Spontaneous occlusion of ruptured microaneurysm formed on postoperative transosseous anastomosis after indirect revascularization in a patient with moyamoya disease.

A 40-year-old female with a history of ischemic moyamoya disease treated with indirect revascularization at ages 12 and 25 years presented with a sudden severe headache. Imaging studies revealed focal parenchymal hemorrhage and acute subdural hematoma, confirming a microaneurysm formed on the postoperative transosseous vascular network as the source of bleeding. Conservative management was performed, and no hemorrhage recurred during the 6-month follow-up period. Interestingly, follow-up imaging revealed spontaneous occlusion of the microaneurysm. However, due to the rarity of this presentation, the efficacy of conservative treatment remains unclear. Further research on similar cases is warranted.

Characterization of PANoptosis-related genes and the immune landscape in moyamoya disease.

Moyamoya disease (MMD) is a cerebrovascular narrowing and occlusive condition characterized by progressive stenosis of the terminal portion of the internal carotid artery and the formation of an abnormal network of dilated, fragile perforators at the base of the brain. However, the role of PANoptosis, an apoptotic mechanism associated with vascular disease, has not been elucidated in MMD. In our study, a total of 40 patients' genetic data were included, and a total of 815 MMD-related differential genes were screened, including 215 upregulated genes and 600 downregulated genes. Among them, DNAJA3, ESR1, H19, KRT18 and STK3 were five key genes. These five key genes were associated with a variety of immune cells and immune factors. Moreover, GSEA (gene set enrichment analysis) and GSVA (gene set variation analysis) showed that the different expression levels of the five key genes affected multiple signaling pathways associated with MMD. In addition, they were associated with the expression of MMD-related genes. Then, based on the five key genes, a transcription factor regulatory network was constructed. In addition, targeted therapeutic drugs against MMD-related genes were obtained by the Cmap drug prediction method: MST-312, bisacodyl, indirubin, and tropanyl-3,5-dimethylbenzoate. These results suggest that the PANoptosis-related genes may contribute to the pathogenesis of MMD through multiple mechanisms.

Molecular Biomarkers Affecting Moyamoya Disease.

Although the pathogenetic pathway of moyamoya disease (MMD) remains unknown, studies have indicated that variations in the RING finger protein RNF 213 is the strongest susceptible gene of MMD. In addition to the polymorphism of this gene, many circulating angiogenetic factors such as growth factors, vascular progenitor cells, inflammatory and immune mediators, angiogenesis related cytokines, as well as circulating proteins promoting intimal hyperplasia, excessive collateral formation, smooth muscle migration and atypical migration may also play critical roles in producing this disease. Identification of these circulating molecules biomarkers may be used for the early detection of this disease. In this chapter, how the hypothesized pathophysiology of these factors affect MMD and the interactive modulation between them are summarized.

Circulating immune cell landscape and T-cell abnormalities in patients with moyamoya disease.

BACKGROUND: Moyamoya disease (MMD) stands as a prominent cause of stroke among children and adolescents in East Asian populations. Although a growing body of evidence suggests that dysregulated inflammation and autoimmune responses might contribute to the development of MMD, a comprehensive and detailed understanding of the alterations in circulating immune cells associated with MMD remains elusive. METHODS: In this study, we employed a combination of single-cell RNA sequencing (scRNA-seq), mass cytometry and RNA-sequencing techniques to compare immune cell profiles in peripheral blood samples obtained from patients with MMD and age-matched healthy controls. RESULTS: Our investigation unveiled immune dysfunction in MMD patients, primarily characterized by perturbations in T-cell (TC) subpopulations, including a reduction in effector TCs and an increase in regulatory TCs (Tregs). Additionally, we observed diminished natural killer cells and dendritic cells alongside heightened B cells and monocytes in MMD patients. Notably, within the MMD group, there was an augmented proportion of fragile Tregs, whereas the stable Treg fraction decreased. MMD was also linked to heightened immune activation, as evidenced by elevated expression levels of HLA-DR and p-STAT3. CONCLUSIONS: Our findings offer a comprehensive view of the circulating immune cell landscape in MMD patients. Immune dysregulation in patients with MMD was characterized by alterations in T-cell populations, including a decrease in effector T-cells and an increase in regulatory T-cells (Tregs), suggest a potential role for disrupted circulating immunity in the aetiology of MMD.

White matter hyperintensities mediate the association between frailty and cognitive impairment in moyamoya disease.

OBJECTIVES: The relationship between cognitive function and frailty in moyamoya disease (MMD) remains unclear, and the underlying mechanism is poorly understood. This study aims to investigate whether white matter hyperintensities (WMHs) mediate the association between frailty and cognitive impairment in MMD. METHODS: Patients with MMD were consecutively enrolled in our study from January 2021 to May 2023. Pre-admission frailty and cognition were assessed using the Clinical Frailty Scale (CFS) and cognitive tests, respectively. Regional deep WMH (DWMH) and periventricular WMH (PWMH) volumes were calculated using the Brain Anatomical Analysis using Diffeomorphic deformation toolbox based on SPM 12 software. Multivariate logistic regression analysis was conducted to evaluate the association between frailty and cognitive function in MMD. Mediation analysis was performed to assess whether WMHs explained the association between frailty and cognition. RESULTS: A total of 85 patients with MMD were enrolled in this study. On the basis of the CFS scores, 24 patients were classified as frail, 38 as pre-frail, and 23 as robust. Significant differences were observed in learning, memory, processing speed, executive functions, and semantic memory among the three groups (p < 0.001). Frailty was independently associated with memory and executive functions (p < 0.05); even after controlling for WMH. Mediation analysis indicated that the associations of frailty with memory and executive functions were partially mediated by WMH, DWMH, and PWMH (p < 0.05). CONCLUSION: Frailty is significantly correlated with a higher risk of cognitive impairment in MMD, even after adjusting for other covariates. WMHs partially mediate the association between frailty and cognitive impairment.

Natural course of hemodynamically stable hemispheres contralateral to operated hemispheres in adult patients with ischemic moyamoya diseases.

The necessity of bilateral bypass in adult moyamoya disease (MMD) remains unclear despite its recommendation for pediatric and hemorrhagic cases. We aimed to investigate the natural course of hemodynamically stable unoperated hemispheres after bypass surgery for symptomatic and hemodynamically unstable hemispheres in adult patients with ischemic MMD. Among 288 patients, the mean age at the first operation of the unstable hemispheres was 40.8 ± 12.2 years. The mean follow-up period was 62.9 ± 46.5 months. 45 patients (15.6%) experienced stroke events in the unoperated hemisphere, consisting of hemorrhagic stroke in 8 (2.8%) and ischemic stroke in 37 (12.8%), including progressive transient ischemic attack in 25 (8.7%) and infarction in 12 (4.2%). Among them, 39 patients (13.5%) underwent bypass surgery. The annual risk of total stroke is 3.0%/patient-year, with 2.5% for ischemic stroke and 0.5% for hemorrhagic stroke. The 5- and 10-year cumulative risks of ischemic stroke were 13.4% and 18.3%, respectively, and those of hemorrhagic stroke were each 3.2%. The natural course of hemodynamically stable hemispheres contralateral to the operated ones appeared fairly good. Additional bypass surgery on the unoperated hemispheres should be considered for symptomatic and hemodynamically unstable hemispheres in adult patients with ischemic MMD during the follow-up.

[Imaging risk factors for postoperative cerebral infarction in adults with ischemic Moyamoya disease].

Objective: To investigate the imaging factors associated with postoperative cerebral infarction in adult patients aged 18 and above with ischemic Moyamoya disease. Methods: The clinical data of adult patients who underwent surgeries for ischemic Moyamoya disease in the Department of Neurosurgery at Peking University International Hospital from October 2015 to October 2020 were retrospectively analyzed. Of the 239 patients, 120 were male and 119 were female, with ages ranging from 18 to 63 (41.7±10.3) years. A total of 239 patients(290 cases) underwent direct and indirect combined revascularization (CR).Gender, age, surgical side, preoperative transient ischemic attack (TIA), presence of old cerebral infarction, and imaging features were compared between the patients with (48 cases) and without (242 cases) cerebral infarction within 1 week after surgery. Multivariate logistic binary regression model was used to analyze the imaging risk factors of postoperative cerebral infarction. Results: Cerebral infarction occurred in 48 cases(16.5%) among the 290 CR group within 1 week after surgery. The proportion of patients with TIA, old cerebral infarction, ICA stenosis, A1 segment stenosis, M1 segment stenosis, abnormal posterior cerebral artery (PCA), and unstable compensation before CR in the cerebral infarction group was higher than that in the non-cerebral infarction group (P<0.05).Preoperative TIA (OR=4.514, 95%CI: 1.920-10.611), old cerebral infarction (OR=2.856,95%CI:1.176-6.936), A1 stenosis (OR=7.027,95%CI:1.877-26.308), M1 stenosis (OR=6.968,95%CI:2.162-22.459), abnormal PCA (OR=4.114,95%CI:1.330-12.728)and unstable compensation (OR=4.488,95%CI:1.194-16.865) were risk factors for cerebral infarction after CR surgery (all P<0.05). Conclusion: Among the imaging factors, TIA, old cerebral infarction, A1 stenosis, M1 stenosis, abnormal PCA and unstable compensation were risk factors for cerebral infarction in adult patients with ischemic Moyamoya disease treated by combined revascularization.

Predictive value of the hemispheric magnetic resonance angiography score on the development of indirect pial synangiosis after combined revascularization surgery for adult moyamoya disease.

PURPOSE: It is difficult to precisely predict indirect bypass development in the context of combined bypass procedures in moyamoya disease (MMD). We aimed to investigate the predictive value of magnetic resonance angiography (MRA) signal intensity in the peripheral portion of the major cerebral arteries for indirect bypass development in adult patients with MMD. METHODS: We studied 93 hemispheres from 62 adult patients who underwent combined direct and indirect revascularization between 2005 and 2019 and genetic analysis for RNF213 p.R4810K. The signal intensity of the peripheral portion of the major intracranial arteries during preoperative MRA was graded as a hemispheric MRA score (0-3 in the middle cerebral artery and 0-2 in the anterior cerebral and posterior cerebral arteries, with a high score representing low visibility) according to each vessel's visibility. Postoperative bypass development was qualitatively evaluated using MRA, and we evaluated the correlation between preoperative factors, including the hemispheric MRA score and bypass development, using univariate and multivariate analyses. RESULTS: A good indirect bypass was observed in 70% of the hemispheres. Hemispheric MRA scores were significantly higher in hemispheres with good indirect bypass development than in those with poor indirect bypass development (median: 3 vs. 1; p < 0.0001). Multiple logistic regression analysis revealed hemispheric MRA score as an independent predictor of good indirect bypass development (odds ratio, 2.1; 95% confidence interval, 1.3-3.6; p < 0.01). The low hemispheric MRA score (< 2) and wild-type RNF213 predicted poor indirect bypass development with a specificity of 0.92. CONCLUSION: Hemispheric MRA score was a predictive factor for indirect bypass development in adult patients who underwent a combined bypass procedure for MMD. Predicting poor indirect bypass development may lead to future tailored bypass surgeries for MMD.

SDF-1/CXCR4 axis participants in the pathophysiology of adult patients with moyamoya disease.

BACKGROUND: Moyamoya disease (MMD) is characterized by an abundance of moyamoya vessels; however, the precise mechanism driving the spontaneous angiogenesis of these compensatory vessels remains unclear. Previous research has established a link between the stromal cell-derived factor-1 (SDF-1)/ CXC receptor 4 (CXCR4) axis and angiogenesis under hypoxic conditions. Nevertheless, the alterations in this axis within the cerebrospinal fluid, arachnoid membranes and vascular tissue of MMD patients have not been fully investigated. METHODS: Our study enrolled 66 adult MMD patients and 61 patients with atherosclerotic vascular disease (ACVD). We investigated the SDF-1 concentration in cerebrospinal fluid (CSF) and CXCR4 expression level on the arachnoid membranes and vascular tissue. We utilized enzyme-linked immunosorbent assay and immunohistochemistr. Additionally, we cultured and stimulated human brain microvascular endothelial cells (HBMECs) and smooth muscle cells (SMCs) under oxygen and glucose deprivation (OGD) conditions followed by reoxygenation, to examine any changes in the SDF-1/CXCR4 axis. RESULTS: The results demonstrated an elevation in the level of SDF-1 in CSF among MMD patients compared to those with ACVD. Moreover, the expression of CXCR4 in arachnoid membranes and vascular tissue showed a similar trend. Furthermore, the content of CXCR4 in HBMECs and SMCs increased with the duration of ischemia and hypoxia. However, it was observed that the expression of CXCR4 decreased at OGD/R 24h compared to OGD 24h. The temporal pattern of SDF-1 expression in HBMECs and SMCs mirrored that of CXCR4 expression. CONCLUSION: These findings indicate a critical role for the SDF-1/CXCR4 axis in the angiogenesis of moyamoya disease.

[Moyamoya disease in adults: treatment methods in modern era]. / Sovremennyi podkhod k lecheniyu angiopatii moyamoya u vzroslykh.

Moyamoya angiopathy is a chronic progressive cerebrovascular disease characterized by stenosis and occlusion of the distal segments of the internal carotid arteries and/or proximal segments of the middle and anterior cerebral arteries, with a gradual compensatory restructuring of the cerebral circulation to the system of the external carotid arteries. Today, the main treatment method for Moyamoya angiopathy is surgical revascularization of the brain. A search and analysis of publications on the treatment of adult patients with Moyamoya angiopathy was carried out in the PubMed and Medscape databases over the past 10 years. We present a case of an adult female patient with a hemorrhagic form of Moyamoya angiopathy stage IV according to J. Suzuki, who underwent staged combined revascularization of both cerebral hemispheres. Surgical revascularization included the creation of a low-flow extra-intracranial shunt combined with a combination of indirect synangiosis. The combination of direct and indirect methods of surgical revascularization enables to achieve the development of an extensive network of collaterals and fully compensate for cerebral circulatory disorders both in the early and late postoperative periods, which is confirmed by instrumental diagnostic data. Combined revascularization is the most effective modern method of treating patients with Moyamoya angiopathy due to the complementary influence of direct and indirect components of revascularization.

[Various Bypass Surgery:Preoperative Simulation for STA-MCA Bypass].

In STA-MCA bypass surgery, it is important to select the optimal recipient using preoperative simulation to avoid complications. We report a preoperative simulation for STA-MCA bypass using the Brain LAB iPLAN platform®BRAIN LAB)and the 3DCG simulation software GRID®Kompath). Here, we introduce the basics and applications of preoperative simulation for occlusive atherosclerotic lesions and present a target bypass for periventricular anastomosis and peripheral vessels of aneurysms in Moyamoya disease. By creating and visualizing 3D fusion images, the optimal donor and recipient can be selected. Determining the skin incision and extent of craniotomy according to the case is also applicable to the minimally invasive STA-MCA bypass. Preoperative simulations enable accurate pinpoint bypass surgery and prevent complications.

Development of the external carotid artery system including the middle temporal artery after direct-indirect revascularization surgery for moyamoya disease.

BACKGROUND: The aim of this study was to clarify when and from which blood vessels indirect revascularization develops after combined revascularization surgery for moyamoya disease and how the donor vessels that undergo direct revascularization change in the medium to long term. In particular, we focused on the middle temporal artery (MTA), which has not received much attention in indirect revascularization surgery for moyamoya disease until now. METHODS: We targeted 20 sides that were suitable for evaluating the diameter of the external carotid artery system involved in combined revascularization surgery among moyamoya disease patients who underwent a composite revascularization procedure utilizing a 'U'-shaped skin incision encircling the parietal branch of the superficial temporal artery (STA) at our institution from 2018 to 2023. We identified the STA parietal branch, MMA, DTA, and MTA in the TOF source MR images acquired preoperatively and three and six months after surgery; measured the long and short diameters of each blood vessel; approximated the blood vessel shape as an ellipse, and calculated its cross-sectional area. RESULTS: The cross-sectional areas of the MMA, DTA, and MTA involved in indirect revascularization significantly increased compared to presurgery three months after surgery, and this trend continued six months after surgery, but no significant change was observed between three and six months after surgery. There were no cases in which the MTA was clearly confirmed before surgery in the TOF reconstructed images, but the MTA was clearly confirmed in 55% (11/20 cases) of hemispheres three months after surgery and in 85% (17/20 cases) of hemispheres six months after surgery. The crosssectional area of the STA parietal branch, which was the donor for direct revascularization, had increased by more than 150% compared to before surgery in 55% (11/20 cases) of hemispheres three months after surgery. CONCLUSIONS: Indirect revascularization can be expected three months after combined revascularization surgery for moyamoya disease. The MTA, which has not received much attention in terms of indirect revascularization for moyamoya disease patients thus far, was found to be a useful blood flow source for indirect revascularization in combined revascularization surgery for patients with moyamoya disease. Whether or not the cross-sectional area of the superficial temporal artery used as a donor for direct revascularization increased in the medium to long term varied on a case-by-case basis.

Comparison of Changes in Retinal Vascular Parameters and Density in Patients with Moyamoya Disease: A Retrospective Study.

INTRODUCTION: This study aimed to compare retinal vascular parameters and density in patients with moyamoya disease using the optical coherence tomography angiography. METHODS: This clinical trial totally enrolls 78 eyes from 39 participants, and all these patients with moyamoya disease (N = 13) are set as experimental group and participants with health who matched with age and gender are considered as the control group (N = 26). Then all these participants receive optical coherence tomography angiography detection. Participants' general data are collected and analyzed. Skeleton density (SD) value, vessel density (VD) value, fractal dimension (FD) value, vessel diameter index (VDI) value, foveal avascular zone (FAZ) value are analyzed. RESULTS: A total of 39 participants are included in this study. The SD value in the experimental group was significantly lower than that in control group (0.175 [0.166, 0.181] vs. 0.184 [0.175, 0.188], p = 0.017). Similarly, the VD value in the experimental group was significantly lower than that in the control group (0.333 [0.320, 0.350] vs. 0.354 [0.337, 0.364], p = 0.024). Additionally, the FD value in the experimental group was significantly lower than that in the control group (2.088 [2.083, 2.094] vs. 2.096 [2.090, 2.101], p = 0.022). As for the VDI and FAZ, VDI and FAZ values in the experimental group were lower than those in the control group, there was no significant difference in VDI and FAZ values between the two groups. CONCLUSIONS: Our study, using non-invasive and rapid OCTA imaging, confirmed decreased retinal vascular parameters and density in patients with moyamoya disease.

Risk Factors for Specific Postoperative Ischemic Complications in Patients with Moyamoya Disease: A Single-Center Retrospective Study.

AIM: To evaluate and compare postoperative ischemic complications to determine the risk factors for ischemic complications following revascularization surgery for Moyamoya disease (MMD). MATERIAL AND METHODS: This single-center retrospective study included 266 procedures between 2016 and 2021. Three types of revascularization approaches including direct bypass, indirect bypass, and combined bypass were performed. To identify risk factors for postoperative ischemic complications and contralateral cerebral infarction, preoperative clinical characteristics and radiographic features were examined using multivariate and ordinal logistic regression analyses. RESULTS: Postoperative ischemic complications occurred in 103 (6.6%) procedures. Ischemic presentation (p=0.001, odds ratios [OR] 5.59, 95% confidence interval [CI] 2.05-15.23), hypertension (p=0.030, OR 2.75, 95%CI 1.11- 6.83), advanced Suzuki stage (p=0.006, OR 3.19, 95%CI 1.40-7.26), and collateral circulation (p=0.001 OR 0.17, 95%CI 0.06-0.47) were risk factors for postoperative ischemic complications. Ordinal regression analysis revealed that unilateral involvement (p=0.043, OR 2.70, 95%CI 0.09-5.31), hemorrhagic presentation (p=0.013, OR 3.45, 95%CI 0.72-6.18), surgical approach (p=0.032, OR -1.38, 95%CI -2.65, -0.12), and collateral circulation [p=0.043, OR -1 .27, 95%CI -2.51, -0.04)] were associated with the type of ischemic complications. History of hypertension (p=0.031) and contralateral computed tomography (CT) perfusion stage (p=0.045) were associated with contralateral infarction. CONCLUSION: Inability of cerebral vessels to withstand changes in blood pressure induced by revascularization-related hemodynamic instability might be associated with postoperative complications in patients with Moyamoya disease.

Brain volume measured by synthetic magnetic resonance imaging in adult moyamoya disease correlates with cerebral blood flow and brain function.

Moyamoya disease (MMD) is characterized by progressive arterial occlusion, causing chronic hemodynamic impairment, which can reduce brain volume. A novel quantitative technique, synthetic magnetic resonance imaging (SyMRI), can evaluate brain volume. This study aimed to investigate whether brain volume measured with SyMRI correlated with cerebral blood flow (CBF) and brain function in adult MMD. In this retrospective study, 18 adult patients with MMD were included. CBF was measured using iodine-123-N-isopropyl-p-iodoamphetamine single photon emission computed tomography. Cerebrovascular reactivity (CVR) to acetazolamide challenge was also evaluated. Brain function was measured using the Wechsler Adult Intelligence Scales (WAIS)-III/IV and the WAIS-R tests. Gray matter (GM), white matter, and myelin-correlated volumes were evaluated in six areas. Resting CBF was positively correlated with GM fractions in the right anterior cerebral arterial and right middle cerebral arterial (MCA) territories. CVR was positively correlated with GM fraction in the right posterior cerebral arterial (PCA) territory. Full-Scale Intelligence Quotient and Verbal Comprehension Index scores were marginally positively correlated with GM fractions in the left PCA territory. Processing Speed Index score was marginally positively correlated with GM fraction in the right MCA territory. The SyMRI-measured territorial GM fraction correlated with CBF and brain function in patients with MMD.

Effect of revascularization surgery on cerebral hemodynamics in adult moyamoya disease.

OBJECTIVE: Few studies have reported local hemodynamic changes after revascularization surgery. This study aimed to identify regional hemodynamic changes after combined revascularization surgery for moyamoya disease using single-photon emission computed tomography with N-isopropyl-p-123I-iodoamphetamine. METHODS: A total of 46 adults with moyamoya disease who underwent combined revascularization surgery from August 2009 to July 2021 at our facility were enrolled. The combined bypass procedure comprised a single direct bypass to the motor area and encephalo-duro-arterio-myo-synangiosis. The preoperative and postoperative cerebral blood flow (CBF) and cerebral vascular reserve (CVR) in the genu; precentral, central, parietal, angular, temporal, and posterior regions; splenium; hippocampus; and cerebellum were measured. To modify the examination variability, the cerebral-to-cerebellar activity ratio (CCR) was calculated by dividing the counts in the region by those in the cerebellum (CBF-CCR and CVR-CCR). RESULTS: Postoperatively, asymptomatic cerebral infarction occurred in three (6.5%) patients. The CBF-CCR and CVR-CCR improved in the precentral, parietal, and temporal regions and in the overall middle cerebral artery (MCA) territory. Sub-analysis of anterior cerebral artery (ACA) and posterior cerebral artery (PCA) territory hemodynamics revealed that patients with normal preoperative hemodynamics showed no changes in the CBF-CCR and CVR-CCR postoperatively, whereas patients with preoperative perfusion impairment exhibited improved CVR-CCR in the ACA territory (0.13-0.3, p=0.019) and CBF-CCR in the PCA territory (0.93-0.96, p=0.0039). CONCLUSION: Combined revascularization surgery with single bypass to the motor area improved hemodynamics in the primary targeted MCA territory and in the ACA and PCA territories among patients with preoperative hemodynamic impairment.

Safety of antiplatelet therapy during the perioperative period of revascularization surgery for moyamoya disease patients with ischemic onset.

For patients with moyamoya disease, antiplatelet agents are often used during the perioperative periods of revascularization surgeries to prevent ischemic events. However, antiplatelet therapy is associated with the risk of hemorrhagic complications. Further, the influence of antiplatelet therapy on perioperative ischemic or hemorrhagic complications has not been investigated. This study aimed to determine the impact of antiplatelet agents on adult moyamoya disease patients with ischemic onset during the perioperative period. From January 2016 to December 2020, 183 consecutive combined (direct and indirect) revascularization surgeries for moyamoya disease patients were performed. Among these surgeries, 96 consecutive combined revascularization surgeries for adult moyamoya disease patients with ischemic onset were analyzed and perioperative ischemic and hemorrhagic complications were reviewed. Antiplatelet agents were continued during the perioperative period including on the day of surgery and the day after the surgery. Among 96 surgeries, no hemorrhagic complications occurred postoperatively. Infarction occurred in five cases (5.2%). Among the five cases, neurological deficits persisted in two cases and improved in three. The median value of bleeding volume was 112.5 mL (interquartile range, 80.0 - 200.0). Twenty-five cases (26.0%) needed blood transfusion. The modified Rankin Scale score deteriorated in two cases due to cerebral infarction. The incidence of hemorrhagic and ischemic complications after combined revascularization surgery in patients with ischemic moyamoya disease under antiplatelet therapy was low, indicating the safety of continued antiplatelet therapy.

Nonalcoholic fatty liver disease is an independent risk factor for ischemic stroke after revascularization in patients with Moyamoya disease: a prospective cohort study.

BACKGROUND: The study aimed to investigate the association between nonalcoholic fatty liver disease (NAFLD) and ischemic stroke events after revascularization in patients with Moyamoya disease (MMD). METHODS: This study prospectively enrolled 275 MMD patients from September 2020 to December 2021. Patients with alcoholism and other liver diseases were excluded. NAFLD was confirmed by CT imaging or abdominal ultrasonography. Stroke events and modified Rankin Scale (mRS) scores at the latest follow-up were compared between the two groups. RESULTS: A total of 275 patients were enrolled in the study, among which 65 were diagnosed with NAFLD. Univariate logistic regression analysis showed that NAFLD (P = 0.029) was related to stroke events. Multivariate logistic regression analysis showed that NAFLD is a predictor of postoperative stroke in MMD patients (OR = 27.145, 95% CI = 2.031-362.81, P = 0.013). Kaplan-Meier analysis showed that compared with MMD patients with NAFLD, patients in the control group had a longer stroke-free time (P = 0.004). Univariate Cox analysis showed that NAFLD (P = 0.016) was associated with ischemic stroke during follow-up in patients with MMD. Multivariate Cox analysis showed that NAFLD was an independent risk factor for stroke in patients with MMD (HR = 10.815, 95% CI = 1.259-92.881, P = 0.030). Furthermore, fewer patients in the NAFLD group had good neurologic status (mRS score ≤ 2) than the control group (P = 0.005). CONCLUSION: NAFLD was an independent risk factor for stroke in patients with MMD after revascularization and worse neurological function outcomes.

Ultrasonography monitoring with Superb Microvascular Imaging during cerebrovascular surgery.

INTRODUCTION: Ultrasonography (US) is used as a real-time dynamic imaging modality during neurosurgery. A novel Doppler US technique, Superb Microvascular Imaging (SMI), can be used to visualize low-velocity flow of small vessels at high resolution with high frame rates. We visualized vessel flow using this US SMI technique and contrast agent during cerebrovascular surgery. METHODS: Forty-three patients with an unruptured cerebral aneurysm (control), ischemic and hemorrhagic moyamoya disease, carotid artery stenosis, hemangioblastoma, severe stenosis of the middle cerebral artery, venous angioma, and intracerebral hemorrhage (ICH) underwent neurosurgery with US SMI monitoring using a contrast agent. The diameter, length, and number of penetrating vessels were analyzed in patients with an unruptured cerebral aneurysm (control), moyamoya disease, and ICH. RESULTS: Diameter and length of cerebral penetrating vessels were significantly increased in patients with moyamoya disease and ICH compared to control patients. The number of penetrating vessels was increased in moyamoya disease patients compared to control and ICH patients. In hemorrhagic moyamoya disease, flow in the penetrating vessels originated from a deep periventricular point and extended to the cerebral surface. Pulsatile cerebral aneurysms during clipping surgery and carotid artery stenosis during carotid endarterectomy were easily identified by SMI. Drastically increased vessel flow in patients with a hemangioblastoma or a venous angioma was observed. CONCLUSION: Using the US SMI technique and contrast agent, we obtained useful flow information of the vascular disease structure and intracerebral deep small vessels during cerebrovascular surgery. Further quantitative analysis will be informative and helpful for cerebrovascular surgery.