Factors related to vessel displacement due to stent retriever retraction: An in vitro study.

BACKGROUND: Thrombectomy with a stent retriever (SR) may lead to intracranial hemorrhage due to vessel displacement. We aimed to explore factors related to vessel displacement using an in vitro vessel model. METHODS: A vessel model mimicking two-dimensional left internal carotid angiography findings was used in this study. Six SR types (Solitaire 3 × 40, 4 × 40, and 6 × 40; Embotrap 5 × 37; Trevo 4 × 41; and Tron 4 × 40) were fully deployed in the M2 ascending, M2 bend, or M1 horizontal portion. Subsequently, the SR was retracted, and the vessel displacement, maximum SR retraction force, and angle of the M2 bend portion were measured. A total of 180 SR retraction experiments were conducted using 6 SR types at 3 deployment positions with 10 repetitions each. RESULTS: The mean maximum distance of vessel displacement for Embotrap Ⅲ 5 × 37 (6.4 ± 3.5 mm, n = 30) was significantly longer than that for the other five SR types (p = 0.029 for Solitaire 6 × 40 and p < 0.001 for the others, respectively). Vessel displacement was significantly longer in the M2 ascending portion group (5.4 ± 3.0 mm, n = 60) than in the M2 bend portion group (3.3 ± 1.6 mm, n = 60) (p < 0.001) and it was significantly longer in the M2 bend portion group than in the M1 horizontal portion group (1.1 ± 0.7 mm, n = 60) (p < 0.001). A positive correlation existed between the mean maximum SR retraction force or mean angle of the M2 bend portion due to SR retraction (i.e., vessel straightening) and the mean maximum distance of vessel displacement (r = 0.90, p < 0.001; r = 0.90, p < 0.001, respectively). CONCLUSIONS: Vessel displacement varied with the SR type, size, and deployment position. Moreover, vessel displacement correlated with the SR retraction force or vessel straightening of the M2 bend portion.

Microcatheter movement in the aneurysm due to low-profile visualized intraluminal support deployment: An in vitro study.

BACKGROUND: When a microcatheter is in the aneurysm, it may move due to low-profile visualized intraluminal support (LVIS) deployment. This study was designed to determine this mechanism. METHODS: Six silicon aneurysm models were created by combining the aneurysm location (side wall or bifurcation) and the parent vessel configuration (straight, ipsilateral bending, or contralateral bending). After adjusting the microcatheter tip position in the aneurysm by pushing or pulling, an LVIS stent was deployed to cover the aneurysm neck, and the changes in the microcatheter tip position was measured. Pushing and pulling were performed 15 times each for each model, for a total of 180 experiments. RESULTS: In all experiments, the microcatheter tip moved with LVIS deployment. The total movement distance was 3.00±1.59 mm, which was significantly different between the push and pull groups (p = 0.049), between the three side-wall aneurysm models (p<0.0001), and between the three bifurcation aneurysm models (p<0.0001). Backward movement in the aneurysm occurred in 21% (37/180). The frequency of backward movement was significantly different between the side-wall and bifurcation aneurysm models (p = 0.0265) and between the push and pull groups (p<0.0001). The forward movement distance was significantly different between the side-wall (n = 78) and bifurcation (n = 65) aneurysm models (p<0.0001). CONCLUSIONS: The aneurysm location, the parent vessel configuration, and adjustment of the microcatheter tip position by pushing or pulling may affect the total movement distance and forward/backward movement of the microcatheter tip due to LVIS deployment.

Factors related to microcatheter passage through the trans-cell approach using a low-profile visualized intraluminal support device: an in-vitro study.

BACKGROUND AND PURPOSE: The trans-cell approach using a low-profile visualized intraluminal support (LVIS) device is sometimes used for aneurysm coil embolization. However, factors related to microcatheter passage remain uninvestigated. We aimed to examine in-vitro factors related to microcatheter passage using the trans-cell approach with an LVIS. METHODS: Silicone vessel models (inner diameter, 4 mm) were created with different bend segments and a 4-mm hole assuming an aneurysm neck on the side of the greater curvature. The LVIS Blue (4.5 × 32 mm) was deployed at the bend segment, and passability on the trans-cell surface was evaluated by passing the microcatheter along the micro guidewire. A total of 800 passage experiments were performed using two types of microcatheter, ten types of silicone vessel, four cell widths, five cells with the same LVIS device, and two micro guidewire directions in the aneurysm. RESULTS: The Headway Duo microcatheter (35.5%, 142/400) tended to have better passability compared with the Headway 17 microcatheter (29.3%, 117/400) (p = 0.070). As the cell width and angle between the trans-cell surface and microcatheter direction increased, passability significantly increased (p = 0.027 and p < 0.001, respectively). There was no significant difference in passability when the micro guidewire was directed to the proximal side versus the distal side (p = 0.45). CONCLUSIONS: A large cell width and an obtuse angle between the trans-cell surface and microcatheter direction facilitated good passability. Although statistically marginal, microcatheters with small ledges and small tips had relatively good passability.

Impact of subcallosal artery origin and A1 asymmetry on surgical outcomes of anterior communicating artery aneurysms.

BACKGROUND: Surgical clipping of anterior communicating artery (ACoA) aneurysms remains challenging due to their complex anatomy. Anatomical risk factors for ACoA aneurysm surgery require further elucidation. The aim of this study is to investigate whether proximity of the midline perforating artery, subcallosal artery (SubCA), and associated anomaly of the ACoA complex affect functional outcomes of ACoA aneurysm surgery. METHODS: A total of 92 patients with both unruptured and ruptured ACoA aneurysms, who underwent surgical clipping, were retrospectively analyzed from a multicenter, observational cohort database. Association of ACoA anatomy with SubCA origin at the aneurysmal neck under microsurgical observation was analyzed in the interhemispheric approach subgroup (n = 56). Then, we evaluated whether anatomical factors associated with SubCA neck origin affected surgical outcomes in the entire cohort (both interhemispheric and pterional approaches, n = 92). RESULTS: In the interhemispheric approach cohort, combination of A1 asymmetry and aneurysmal size ≥ 5.0 mm was stratified to have the highest probability of the SubCA neck origin by a decision tree analysis. Then, among the entire cohort using either interhemispheric or pterional approach, combination of A1 asymmetry and aneurysmal size ≥ 5.0 mm was significantly associated with poor functional outcomes by multivariable logistic regression analysis (OR 6.76; 95% CI 1.19-38.5; p = 0.03) as compared with A1 symmetry group in the acute subarachnoid hemorrhage settings. CONCLUSION: Combination of A1 asymmetry and larger aneurysmal size was significantly associated with SubCA aneurysmal neck origin and poor functional outcomes in ACoA aneurysm surgery. Interhemispheric approach may be proposed to provide a wider and unobstructed view of SubCA for ACoA aneurysms with this high-risk anatomical variant.

Cilostazol Addition to Aspirin could not Reduce the Neurological Deterioration in TOAST Subtypes: ADS Post-Hoc Analysis.

BACKGROUND: Our previous trial acute dual study (ADS) reported that dual antiplatelet therapy (DAPT) using cilostazol and aspirin did not reduce the rate of short-term neurological worsening in non-cardioembolic stroke patients. Present post-hoc analysis investigated whether the impact of combined cilostazol and aspirin differed among stroke subtypes and factors associated with neurological deterioration and/or stroke recurrence. METHODS: Using the ADS registry, the rate of neurological deterioration, defined as clinical worsening and/or recurrent stroke, including transient ischemic attack was calculated. Stroke subtypes included large-artery atherosclerosis (LAA), small vessel occlusion (SVO), other determined etiology (Others), and undetermined etiology of stroke (Undetermined). RESULTS: Data of 1022 patients were analyzed. Deterioration was seen in 104 (10%) patients, and the rates were not markedly different between patients treated with DAPT vs. aspirin in any stroke subtypes: LAA, 19% vs. 11%, (p=0.192); SVO, 10% vs. 10% (p=1.000); Others, 6% vs. 6% (p=1.000); Undetermined, 11% vs. 8% (p=0.590). Diabetes mellitus was the independent factor associated with deterioration (odds ratio 4.360, 95% confidence interval 1.139-16.691, p=0.032) in the LAA group. Age (1.030 [1.004-1.057], p=0.026), systolic blood pressure (1.012 [1.003-1.022], p=0.010), and infarct size (2.550 [1.488-4.371], p=0.001) were associated with deterioration in SVO group, and intracranial stenosis/occlusion was associated with it in the Undetermined group (3.744 [1.138-12.318], p=0.030). CONCLUSIONS: Combined cilostazol and aspirin did not reduce the rate of short-term neurological deterioration in any clinical stroke subtype. The characteristics of patients whose condition deteriorates in the acute period may differ based on the stroke subtypes.

The Use of the Carotid Sheath as a Rotation Anchor to Detect an Anomalous Ascending Pharyngeal Artery in Carotid Endarterectomy.

Carotid endarterectomy (CEA) requires complete control of the blood backflow. An anomalous ascending pharyngeal artery (AphA) has been reported to result in incomplete control of the blood flow during CEA. Here, we present a case of symptomatic right internal carotid stenosis for which CEA was performed. An anomalous AphA was confirmed based on its origin from the distal internal carotid artery (ICA) on 3-dimensional rotational angiography (3DRA). The anomalous AphA arose near the distal end of the plaque, and the origin of the AphA was located in the dorsal wall of the ICA, hidden from the surgical view. The origin of the AphA was detected with rotation of the ICA within the carotid sheath (CS). Intraoperatively, the blood flow from the AphA was completely controlled with clamping of the origin of the AphA. We emphasize the importance of the 3DRA to detect an anomalous AphA and propose the use of the CS as an anchor to rotate the ICA for optimizing the surgical view behind the ICA. This simple surgical technique facilitates to detect and clamp an anomalous AphA arising from the ICA.

Flexible endoscopically assisted evacuation of acute and subacute subdural hematoma through a small craniotomy: preliminary results.

BACKGROUND: The first choice to treat acute subdural hematoma (SDH) is a large craniotomy under general anesthesia. However, increasing age or comorbid burden of the patients may render invasive treatment strategy inappropriate. These medically frail patients with SDH may benefit from a combination of small craniotomy and endoscopic hematoma removal, which is less invasive and even available under local anesthesia. Although hematoma evacuation with a rigid endoscope for acute or subacute SDHs has been reported in the literature, use of a flexible endoscope may have distinct advantages. In this article, we attempted to clarify the utility of small craniotomy evacuation with a flexible endoscope for acute and subacute SDH in the elderly patients. METHOD: Between November 2013 and September 2016, a total of 17 patients with acute SDH (15 patients), subacute SDH (1 patient), or acute aggravation of chronic SDH (1 patient) underwent hematoma evacuation with a flexible endoscope at our hospital and were enrolled in this retrospective study. Either under local or general anesthesia, the SDH was removed with a flexible suction tube with the aid of the flexible endoscope through the small craniotomy (3 × 4 cm). Hematoma evacuation rate, improvement of clinical symptoms, and procedure-related complications were evaluated. RESULTS: Hematoma evacuation rate was satisfactory, and statistically significant clinical improvement was observed in postoperative Glasgow Coma Scale in all cases compared to the preoperative assessment. No procedure-related hemorrhagic complications were observed. CONCLUSIONS: The results reported here suggest that small craniotomy evacuation with a flexible endoscope is a safe, effective, and minimally invasive treatment for acute and subacute SDH in selected cases.

Asymptomatic Carotid T1-High-Intense Plaque as a Risk Factor for a Subsequent Cerebrovascular Ischemic Event.

BACKGROUND: Intraplaque hemorrhage, detected as a high-signal intensity on carotid MRI, is also strongly associated with ischemic events in symptomatic patients. However, in asymptomatic patients, the relationship of the T1-high intense plaque and the subsequent stroke is not clear. The aim of this study is to test the hypothesis that asymptomatic carotid T1-high intense plaque is a risk factor for a subsequent cerebrovascular ischemic event. METHODS: Of the 1,353 consecutive patients, who underwent head and carotid MRI as part of their annual medical check-up, the imaging quality of 13 was poor and 150 did not present for follow-up examination, thus leaving 1,190 subjects for evaluation. Of the 1,190 patients, 96 patients had findings of high-signal intensity on carotid MRI and 1,094 patients did not. Cerebrovascular events were retrospectively evaluated. RESULTS: During a mean follow-up period of 53 months, 4 patients with high-signal intensities on carotid MRI (4%) and 3 with no findings (0.3%) had a cerebrovascular ischemic event, with the occurrences significantly higher in the high-signal-intensity group. (p < 0.01) Cox regression analysis indicated that the presence of the high-intense plaque on carotid MRI (hazard ratio [HR] 4.2; 95% CI 1.0-17.1; p = 0.04), age (HR 1.1; 95% CI 1.0-1.2; p = 0.003), and diabetes mellitus (HR 7.2; 95% CI 1.8-27.4; p = 0.004) were associated with the occurrence of subsequent ischemic cerebrovascular events. CONCLUSIONS: Asymptomatic carotid T1-high-intense plaque might be a potential high-risk factor for a subsequent cerebrovascular ischemic event.

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.

Histological Examination of Trousseau Syndrome-Related Thrombus Retrieved Through Acute Endovascular Thrombectomy: Report of 2 Cases.

The mechanism of thrombus formation in Trousseau syndrome remains unclear. The purpose of this study was to investigate specific pathological findings of the thrombi in Trousseau syndrome. The authors report on 2 cases of thrombi in Trousseau syndrome from large cerebral vessels removed by endovascular therapy and compared with thrombi in atherosclerosis or cardiac embolism. The first patient, a 67-year-old man, was transferred to our hospital for sudden onset consciousness disturbance and tetraparesis. He had been diagnosed with stage IV lung cancer. The magnetic resonance (MR) angiography demonstrated basilar artery occlusion. An endovascular thrombectomy was performed. The second patient, an 84-year-old woman, was transferred to our hospital for sudden onset motor aphasia and right-sided motor weakness. She has a history of stage IV pancreatic body cancer. The MR angiography demonstrated left middle cerebral artery occlusion. An endovascular thrombectomy was performed for the floating thrombus. Macroscopic findings of retrieved thrombi were observed immediately after thrombectomy. The thrombi in Trousseau syndrome were white in color and solid against manual compression, whereas thrombi from other causes were red and fragile. In terms of microscopic findings, the thrombi in Trousseau syndrome mainly contained fibrin. On the other hand, thrombi associated with atherosclerosis or cardiac embolism had smaller area of fibrin with a considerable amount of red and white blood cells. The thrombi in Trousseau syndrome, which caused occlusion of large cerebral vessel, almost exclusively consisted of fibrin.

[Indocyanine Green Videoangiography-Guided Target Bypass for Surgical Trapping of Distal Middle Cerebral Artery Aneurysm:A Technical Case Report].

Intraoperative indocyanine green(ICG)videoangiography is simple, less invasive, and enables real-time observation of hemodynamics during neurovascular surgery. In this article, we describe a case of ruptured distal middle cerebral artery aneurysm, which was unclippable and required parent artery occlusion with extracranial-intracranial bypass. Under temporary clipping of the proximal vessel, ICG videoangiography demonstrated the proper target vessel for bypass through delayed and retrograde filling of the dye. In this operation, ICG videoangiography contributed to simpler and less invasive procedures, by avoiding dissection of the tight cerebral fissure and intraoperative angiography.

Reflux of Anterior Spinal Artery Predicts Recurrent Posterior Circulation Stroke in Bilateral Vertebral Artery Disease.

BACKGROUNDS AND PURPOSE: Predictive value of reflux of anterior spinal artery for recurrent posterior circulation ischemia in bilateral vertebral arteries steno-occlusive disease was evaluated. METHODS: We retrospectively reviewed 55 patients with symptomatic posterior circulation stroke caused by bilateral stenotic (>70%) lesions of the vertebral artery. We investigated any correlation of clinical and angiographic characteristics including collateral flow patterns, with recurrent stroke. Risk factors for poor 3-month functional outcome were also evaluated. RESULTS: Recurrent posterior circulation stroke was observed in 15 (27.3%) patients. Multivariable analysis using Cox proportional hazards model showed anterior spinal artery reflux as a significant risk factor for stroke recurrence (adjusted hazard ratio, 19.3 [95% confidence interval, 5.35-69.9]; P<0.001). Anterior spinal artery reflux was also correlated with poor functional outcome (modified Rankin Scale score, 3-6; adjusted odds ratio, 7.41 [95% confidence interval, 1.24-44.4]; P=0.028). CONCLUSIONS: In patients with symptomatic bilateral vertebral artery occlusive disease, anterior spinal artery reflux predicted recurrent posterior circulation stroke and poor functional outcome.

[De novo distal superior cerebellar artery aneurysm after embolization of a ruptured aneurysm at the bifurcation of the contralateral basilar and superior cerebellar arteries].

The formation of de novo aneurysms in the posterior fossa after successful treatment of a previous aneurysm in the same fossa is rare. Here we describe a case of a de novo generated aneurysm at the distal superior cerebellar artery(SCA)7 years after the successful obliteration of an aneurysm at the contralateral basilar artery(BA)-SCA bifurcation. The treatment of the original posterior fossa aneurysm may lead to hemodynamic changes that may contribute to the formation of a de novo aneurysm at another vulnerable point in the posterior fossa circulation. We conclude that a close surveillance is required after the initial treatment of posterior fossa aneurysms in order to detect the possible formation of de novo aneurysms.

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.

Learning Curve Effect of Combined Technique Thrombectomy as First-Line Attempt for Acute Ischemic Stroke: A Single-Center Retrospective Study.

OBJECTIVES: We retrospectively examined the initial experience and learning curve after the introduction of thrombectomy with the combined technique using an aspiration catheter and a stent retriever as first-line attempt for acute ischemic stroke. METHODS: Consecutive patients undergoing thrombectomy for acute ischemic stroke at our institution between January 2020 and December 2022 were divided into 3 groups according to the year of thrombectomy. Patient characteristics and procedural, safety, and clinical outcomes were compared between the three year periods to determine predictors of favorable clinical outcome. RESULTS: In 2020, 2021, and 2022, the numbers of patients were 74, 70, and 90, respectively, with similar patient characteristics across the three years; successful recanalization rates were 79.7%, 97.1%, and 93.3%, respectively (P < 0.01 for the first 2 years); median procedure times were 67, 43, and 32 minutes, respectively (P < 0.01 for the first 2 years and P = 0.018 for the last 2 years); first pass effect rates were 20.3%, 41.4%, and 44.4%, respectively (P < 0.01 for the first 2 years); symptomatic intracranial hemorrhage rates were 14.9%, 2.9%, and 1.1%, respectively (P = 0.018 for the first 2 years); and percentages of modified Rankin Scale score 0-2 at 90 days were 24.3%, 42.9%, and 41.1%, respectively (P = 0.022 for the first 2 years). Procedure time (P = 0.038) and successful recanalization (P = 0.041) were independent predictors of favorable clinical outcome. CONCLUSIONS: The learning curve effect of the combined technique may be associated with better clinical outcome due to increased successful recanalization rates, shortened procedure time, and reduced symptomatic intracranial hemorrhage.

Stroke incidence and usage rate of thrombolysis in a Japanese urban city: the Kurashiki stroke registry.

BACKGROUND: To investigate stroke incidence and rate of thrombolytic therapy in an urban city of around 500,000 residents. METHODS: Patients suffering acute stroke in Kurashiki City (population 474,415) between March 2009 and February 2010 (inclusive) and admitted to 1 of 10 hospitals throughout the city were prospectively enrolled. RESULTS: We enrolled patients with first-ever stroke (n = 763; men 415; median age 72 years) and first-ever/recurrent stroke (n = 1009; men 552; median age 73 years). Among first-ever strokes, 68% were cerebral infarctions, 23% were intracerebral hemorrhages, and 8% were subarachnoid hemorrhages. Crude incidences for first-ever stroke per 100,000 residents were 159.8 (95% confidence interval [CI] 148.4-171.1) for all strokes, 108.8 (95% CI 99.4-118.1) for cerebral infarction, and 36.5 (95% CI 31.0-41.9) for intracerebral hemorrhage. After adjustment using the world population model, age-adjusted incidences were 60.7 (95% CI 45.4-75.9) for all strokes, 38.4 (95% CI 26.3-50.5) for cerebral infarction, and 16.1 (95% CI 8.3-24.0) for intracerebral hemorrhage. Among 698 cases with first-ever and recurrent cerebral infarction, thrombolysis was administered for 31 (5%). Of 197 cerebral infarction patients admitted within 3 hours of onset, the thrombolysis rate was 16%. CONCLUSION: In this urban Japanese city, the age-adjusted incidence of first-ever stroke between March 2009 and February 2010 was 60.7 per 100,000 residents, which was relatively low compared with findings for other countries. Thrombolysis was given to approximately 5% of patients with acute ischemic stroke.

[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.

Factors related to white thrombi in acute ischemic stroke in cancer patients.

OBJECTIVES: Thrombi in cerebral large vessel occlusion associated with active cancer are often fibrin and platelet-rich white thrombi. However, evaluating the thrombus composition in a short time before thrombectomy is often ineffective. We sought to determine factors related to white thrombi in acute ischemic stroke due to large vessel occlusion in cancer patients. METHODS: Consecutive cancer patients undergoing thrombectomy for acute ischemic stroke due to large vessel occlusion between January 2018 and May 2022 were retrospectively reviewed. The patients were classified into white thrombus and red thrombus groups on the basis of the pathological findings of retrieved thrombi. Patient characteristics and laboratory findings were compared between the two groups. RESULTS: There were 12 patients in the white thrombus group and 11 patients in the red thrombus group. Active cancer was significantly more in the white thrombus group than in the red thrombus group (91.7% vs. 36.3%, p = 0.0094). Internal carotid artery occlusion was significantly less in the white thrombus group than in the red thrombus group (0% vs. 36.4%, p = 0.037). Among laboratory findings, D-dimer levels were an independent factor associated with white thrombi (odds ratio 8.97 [95% confidence interval 1.71-368.99], p < 0.0001). The cutoff value of D-dimer levels for predicting white thrombi was 3.5 µg/mL (83.3% sensitivity and 100% specificity). CONCLUSIONS: In acute ischemic stroke in cancer patients, active cancer, no internal carotid artery occlusion, and higher D-dimer levels (≥3.5 µg/mL) may be associated with occlusion with fibrin and platelet-rich white thrombi.

Correlation of Scoring Systems with the Requirement of an External Ventricular Drain in Intraventricular Hemorrhage.

BACKGROUND: External ventricular drainage (EVD) is required to resolve acute hydrocephalus associated with intraventricular hemorrhage (IVH). The correlation of scoring systems of IVH with indications for EVD for acute hydrocephalus related to IVH is currently unknown. METHODS: We identified 213 hypertensive patients with IVH and divided them into 2 groups according to treatment method: 187 patients receiving blood pressure control alone and 26 patients undergoing EVD. The following patients were excluded: pediatric patients, patients undergoing intracranial hematoma removal, patients with fetal status, and patients without sufficient clinical data. We compared the Glasgow Coma Scale score, Graeb score, LeRoux score, Evans index, and bicaudate index values between the 2 groups and determined the prognostication accuracy of each scoring system. RESULTS: There were significant differences in all 4 scoring systems between the 2 groups (P < 0.001). The cutoff values (sensitivity and specificity) of each scoring system were as follows: Glasgow Coma Scale, 8 (65.4%, 87.7%); Graeb score, 6 (80.8%, 75.4%); LeRoux score, 9 (80.8%, 76.5%); Evans index, 0.245 (80.8%, 67.9%); and bicaudate index, 0.186 (76.9%, 76.5%). The value of the area under the curve of each scoring system (95% confidence interval) was as follows: Glasgow Coma Scale, 0.806 (0.705-0.907); Graeb score, 0.852 (0.779-0.925); LeRoux score, 0.875 (0.812-0.937); Evans index, 0.788 (0.702-0.875); and bicaudate index, 0.778 (0.673-0.883). CONCLUSIONS: The LeRoux score is better for identifying patients with IVH who are more likely to have EVD.

Rescue therapy for vasospasm following aneurysmal subarachnoid hemorrhage: a propensity score-matched analysis with machine learning.

OBJECTIVE: Rescue therapies have been recommended for patients with angiographic vasospasm (aVSP) and delayed cerebral ischemia (DCI) following subarachnoid hemorrhage (SAH). However, there is little evidence from randomized clinical trials that these therapies are safe and effective. The primary aim of this study was to apply game theory-based methods in explainable machine learning (ML) and propensity score matching to determine if rescue therapy was associated with better 3-month outcomes following post-SAH aVSP and DCI. The authors also sought to use these explainable ML methods to identify patient populations that were more likely to receive rescue therapy and factors associated with better outcomes after rescue therapy. METHODS: Data for patients with aVSP or DCI after SAH were obtained from 8 clinical trials and 1 observational study in the Subarachnoid Hemorrhage International Trialists repository. Gradient boosting ML models were constructed for each patient to predict the probability of receiving rescue therapy and the 3-month Glasgow Outcome Scale (GOS) score. Favorable outcome was defined as a 3-month GOS score of 4 or 5. Shapley Additive Explanation (SHAP) values were calculated for each patient-derived model to quantify feature importance and interaction effects. Variables with high SHAP importance in predicting rescue therapy administration were used in a propensity score-matched analysis of rescue therapy and 3-month GOS scores. RESULTS: The authors identified 1532 patients with aVSP or DCI. Predictive, explainable ML models revealed that aneurysm characteristics and neurological complications, but not admission neurological scores, carried the highest relative importance rankings in predicting whether rescue therapy was administered. Younger age and absence of cerebral ischemia/infarction were invariably linked to better rescue outcomes, whereas the other important predictors of outcome varied by rescue type (interventional or noninterventional). In a propensity score-matched analysis guided by SHAP-based variable selection, rescue therapy was associated with higher odds of 3-month GOS scores of 4-5 (OR 1.63, 95% CI 1.22-2.17). CONCLUSIONS: Rescue therapy may increase the odds of good outcome in patients with aVSP or DCI after SAH. Given the strong association between cerebral ischemia/infarction and poor outcome, trials focusing on preventative or therapeutic interventions in these patients may be most able to demonstrate improvements in clinical outcomes. Insights developed from these models may be helpful for improving patient selection and trial design.