were analyzed, 232 (61.7%) had postprocedural DWI-positive lesions. In univariate analyses, age (P = 0.001), dome size (P < 0.001), neck size (P < 0.001), treatment technique (P = 0.029), and total procedural time (P < 0.001) were significantly associated with postprocedural DWI-positive lesions. In the multiple logistic regression model, older age (odds ratio, 1.33; 95% confidence interval, 1.10-1.60; P = 0.003; per decade), flow-diverter placement (odds ratio, 4.93; 95% confidence interval, 1.33-20.92; P = 0.016; compared with simple coiling), and longer procedural time (odds ratio, 1.66; 95% confidence interval, 1.26-2.21; P < 0.001; per hour) were associated with postprocedural DWI-positive lesions. CONCLUSIONS: Older age, flow-diverter placement, and longer procedural time were associated with postprocedural DWI-positive lesions in endovascular treatment for unruptured cerebral aneurysms.

Gene expression during the development of experimentally induced cerebral aneurysms.

Cerebral aneurysms are a major cause of subarachnoid hemorrhage, but the mechanism of their development remains unclear. In this study, we investigated candidate genes whose expression is significantly changed during the development of experimentally induced cerebral aneurysms using adaptor-tagged competitive polymerase chain reaction (ATAC-PCR). Twenty-four rats received sham operation (control) or the operation for the induction of experimental cerebral aneurysms. Rats were sacrificed at time 0, 2 weeks, 1 month and 3 months after the operation (n = 6 for each group). RNAs from right anterior cerebral artery/olfactory artery (ACA/OA) bifurcations were assessed via a 191-gene data matrix expression profile by ATAC-PCR. We identified 15 genes whose expression is significantly altered during cerebral aneurysm formation, including major heparan sulfate proteoglycan, cathepsin B, hevin and beta(4)-integrin. We also confirmed protein expression of beta(4)-integrin in rat cerebral aneurysms by quantitative real-time PCR and immunohistochemistry. The ATAC-PCR revealed temporal changes in gene expression during the development of experimental cerebral aneurysms. The genes that were significantly changed in this study would be the candidates for future studies concerning the development of cerebral aneurysms.

Evaluation of carotid artery atherosclerotic plaque distribution by using long-axis high-resolution black-blood magnetic resonance imaging.

OBJECT: The goal of this study was to evaluate the usefulness of long-axis black-blood MR (BB-MR) imaging for assessing plaque morphology and distribution in patients with atherosclerotic carotid artery (CA) stenosis. METHODS: Sixty-eight carotid arteries in 67 patients who were scheduled to undergo CA endarterectomy or CA stent placement due to atherosclerotic stenosis were included in this study. The patients had undergone CA BB-MR imaging and digital subtraction (DS) angiography within 3 weeks of revascularization. The DS angiography studies were performed using the transfemoral artery approach with selective common CA catheterization. The BB-MR images were acquired using a 1.5-T whole-body MR imaging unit, and T1-weighted images parallel to the long axis of the artery at 1-mm intervals were obtained. Plaque distribution was evaluated by measuring the distance between the CA bifurcation and the point that appeared to be the distal extent of the plaque on BB-MR imaging (D-MR imaging) and DS angiography images (D-DS angiography). RESULTS: Plaque distribution was clearly shown in 88.2% of the cases using long-axis BB-MR images, except for 8 arteries with poor image quality. In 4 arteries, D-DS angiography could not be obtained because the distal plaque end could not be confirmed. In 56 vessels, both the D-DS angiography and D-MR imaging could be measured; the mean D-MR imaging (19.75 +/- 6.85 mm [standard deviation]) was significantly longer than the average D-DS angiography (16.32 +/- 7.07 mm). CONCLUSIONS: Long-axis BB-MR imaging can provide a noninvasive and accurate way to show CA plaque distribution; it is of great use not only for stroke risk assessment in patients with CA atherosclerosis but also for preoperative evaluation in patients requiring CA endarterectomy or CA stent placement.

Effect of intrathecal milrinone injection via lumbar catheter on delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

OBJECTIVE Delayed cerebral ischemia (DCI) is an important complication after aneurysmal subarachnoid hemorrhage (aSAH). Although intrathecal milrinone injection via lumbar catheter to prevent DCI has been previously reported to be safe and feasible, its effectiveness remains unknown. The goal of this study was to evaluate whether intrathecal milrinone injection treatment after aSAH significantly reduced the incidence of DCI. METHODS The prospectively maintained aSAH database was used to identify patients treated between January 2010 and December 2015. The cohort included 274 patients, with group assignment based on treatment with intrathecal milrinone injection or not. A propensity score model was generated for each patient group, incorporating relevant patient variables. RESULTS After propensity score matching, 99 patients treated with intrathecal milrinone injection and 99 without treatment were matched on the basis of similarities in their demographic and clinical characteristics. There were significantly fewer DCI events (4% vs 14%, p = 0.024) in patients treated with intrathecal milrinone injection compared with those treated without it. However, there were no significant differences between the 2 groups with respect to their 90-day functional outcomes (46% vs 36%, p = 0.31). The likelihood of chronic secondary hydrocephalus, meningitis, and congestive heart failure as complications of intrathecal milrinone injection therapy was also similar between the groups. CONCLUSIONS In propensity score-matched groups, the intrathecal administration of milrinone via lumbar catheter showed significant reduction of DCI following aSAH, without an associated increase in complications.

Different learning curves between stent retrieval and a direct aspiration first-pass technique for acute ischemic stroke.

OBJECTIVEThe clinical outcomes of a direct aspiration first-pass technique (ADAPT) and stent retriever (SR) have been reported to be similar in several observational studies. In this study, procedural and clinical outcomes with ADAPT and SR for the treatment of acute ischemic stroke with large artery occlusion were compared in different time periods.METHODSIn each specific time period, SR and ADAPT were used as the first-line treatment approach for acute ischemic stroke patients with large artery occlusion at the authors' institution. Baseline characteristics, procedural variables, and functional outcome at 90 days were compared between patients treated with SR and those treated with ADAPT. These 2 groups were divided into 3 sequential subgroups to assess the learning curve effects of the endovascular team and individual operators on the procedural variables of each treatment strategy.RESULTSOverall, 89 patients were treated. In the SR group, the recanalization rate was higher (84% vs 65%; p = 0.01) and the procedure time was shorter than in the ADAPT group (median 42 minutes vs 76 minutes, p = 0.04). On the subgroup analysis of the learning curve, the SR group showed more rapid improvement in procedure time than the ADAPT group (p = 0.01 for the team; p < 0.01 for individual operators).CONCLUSIONSIn this initial experience, a higher recanalization rate and shorter procedure time were achieved with SR than with ADAPT. A high recanalization rate with SR was possible with relatively less clinical experience, whereas procedure time dramatically decreased with experience. These observed effects on the learning curve might be useful when choosing the method for initial endovascular treatment of acute ischemic stroke at relatively small stroke centers.

Cerebral aneurysm progression suppressed by blockage of endothelin B receptor.

OBJECT: Cerebral aneurysm is a major cause of subarachnoid hemorrhage, but the mechanisms of its development remain unclear. Mechanical stretch has been reported to induce vascular smooth-muscle cell apoptosis via endothelin B receptors (ETBRs). The objectives of this study were to clarify the expression and localization of ETBR in cerebral aneurysms and to examine the effect of ETBR blockage on the development of experimental cerebral aneurysms. METHODS: Seventy-two rats underwent a cerebral aneurysm induction procedure and were divided into four groups according to the duration of postoperative study periods. Expression of ETBR was confirmed by reverse transcription-polymerase chain reaction and immunohistochemical analysis. The authors also studied the effect of K-8794, an oral selective antagonist of ETBR, to see whether it would influence the formation of cerebral aneurysms. Two weeks after the aneurysm induction procedure, ETBR was rarely detected in anterior cerebral artery-olfactory artery bifurcations, but it was weakly expressed in experimental cerebral aneurysms at 1 month after the procedure, and markedly expressed at 3 months. The administration of K-8794 for 1 month after the procedure significantly reduced the number of advanced aneurysms and the number of apoptotic smooth-muscle cells. CONCLUSIONS: These results suggest that ETBR might play a significant role in the progression of cerebral aneurysms and have the potential to improve prevention and treatment of cerebral aneurysms.

Short-Term Results of Carotid Endarterectomy and Stenting After the Introduction of Carotid Magnetic Resonance Imaging: A Single-Institution Retrospective Study.

OBJECTIVE: Although carotid artery stenting (CAS) has been gaining popularity as an alternative to carotid endarterectomy (CEA), perioperative stroke rate following contemporary CAS remains significantly higher than stroke rate after CEA. The purpose of this study was to assess perioperative (within 30 days) therapeutic results in patients with carotid stenosis (CS) after introduction of preoperative carotid magnetic resonance imaging plaque evaluation in a single center performing both CEA and CAS. METHODS: Based on prospectively collected data for patients with CS who were scheduled for carotid revascularization, retrospective analysis was conducted of 295 consecutive patients with CS. An intervention was selected after consideration of periprocedural risks for both CEA and CAS. Concerning risk factors for CAS, results of magnetic resonance imaging plaque evaluation were emphasized with a view toward reducing embolic complications. RESULTS: CAS was performed in 114 patients, and CEA was performed in 181 patients. Comparing baseline characteristics of the 295 patients, age, T1 signal intensity of plaque, symptomatic CS, urgent intervention, and diabetes mellitus differed significantly between CAS and CEA groups. Among patients who underwent CAS, new hyperintense lesions on diffusion-weighted imaging were confirmed in 47 patients. New hyperintense lesions on diffusion-weighted imaging were recognized in 21.4% of patients who underwent CEA (n = 39), significantly less frequent than in patients who underwent CAS. CONCLUSIONS: The overall short-term outcome of CEA and CAS is acceptable. Preoperative carotid magnetic resonance imaging evaluation of plaque might contribute to low rates of ischemic complications in CAS.