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Background: Long-term outcomes are unknown in patients with asymptomatic moyamoya disease. In this report, we aimed to clarify their 5-year risk of stroke and its predictors. Methods: We are conducting a multicenter, prospective cohort study (Asymptomatic Moyamoya Registry) in Japan. Participants were eligible if they were 20 to 70 years, had bilateral or unilateral moyamoya disease, experienced no episodes suggestive of TIA and stroke; and were functionally independent (modified Rankin Scale score 0–1). Demographic and radiological information was collected at enrollment. In this study, they are still followed up for 10 years. In this interim analysis, we defined the primary end point as a stroke occurring during a 5-year follow-up period. Independent predictors for stroke were also determined, using a stratification analysis method. Results: Between 2012 and 2015, we enrolled 109 patients, of whom 103 patients with 182 involved hemispheres completed the 5-year follow-up. According to the findings on DSA and MRA, 143 hemispheres were judged as moyamoya disease and 39 hemispheres as questionable manifestations (isolated middle cerebral artery stenosis). The patients with questionable hemispheres were significantly older, more often male, and more frequently had hypertension than those with moyamoya hemisphere. Moyamoya hemispheres developed 7 strokes, including 6 hemorrhagic and 1 ischemic stroke, during the first 5 years. The annual risk of stroke was 1.4% per person, 0.8% per hemisphere, and 1.0% per moyamoya hemisphere. Independent predictor for stroke was Grade-2 choroidal anastomosis (hazard ratio, 5.05 [95% CI, 1.24–20.6]; P =0.023). Furthermore, microbleeds (hazard ratio, 4.89 [95% CI, 1.13-21.3]; P =0.0342) and Grade-2 choroidal anastomosis (hazard ratio, 7.05 [95% CI, 1.62–30.7]; P =0.0093) significantly predicted hemorrhagic stroke. No questionable hemispheres developed any stroke. Conclusions: The hemispheres with asymptomatic moyamoya disease may carry a 1.0% annual risk of stroke during the first 5 years, the majority of which are hemorrhagic stroke. Grade-2 choroidal anastomosis may predict stroke, and the microbleeds and Grade-2 choroidal anastomosis may carry the risk for hemorrhagic stroke. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: UMIN000006640.

OBJECTIVE Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive stenosis of the internal carotid artery (ICA) and secondary formation of collateral vessels. Revascularization surgery is performed in patients with MMD to prevent stroke; however, the pathogenesis of MMD remains unknown. Recently, long noncoding RNAs (lncRNAs) have been found to play a key role in gene regulation and are implicated in various vascular diseases. However, the lncRNA expression profile in MMD lesions has not been investigated. In this study the authors aimed to determine the characteristics of lncRNA expression in MMD lesions. METHODS The authors collected microsamples of the middle cerebral artery (MCA) from patients with MMD (n = 21) and patients with control conditions (n = 11) who underwent neurosurgical treatment. Using microarray experiments, the authors compared the profiles of lncRNA expression in the MCAs of the MMD and control patient groups and identified differentially expressed lncRNAs (fold change > 2, q < 0.05). In addition, the neighboring coding genes, whose transcription can be regulated in cis by the identified differentially expressed lncRNAs, were investigated and Gene Ontology (GO) analysis was applied to predict associated biological functions. RESULTS The authors detected 308 differentially expressed lncRNAs (fold change > 2, q < 0.05), including 306 upregulated and 2 downregulated lncRNAs in the MCA from patients with MMD. Regarding the prediction of biological function, GO analyses with possible coding genes whose transcription was regulated in cis by the identified differentially expressed lncRNAs suggested involvement in the antibacterial humoral response, T-cell receptor signaling pathway, positive regulation of cytokine production, and branching involved in blood vessel morphogenesis. CONCLUSIONS The profile of lncRNA expression in MMD lesions was different from that in the normal cerebral artery, and differentially expressed lncRNAs were identified. This study provides new insights into the pathophysiology of MMD.

BACKGROUND Developmental venous anomalies (DVAs) are congenital anatomical variants of the normal deep parenchymal veins. DVAs are occasionally found incidentally on brain imaging, and most cases are asymptomatic. However, they rarely cause central nervous disorders. Herein, a case of mesencephalic DVA that caused aqueduct stenosis and hydrocephalus and discuss its diagnosis and treatment is reported. OBSERVATIONS The patient was a 48-year-old female who presented with depression. Computed tomography and magnetic resonance imaging (MRI) of the head revealed obstructive hydrocephalus. Contrast-enhanced MRI revealed an abnormally distended linear region with enhancement on the top of the cerebral aqueduct, which was confirmed as a DVA by digital subtraction angiography. An endoscopic third ventriculostomy (ETV) was performed to improve the patient’s symptoms. Intraoperative endoscopic imaging showed obstruction of the cerebral aqueduct by the DVA. LESSONS This report describes a rare case of obstructive hydrocephalus caused by DVA. It highlights the usefulness of contrast-enhanced MRI for diagnosing cerebral aqueduct obstructions due to DVAs and the effectiveness of ETV as a treatment option.

Introduction Revascularization surgery for young children with moyamoya disease (MMD) is challenging. Although indirect revascularization is preferred because of the technical difficulty in direct anastomosis, higher risks of postoperative infarction remain a problem. We aimed to investigate the effect of superficial temporal artery to middle cerebral artery (STA-MCA) bypass on postoperative outcomes during the acute postoperative period in young children ≤ 5 years old with MMD. Methods This retrospective study included consecutive young children with MMD who underwent surgical revascularization of the anterior cerebral circulation. Groups were determined according to the procedures performed, namely, the combined (STA-MCA bypass with indirect revascularization) and the indirect revascularization groups. The incidences of radiological or symptomatic infarction, transient neurological events, and new neurological deficits that remained at discharge were compared between groups. Results Of 39 surgical procedures, there were 23 combined and 16 indirect revascularizations. The median age of the patients was 3.0 years, which was significantly different between groups (P P P

Cerebral revascularization for moyamoya disease (MMD) is an effective treatment for improving cerebral ischaemia and preventing rebleeding. Although direct bypass surgery is commonly performed on older children and adults, it is challenging in very young children due to the high difficulty level of the procedure. The subjects were MMD patients under 3 years of age on whom surgery was performed by a single surgeon (Y.A.). Preoperative clinical findings, information related to direct bypass surgery, bypass patency, and the incidence of postoperative stroke were investigated. Combined revascularization, including direct bypass surgery, was performed on 3 MMD patients (3 sides) under 3 years of age. The average diameter of the grafts used in direct bypass was 0.8 mm. The average recipient diameter was 0.8 ± 0.17 (range 0.6-1) mm. In all cases, the anastomotic procedure was completed using 11-0 monofilament nylon thread, and patency was confirmed. Direct bypass for MMD patients under 3 years old is technically challenging. However, despite the anatomical differences between very young children and elderly individuals, direct bypass surgery could certainly be completed. In addition, a rapid recovery from cerebral blood flow insufficiency could yield a promising neurological outcome.

Background: The aim of this study was to investigate the association between early postoperative slow flow in bypass grafts and preoperative focal cerebral blood flow (CBF) in patients who underwent combined surgery for moyamoya disease (MMD). Methods: The subjects were 18 patients (22 surgeries) who underwent single photon emission computed tomography (SPECT) before surgery. The CBF value of the middle cerebral artery territory was extracted from the SPECT data, and the value relative to the ipsilateral cerebellar CBF (relative CBF, or RCBF) was calculated. The association between RCBF and early postoperative slow flow in the bypass graft was investigated. In addition, the correlation between the revascularization effect and preoperative RCBF was analyzed. Results: In four of 22 surgeries (18.2%), slow flow in the bypass graft was identified in the early postoperative period. Preoperative RCBF in the slow flow and patent groups was 0.86 ± 0.15 and 0.87 ± 0.15, respectively, with no significant difference (P = 0.72). The signal intensity of four slow-flowed bypasses was improved in all cases on magnetic resonance angiography images captured during the chronic phase (mean of 3.3 months postoperatively). The revascularization scores were 2 ± 0.82 and 2.1 ± 0.68 in the slow flow and patent groups, respectively, and did not differ significantly (P = 0.78). A significant correlation was not observed between preoperative RCBF and the revascularization effect. Conclusion: No significant association was observed between preoperative RCBF and early postoperative slow flow in bypass grafts in patients with MMD undergoing combined surgery. Given the high rate of improved depiction of slow-flowed bypass in the chronic postoperative phase, the conceptual significance of an opportune surgical intervention is to maintain CBF by supporting the patient’s own intracranial-extracranial conversion function.

Stroke and neurological outcomes in the early phase following revascularization for moyamoya disease (MMD) may depend on the patient's age. In this study, an age-stratified comparative analysis was performed to clarify this issue. We reviewed 105 MMD patients who underwent 179 revascularization surgeries. The demographic characteristics were collected in four age groups (≤ 5 and 6-17 years for pediatric patients and 18-49 and ≥ 50 years for adults). Additionally, we assessed the incidence of subsequent stroke and deterioration of modified Rankin Scale (mRS) score. Then, we evaluated predictors of postoperative stroke and mRS deterioration using logistic regression. The mean patient age was 26.2 ± 18.5 years. No significant difference in the incidence of postoperative stroke was observed between age groups; however, the incidence tended to be increased among patients aged ≤ 5 years (17.9%) and patients aged ≥ 50 years (16.7%). Deterioration of mRS scores was significantly associated with ages ≤ 5 years (17.9%) and ≥ 50 years (11.1%). Logistic regression showed that posterior cerebral artery involvement (odds ratio [OR], 4.6) and postoperative transient neurological events (TNEs) (OR, 5.93) were risk factors for postoperative stroke. Age ≤ 5 years (OR, 9.73), postoperative TNEs (OR, 7.38), and postoperative stroke (OR, 49) were identified as predictors of unfavorable neurological outcomes. The novel feature of this comparative analysis by age group is that membership in the early-childhood MMD patient group (under 5 years old) was an independent risk factor for unfavorable short-term neurological outcomes and was mainly associated with the incidence of postoperative severe cerebral infarction.

In cases of a dural arteriovenous fistula (AVF) with a pial arterial supply, postoperative hemorrhagic complications occur frequently. Six cases in which patients were diagnosed with a coexisting dural AVF and pial arteriovenous malformation (AVM) sharing a common drainer are presented. These cases were initially thought to be dural AVFs with pial arterial supplies, but careful examination of preoperative images showed that a pial AVM coexisted near the dural AVF, and that both shared a common drainer. The coexistence of a pial AVM is difficult to notice during surgery; for this reason, determining the presence of a pial AVM on preoperative imaging is essential to safely treat a dural AVF with a pial arterial supply. The details of each case, specifically, the diagnostic evidence for this condition (coexisting dural AVF and pial AVM sharing a common drainer), as well as imaging findings that should be noted, are presented.

In superficial temporal artery to middle cerebral artery anastomosis with indirect revascularization for patients with moyamoya disease, the optimal method for selecting the most appropriate cortical artery for the recipient in anastomosis has not been established. We investigated the relationship between the fluorescence emission timing of the recipient artery in the preanastomosis indocyanine green videoangiography and operative outcomes. This retrospective study included 51 surgical revascularization procedures for 39 moyamoya disease patients. The enrolled surgical procedures were classified into three groups based on the fluorescence emission timing of the recipient artery in preanastomosis indocyanine green videoangiography: the EARLIEST, the INTERMEDIATE, and the LATEST. Clinical characteristics and operative outcomes were also collected. The occurrence of white thrombus at the anastomosis site and symptomatic hyperperfusion showed significant differences between the groups classified by the fluorescence emission timing of the recipient artery in preanastomosis indocyanine green videoangiography (white thrombus, p = 0.001; symptomatic hyperperfusion, p = 0.026). The development of white thrombi was significantly higher in the LATEST group, and all symptomatic hyperperfusion was observed in the EARLIEST group. These results indicated that the LATEST group had a significantly higher risk for developing white thrombus, and the EARLIEST group was prone to occur symptomatic hyperperfusion. Selecting the recipient artery based on evaluating the fluorescence emission timing in preanastomosis indocyanine green videoangiography may be useful in reducing perioperative complications.

Cone beam computed tomography (CBCT) images are degraded by artifacts due to endovascular implants. We evaluated the use of streak metal artifact reduction technique (SMART) in non-contrast CBCT images after endovascular neurosurgery obtained from 148 patients (125 with aneurysm and 23 with dural arteriovenous fistula [dAVF]). Three neurosurgeons evaluated the cistern and brain surface visibility in CBCT images with and without SMART correction based on a 4-point scale (1, excellent; 2, good; 3, limited; and 4, insufficient). Significant improvement in visibility was achieved when the median scores improved from 4 or 3 to 2 or 1 or from 2 to 1. Metal artifact reduction in adjacent slices without metal and new artifacts after SMART correction was also examined. A significant improvement was achieved regarding the visibility of the cistern in 90 (60.8%) images and of the brain surface in 108 (73.0%) images. Metal size (cistern: odds ratio [OR], 0.91 per 1 mm increase; 95% confidence interval [CI], 0.83–0.99), irregular metal shape (cistern: OR, 0.18; 95% CI, 0.05–0.60 and brain surface: OR, 0.15; 95% CI, 0.05–0.45), and infratentorial lesions (cistern: OR, 0.37; 95% CI, 0.14–0.96 and brain surface: OR, 0.30; 95% CI, 0.11–0.80) were negatively correlated with improved visibility. Metal artifact reduction in adjacent slices without metal was obtained in 25.6% and 34.8% of images with aneurysm and dAVF, respectively. New artifacts after SMART correction were found in 4.8% and 13.0% of images with aneurysm and dAVF, respectively. SMART is especially effective for supratentorial small aneurysms.

Cerebral revascularization surgery has been established as an effective treatment for moyamoya disease. On the other hand, harvesting grafts and tissues to nourish the scalp may increase the risk of postoperative wound-related complications. The purpose of this study was to clarify risk factors for wound-related complications after examining the relationship with the surgical design.We retrospectively analyzed 115 patients who underwent 197 revascularization procedures between October 2004 and March 2019. The design of the revascularization was classified into 6 types, then further classified according to the number of grafts harvested, resulting in 11 subtypes. Incidences of minor and major wound-related complications for the 11 different surgical designs were assessed. The risk of complications from each design was statistically examined. In addition, the yearly transition rate of complications was also investigated.Wound-related complications occurred in 38 of the 195 operations (19.5%), including 10 major events (26.3%) and 28 minor events (73.7%). Significant differences in the incidence of complications were seen according to surgical design (P0.05), with complications significantly more frequent for L(a) double type and L(p) double type and less frequent for L(a) single type and L(p) single type. In addition, significant differences were found in the incidence and degree of complications according to the number of grafts (0-2) (P0.05). The incidence of wound-related complications has clearly decreased since 2015.Wound-related complications were more frequent and tended to become more severe with double-bypass procedures but were clearly improved under a plastic surgery approach.

This study aimed to analyze whether the development of donor vessels after combined revascularization surgery for moyamoya disease (MMD) was related to cerebral blood flow (CBF) changes. We retrospectively reviewed the charts of 11 adult (12 hemispheres) and 13 pediatric (19 hemispheres) patients who underwent combined revascularization in our department. The total vessel cross-sectional area (TVA) was the sum of the cross-sectional areas of the superficial temporal, middle meningeal, and deep temporal arteries imaged using time-of-flight magnetic resonance angiography. The ipsilateral relative CBF (RCBF) on the brain surface in the craniotomy area was calculated by single-photon emission computed tomography. The preoperative and postoperative ratios of the TVA and RCBF were defined as ΔTVA and ΔRCBF, respectively. Finally, we investigated the correlation between ΔTVA and ΔRCBF in adults and children. The TVA and RCBF showed a significant increase after surgery regardless of the age group. However, there was no significant correlation between ΔTVA and ΔRCBF in either the adult or pediatric groups. The adult group had significantly higher ΔRCBF values than the pediatric group (p

BACKGROUND Symptomatic hyperperfusion after cerebral revascularization for pediatric moyamoya disease (MMD) is a rare phenomenon. The authors report a series of patients with this condition. OBSERVATIONS In all three patients in this case series, the combined revascularization was on the left side, the patency of bypass grafts was confirmed after surgery, and focal hyperemia around the anastomotic site was observed on single photon emission computed tomography (SPECT). On the first to eighth days after surgery, all of the patients developed neurological manifestations, including motor aphasia, cheiro-oral syndrome, motor weakness of their right upper limbs, and severe headaches. These symptoms disappeared completely approximately 2 weeks after surgery, and all patients were discharged from the hospital. Quantitative SPECT was performed to determine the proportional change in cerebral blood flow (ΔRCBF) (to ipsilateral cerebellar ratio (denoted ΔRCBF) in the region of interest around the anastomoses, and the mean value was 1.34 (range, 1.29–1.41). LESSONS This rare condition, which develops soon after surgery, requires an accurate diagnosis by SPECT. One indicator is that the ΔRCBF has risen to 1.3 or higher. Subsequently, strategic blood pressure treatment and fluid management could prevent the development of hemorrhagic stroke.

We examined the specific changes that occur in the expression levels of extracellular vesicle (EV)-derived microRNAs (miRNAs) in intracranial cerebrospinal fluid (CSF) in moyamoya disease. Patients with arteriosclerotic cerebral ischemia were used as controls to eliminate the effects of cerebral ischemia. Comprehensive expression analysis of miRNAs extracted from EVs by next-generation sequencing (NGS) and validation by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed. Experiments were conducted on eight cases of moyamoya disease and four control cases. In the comprehensive miRNA expression analysis, 153 miRNAs were upregulated and 98 miRNAs were downregulated in moyamoya disease compared to the control (q-value 1). qRT-PCR performed on the four most valuable miRNAs (hsa-miR-421, hsa-miR-361-5p, hsa-miR-320a, and hsa-miR-29b-3p) associated with vascular lesions among the differentially expressed miRNAs gave the same results as miRNA sequencing. In GO analysis for the target genes, cytoplasmic stress granule was the most significant GO term. This study is the first comprehensive expression analysis of EV-derived miRNAs in the CSF of moyamoya disease patients using NGS. The miRNAs identified here may be related to the etiology and pathophysiology of moyamoya disease.

OBJECTIVE The protocol for antiplatelet therapy after stent-assisted coil embolization (SACE) for intracranial aneurysms is not well established. In particular, the indications for single antiplatelet therapy (SAPT) discontinuation remain controversial. The authors investigated the long-term outcomes of SAPT discontinuation after SACE among patients at a single institution. METHODS Patients who underwent SACE during the period from 2010 to 2020 and who were followed up for > 1 year were included in this study. The delayed ischemic and hemorrhagic complication rates were examined during follow-up. Moreover, the risk factors of antiplatelet therapy reduction or discontinuation and the outcomes of SAPT discontinuation were examined. RESULTS In total, 240 patients were included in the analysis. The average patient age was 60.3 years, and the average follow-up period was 46.7 months. Nine (3.8%) patients presented with symptomatic delayed ischemic complication, and 3 (1.3%) patients experienced a decline in modified Rankin Scale score. The stent configuration (T- or Y-stent) was the only risk factor associated with delayed ischemic complication (p < 0.001). SAPT was discontinued in 147 (71.7%) of 205 patients who were followed up for > 2 years, and no ischemic complications were observed. CONCLUSIONS It is safe to discontinue SAPT in patients without ischemic complications and with stable intraaneurysmal signals on MRA 2 years after SACE. The T- or Y-stent is a high-risk factor for delayed ischemic complications, and antiplatelet therapy reduction or discontinuation should be cautiously considered.

BACKGROUND Remote cerebral infarction after combined revascularization of the middle cerebral artery (MCA) territory is rare in patients with moyamoya disease (MMD) with a fetal-type posterior communicating artery (PCoA). OBSERVATIONS A 57-year-old woman developed numbness in her right upper limb and transient motor weakness and was diagnosed with MMD. She also had a headache attack and a scintillating scotoma in the right visual field. Preoperative magnetic resonance angiography (MRA) showed stenosis of the left posterior cerebral artery (PCA). Combined revascularization was performed for the left MCA territory. No new neurological deficits were observed for 2 days after the operation, but right hemianopia, alexia, and agraphia appeared on postoperative day (POD) 4. Magnetic resonance imaging showed a new left occipitoparietal lobe infarction, and MRA showed occlusion of the distal left PCA. After that point, the alexia and agraphia gradually improved, but right hemianopia remained at the time of discharge on POD 18. LESSONS Cerebral ischemia in the PCA territory may occur after combined revascularization of the MCA territory in patients with fetal-type PCoA. For these cases, a double-barrel bypass or indirect revascularization to induce a slow conversion could be considered on its own as a treatment option.

OBJECTIVE After revascularization surgery in pediatric patients with moyamoya disease (MMD), resting and avoiding crying is important. However, this inaction is often difficult because of pain or anxiety. Dexmedetomidine (DEX), which has sedative and analgesic properties, may be useful in reducing those uncomfortable conditions; however, its common side effects include bradycardia and hypotension, which have a risk of decreasing the cerebral blood flow. The aim of this study was to investigate the efficacy and safety of using DEX for pediatric patients with MMD in the acute period after revascularization surgery. METHODS This retrospective study included pediatric patients with MMD who underwent revascularization surgery. Based on whether DEX was used for light sedation during postoperative days (PODs) 0–1 after extubation, the patients were divided into DEX or control groups. For neurological outcomes, the incidence of symptomatic cerebral infarction and transient neurological events (TNEs) during PODs 0–1 and the entire hospitalization were investigated. In addition, the Richmond Agitation-Sedation Scale (RASS) was used to assess the effect of DEX, and bradycardia and hypotension were evaluated as side effects. RESULTS A total of 84 surgical procedures were included in this study (27 in the DEX group and 57 in the control group). During PODs 0–1, symptomatic infarction was not observed in either group. The incidence of TNEs was almost the same in both groups: 2 (7.4%) of the 27 procedures in the DEX group and 4 (7.0%) of the 57 procedures in the control group (p > 0.99). Moreover, the incidences of symptomatic infarction and TNEs during the entire hospitalization did not differ significantly (symptomatic infarction, p > 0.99; TNEs, p = 0.20). Regarding the DEX effect, the median RASS scores during PODs 0–1 were −1.0 (drowsy) in the DEX group and +1.0 (restless) in the control group, showing a significant difference (p < 0.01). Regarding side effects, bradycardia was observed only in 3 (11.1%) of the 27 procedures in the DEX group (p = 0.03), and hypotension was not observed in any of the cases. CONCLUSIONS In pediatric patients with MMD who are extubated after revascularization surgery, DEX produced appropriate light sedation and analgesia. The risk for symptomatic infarction is almost the same in cases in which DEX is used and those in which it is not; however, neurosurgeons should be cautious of bradycardia and TNEs as potential side effects.

The purpose of this study was to examine the effects of combined revascularization for ischaemic-onset moyamoya disease (MMD) on cerebral haemodynamics by comparing cerebral blood flow (CBF) during the postoperative chronic phase with preoperative CBF. A retrospective cohort of 24 MMD patients (representing 31 surgeries) who received single photon emission computed tomography (SPECT) before and more than 6 months after surgery was investigated. The CBF value of each vascular territory was extracted from SPECT data, and the value relative to the ipsilateral cerebellar value (relative CBF, or RCBF) was calculated. The correlation between the revascularization effect and the proportional change in RCBF before and after surgery (calculated as post-RCBF/pre-RCBF ("post/pre-RCBF")) was analysed. Furthermore, the relationships between changes in neurological symptoms and post/pre-RCBF were investigated. Preoperative and postoperative mean RCBF values were 0.92 ± 0.15 and 0.96 ± 0.13 (p = 0.619) in the anterior cerebral artery territory, 0.99 ± 0.17 and 1.01 ± 0.17 (p = 0.598) in the middle cerebral artery territory and 1.15 ± 0.22 and 1.14 ± 0.19 (p = 0.062) in the posterior cerebral artery territory, respectively. No significant correlation was found between the revascularization score and post/pre-RCBF. The revascularization score and post/pre-RCBF were not significant predictors of worsening neurological symptoms postoperatively. No significant change in RCBF was observed in any vascular territory in the chronic phase after revascularization. Combined revascularization may assist in the redirection of blood flow from the internal to the external carotid system and contribute to CBF maintenance.

Background Two-dimensional digital subtraction angiography (2D-DSA) and conventional three-dimensional digital subtraction angiography (3D-DSA) are used for the detailed analysis of dural arteriovenous fistula (DAVF). Recently, four-dimensional digital subtraction angiography (4D-DSA), a novel technology, has been attracting attention. The current study aimed to evaluate the capability of 4D-DSA in assessing anatomical angioarchitecture in DAVF. Methods In total, 10 consecutive patients with DAVF who underwent 3D-DSA and 4D-DSA at a single institution were included in the analysis. Initially, one-slice multiplanar reconstruction (MPR) images obtained via 4D-DSA and 3D-DSA were compared to investigate the visibility of the feeding artery, fistulous point, and draining vein. Next, 4D-DSA images alone were compared and evaluated with and the MPR images of conventional 3D-DSA in terms of diagnosis of the angioarchitecture. Results In total, six men and four women (with a mean age of 65.6 ± 10.0 years) were included in the study. The MPR image obtained via 3D-DSA had a significantly better visibility of the feeding artery and fistulous point than that acquired via 4D-DSA ( p < 0.05). As for the draining vein, the score was equivalent and not significant. The diagnosis of the vascular architecture of only 4D-DSA images was nearly equivalent to that of MPR images of 3D-DSA. There were no inter-rater differences. Conclusion The MPR images obtained via 4D-DSA may be slightly inferior to those acquired via 3D-DSA in identifying fine angioarchitecture in DAVF. However, they were comparable in terms of diagnostic accuracy.

BACKGROUND Transient neurological deficits (TNDs) develop after cerebral revascularization in patients with moyamoya disease (MMD). The authors report a rare pediatric MMD case with extensive decreased cerebral blood flow (CBF) and prolonged TNDs after combined revascularization. OBSERVATIONS A 9-year-old boy presented with transient left upper limb weakness, and MMD was diagnosed. A right-sided combined surgery was performed. Two years after the surgery, frequent but transient facial (right-sided) and upper limb weakness appeared. The left internal carotid artery terminal stenosis had progressed. Therefore, a left combined revascularization was performed. The patient’s motor aphasia and right upper limb weakness persisted for approximately 10 days after surgery. Magnetic resonance angiography showed that the direct bypass was patent, but extensive decreases in left CBF were observed using single photon emission tomography. With adequate fluid therapy and blood pressure control, the neurological symptoms eventually disappeared, and CBF improved. LESSONS The environment of cerebral hemodynamics is heterogeneous after cerebral revascularization for MMD, and the exact mechanism of CBF decreases was not identified. TNDs are significantly associated with the onset of stroke during the early postoperative period. Therefore, appropriate treatment is desired after determining complex cerebral hemodynamics using CBF studies.

Cerebral revascularization is necessary for pediatric patients younger than 5 years with moyamoya disease (MMD). However, they have a high risk of developing cerebral infarction early after surgery. This study aimed to analyze the risk factors for developing cerebral infarction among these patients.The charts of 21 consecutive patients with MMD (39 surgeries) younger than 5 years who had undergone revascularization at our hospital were retrospectively analyzed. Because cerebral infarction occurring within 1 month after surgery was the primary end point, other clinical information was evaluated, including each surgical procedure. Multivariate analysis of the risk factors for postoperative cerebral infarction was performed.Cerebral infarction occurred after 7 of 39 surgeries (17.9%). Of the 39 surgeries, 23 (59%) included direct and indirect combined revascularization. The incidence of cerebral infarction did not differ significantly between the combined (21.7%) and indirect (12.5%) groups (P = 0.46). Logistic regression showed no association between the revascularization procedure and the occurrence of cerebral infarction after surgery (P = 0.3). However, younger age at surgery was correlated with a higher risk of developing cerebral infarction in the early postoperative period (P = 0.05).No differences were found in the risk of developing cerebral infarction early after surgery as a result of surgical procedures. However, younger patients had higher postoperative risk. Further multicenter research should examine this issue for young pediatric patients with moyamoya at high risk of developing cerebral infarction.

Objective In pediatric patients with moyamoya disease, the pathophysiology of transient neurological deficits and the clinical features of perioperative cerebral blood flow (CBF) changes are unclear. The purpose of this study was to investigate the risk factors of postoperative transient neurological deficits and identify predictors of perioperative CBF changes. Methods This retrospective study included 42 surgical procedures in 28 pediatric patients who underwent surgical revascularization for moyamoya disease, including encephalo-myo-synangiosis (EMS) with or without superficial temporal artery–middle cerebral artery (MCA) anastomosis. Magnetic resonance images and single photon emission computed tomography results were obtained. Brain compression by EMS was also checked in fluid attenuated inversion recovery images. Using single photon emission computed tomography, CBF was measured at each anterior and posterior part of the MCA region. Results Postoperative transient neurological deficits were observed in 12 (28.6%) out of 42 surgical procedures. Brain compression by EMS was a significant risk for transient neurological deficits (P = 0.009). The postoperative CBF in the anterior region increased in 9 cases (21.4%) and decreased in 10 cases (23.8%); in the posterior region, it increased in 12 cases (28.6%) and decreased in 10 cases (23.8%). Preoperative CBF of the anterior region was significantly related to both perioperative CBF changes in the MCA regions (anterior part, P = 0.004; posterior part, P = 0.025). Conclusions Brain compression by EMS is a risk factor for postoperative transient neurological deficits in pediatric patients with moyamoya disease, and preoperative CBF of the anterior MCA region could predict perioperative CBF change in the MCA regions.

Superficial temporal artery (STA) to superior cerebellar artery (SCA) bypass is usually performed via the subtemporal approach (StA), anterior transpetrosal approach (ApA), or combined petrosal approach (CpA), but no study has yet reported a quantitative comparison of the operative field size provided by each approach, and the optimal approach is unclear. The objective of this study is to establish evidence for selecting the approach by using cadaver heads to measure the three-dimensional distances that represent the operative field size for STA–SCA bypass. Ten sides of 10 cadaver heads were used to perform the four approaches: StA, ApA with and without zygomatic arch osteotomy (ApA-ZO− and ApA-ZO+), and CpA. For each approach, the major-axis length and the minor-axis length at the anastomosis site (La-A and Li-A), the major-axis length and the minor-axis length at the brain surface (La-B and Li-B), the depth from the brain surface to the anastomosis site (Dp), and the operating angles of the major axis and the minor axis (OAa and OAi) were measured. Shallower Dp and wider operating angle were obtained in the order CpA, ApA-ZO+, ApA-ZO−, and StA. In all parameters, ApA-ZO− extended the operative field more than StA. ApA-ZO+ extended La-B and OAa more than ApA-ZO−, whereas it did not contribute to Dp and OAi. CpA significantly decreased Dp, and widened OAa and OAi more than ApA-ZO+. ApA and CpA greatly expanded the operative field compared with StA. These results provide criteria for selecting the optimal approach for STA-SCA bypass in light of an individual surgeon’s anastomosis skill level.

Ipsilateral late stroke events occurring after cerebral revascularization for Moyamoya disease (MMD) and their risk factors have not been fully investigated. We retrospectively analyzed 123 patients with MMD who underwent 212 revascularizations. We investigated preoperative demographic data, surgical procedures, and ipsilateral stroke events occurring more than 1 month after surgery. The effect of revascularization and the residual Moyamoya vessel (MMV) score were examined using magnetic resonance angiography (MRA). Then, predictive factors for postoperative late stroke occurrence were evaluated by logistic regression. The mean age was 26 ± 18.4 years (range 1 to 66 years). Ipsilateral late stroke events were present in 11 of 123 (9%) patients. Stroke occurred in 11 out of 212 surgeries (5.2%) on a hemispheric basis. During the 1300.1 hemisphere-years of follow-up more than 1 month after surgery, the annual stroke rate was 0.84%. The postoperative MRA time-of-flight image showed a mean revascularization score of 1.82 ± 0.6 and a mean residual MMV score of 1.91 ± 0.83. Postoperative strokes occurring within 1 month after cerebral revascularization (36.4%, p = 0.0026) and lower revascularization scores (1.82 ± 0.6 vs 2.51 ± 0.59, p = 0.0006) were significant factors related to the presence of ipsilateral late stroke. Logistic regression showed that stroke events within 1 month after revascularization (odds ratio [OR], 9.79; 95% confidence interval [CI], 0.02–0.57; p = 0.0103), low revascularization score (OR, 0.15; 95% CI, 0.001–0.37; p = 0.0069), and high residual MMV score (OR, 16.2; 95% CI, 1.88–187.4; p = 0.0107) were risk factors for ipsilateral stroke more than 1 month after revascularization. MMD patients who have a stroke within 1 month after cerebral revascularization are at high risk for late strokes. Less effective revascularization or remarkable residual MMV are risk factors for late stroke events. Additional revascularization may be considered for patients in such situations. This study was approved by the Bioethics Review Committee of Nagoya University Hospital for the treatment and prognosis of Moyamoya disease (2016-0327).

When superficial temporal artery-middle cerebral artery bypass is combined with indirect methods (e.g., revascularization surgery) to treat Moyamoya disease (MMD), antiplatelet treatment can impact bypass patency, infarction, or hemorrhage complications. Recently, heparin has been proposed as an anticoagulant treatment against white thrombus at the anastomosis site. The study aims to evaluate the effect of aspirin on the perioperative outcomes and investigate the results of heparin treatment for white thrombus. This retrospective study included 74 procedures of combined revascularization surgery for MMD patients who either received or did not receive aspirin. Perioperative outcomes were compared between the two groups. In addition, the effects of heparin treatment for white thrombus were evaluated. The rate of white thrombus at the anastomosis site was significantly higher in the non-aspirin medication group (univariate: p = 0.032, multivariate: p = 0.044) and, accordingly, initial bypass patency was lower in the non-aspirin medication group (p = 0.049). Of the 17 patients with white thrombus development, five received heparin injections, and all white thrombi disappeared; however, there was one case of epidural hematoma and another of subdural hematoma. The risk of hemorrhagic complications was significantly higher in the surgical procedures that received heparin injections (p = 0.021). In MMD patients who received combined revascularization surgery, aspirin medication lowered the occurrence of white thrombus. Heparin injections help to treat white thrombus but can enhance the risk of hemorrhagic complications.

Trigone meningiomas are considered a surgical challenge, as they tend to be considerably large and hypervascularized at the time of presentation. We experienced a case of a large and very hard trigone meningioma that was effectively treated using initial microsurgical feeder occlusion followed by surgery in stages. A 19-year-old woman who presented with loss of consciousness was referred to our hospital for surgical treatment of a brain tumor. Radiological findings were compatible with a left ventricular trigone meningioma extending laterally in proximity to the Sylvian fissure. At initial surgery using the transsylvian approach, main feeders originating from the anterior and lateral posterior choroidal arteries were occluded at the inferior horn; however, only a small section of the tumor could initially be removed because of its firmness. Over time, feeder occlusion resulted in tumor necrosis and a 20% decrease in its diameter; the mass effect was alleviated within 1 year. The residual meningioma was then totally excised in staged surgical procedures after resection became more feasible owing to ischemia-induced partial softening of the tumor. When a trigone meningioma is large and very hard, initial microsurgical feeder occlusion in the inferior horn can be a safe and effective option, and can lead to necrosis, volume decrease, and partial softening of the residual tumor to allow for its staged surgical excision.

Background Collateral artery aneurysms are a source of intracranial hemorrhage in moyamoya disease. Several reports have shown that surgical revascularization leads to the obliteration of collateral artery aneurysms. However, its effect on the prevention of rebleeding has not been established, and the optimal timing of the operation remains unclear. The purpose of the present study is to evaluate the effects of surgical revascularization and to investigate the optimal operation timing in patients with moyamoya disease who have ruptured collateral artery aneurysms on the ventricular wall. Case Description Two patients with moyamoya disease who presented with intraventricular hemorrhage caused by rupture of collateral artery aneurysms on the wall of the lateral ventricle are presented here. In both cases, the aneurysms reruptured approximately 1 month after the initial hemorrhage. Both patients successfully underwent superficial temporal artery–middle cerebral artery anastomosis combined with indirect bypass in the subacute stage. The aneurysms decreased with the development of collateral circulation through the direct bypasses, and rebleeding did not occur after the surgery. Conclusions Because ruptured collateral artery aneurysms on the wall of the lateral ventricle in moyamoya disease are prone to rerupture within 1 month, surgical revascularization may be recommended as soon as the patients are stable and able to withstand the operation.

OBJECTIVE Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive occlusion of the internal carotid artery and the secondary formation of collateral vessels. Patients with MMD have ischemic attacks or intracranial bleeding, but the disease pathophysiology remains unknown. In this study, the authors aimed to identify a gene expression profile specific to the intracranial artery in MMD. METHODS This was a single-center, prospectively sampled, retrospective cohort study. Microsamples of the middle cerebral artery (MCA) were collected from patients with MMD (n = 11) and from control patients (n = 9). Using microarray techniques, transcriptome-wide analysis was performed. RESULTS Comparison of MCA gene expression between patients with MMD and control patients detected 62 and 26 genes whose expression was significantly (p < 0.001 and fold change > 2) up- or downregulated, respectively, in the MCA of MMD. Gene set enrichment analysis of genes expressed in the MCA of patients with MMD revealed positive correlations with genes involved in antigen processing and presentation, the dendritic cell pathway, cytokine pathway, and interleukin-12 pathway, and negative correlations with genes involved in oxidative phosphorylation and DNA repair. Microarray analysis was validated by quantitative polymerase chain reaction. CONCLUSIONS Transcriptome-wide analysis showed upregulation of genes for immune responses and downregulation of genes for DNA repair and oxidative phosphorylation within the intracranial artery of patients with MMD. These findings may represent clues to the pathophysiology of MMD.

Although vascular complications after head trauma is well recognized, basilar artery entrapment within the longitudinal clivus fracture is rare. A 69-year-old man presented with progressive disturbance of consciousness and right hemiplegia after trauma. Computed tomography scan showed a right-sided acute subdural hematoma and multiple skull fractures, including a longitudinal clivus fracture. Magnetic resonance imaging revealed basilar artery occlusion and a small infarction at the ventral part of the pons. On the assumption of acute arterial occlusion caused by thrombus, endovascular thrombectomy was attempted, but resulted in perforation. After the procedure, basilar artery entrapment within the longitudinal clivus fracture turned out to be the cause of the occlusion. The present case suggests that basilar artery entrapment within the longitudinal clivus fracture is a possible cause of neurological deficits after trauma. In this subset, endovascular intervention without a correct diagnosis of this phenomenon is high risk.