Meta-Analysis of Prognosis of Different Treatments for Symptomatic Moyamoya Disease

Combined Direct and Indirect Revascularization for Adults with Moyamoya Disease: A Single-Center Retrospective Study

Background  Moyamoya vasculopathy is a rare neurological disease characterized by the progressive constriction of major intracranial vessels and secondary collateral formation. In the past decade, the popularity of combined bypass surgery has increased. They take advantage of the quick perfusion of direct bypass and collaterals ingrowth from indirect bypass. Objective  This study aimed to describe a single-center experience with surgical management of moyamoya disease (MMD) and moyamoya syndrome (MMS) over 7 years. Materials and Methods  In this retrospective medical records review, we enrolled patients diagnosed with MMD and MMS who were treated with combined surgical revascularization at the Hamad Medical Corporation center between 2015 and 2022. SPSS 26.0 was used to analyze the data. Results  A total of 20 patients were included, with 15% having MMS. The mean age was 37.4 ± 10.26 years, and 60% of them were males. The mean follow-up period was 13.6 months. The modified Rankin score was significantly decreased by 1.9 ± 2.1, p  = 0.0001. Following surgery, no deficits were observed in 16 cases, whereas three were not improved, and one died. Following up on the stroke status, one patient developed a hemorrhagic stroke, and another showed right-side numbness. The postoperative status was substantially linked with the initial clinical presentation ( p  = 0.004). Conclusion  Combined direct and indirect surgical revascularization procedures have favorable outcomes in MMD and MMS patients. Additional rigorous, prospective, controlled, high-quality trials with large-sample are needed to support our results.

Health-Related Quality of Life and Neuropsychological Outcome After EC-IC Bypass Revascularization in Adult Patients With Moyamoya Disease

BACKGROUND AND OBJECTIVES

Patients with Moyamoya disease (MMD) have an above-average incidence of neuropsychological impairment and psychiatric comorbidities such as depression. Prevalence and correlation with preoperative imaging findings were identified in previous studies, and a reduced health-related quality of life (HRQOL) has been shown. This study investigates changes in neuropsychological performance and HRQOL after revascularization.

METHODS

Thirty-two adult patients with MMD (23 female, 9 male; mean age 39.1 year ±14.7) with revascularization were included in this retrospective cohort study, and their results of structured neuropsychological testing were analyzed preoperatively and 1 year postoperatively. Sensorimotor deficits assessed with the National Institutes of Health Stroke Scale were considered to be possible confounders.

RESULTS

Patients with preoperatively poor test results showed improvement in various items such as psychological well-being (95% CI [0.55-2.25], P = .002), vitality (95% CI [0.23-1.68], P = .007), general health perception (95% CI [0.09-1.44], P = .014), psychoticism (95% CI [-12.24 to -4.85], P < .001), and psychomotor processing speed (95% CI [0.10-1.14], P = .010), whereas the intensity of depression fell by a mean of 6.9 points (95% CI [-10.14 to -3.61], P < .001). For patients without preoperative neuropsychological or HRQOL deterioration, preservation of these functions without relevant worsening after revascularization was observed. Significant improvement in vitality, psychological well-being, psychoticism, psychomotor processing speed, and depression were also seen in patients with unchanged National Institutes of Health Stroke Scale.

CONCLUSION

Chronic steno-occlusive cerebral hypoperfusion in patients with MMD not only may lead to neurological deficits but is also associated with neuropsychological impairment, reduced HRQOL, and increased depression. The results of this study show that patients with preoperative neuropsychological deterioration might benefit from revascularization surgery, whereas patients without preoperative impairment continue to remain stable postoperatively. Neuropsychological assessment should be routinely evaluated and considered a relevant variable when determining treatment for patients with MMD.

Association of Bypass Surgery and Mortality in Moyamoya Disease

BACKGROUND

Patients with moyamoya disease (MMD) have a high risk of stroke or death. We investigated whether extracranial to intracranial bypass surgery can reduce mortality by preventing strokes in patients with MMD.

METHODS AND RESULTS

This nationwide retrospective cohort study encompassed patients with MMD registered under the Rare Intractable Diseases program via the Relieved Co-Payment Policy between 2006 and 2019, using the Korean National Health Insurance Service database. Following a 4-year washout period, landmark analyses were employed to assess mortality and stroke occurrence between the bypass surgery group and the nonsurgical control group at specific time points postindex date (1 month and 3, 6, 12, and 36 months). The study included 18 480 patients with MMD (mean age, 40.7 years; male to female ratio, 1:1.86) with a median follow-up of 5.6 years (interquartile range, 2.5-9.3; mean, 6.1 years [SD, 4.0 years]). During 111 775 person-years of follow-up, 265 patients in the bypass surgery group and 1144 patients in the nonsurgical control group died (incidence mortality rate of 618.1 events versus 1660.3 events, respectively, per 105 person-years). The overall adjusted hazard ratio (HR) revealed significantly lower all-cause mortality in the bypass surgery group from the 36-month landmark time point, for any stroke mortality from 3- and 6-month landmark time points, and for hemorrhagic stroke mortality from the 6-month landmark time point. Furthermore, the overall adjusted HRs for hemorrhagic stroke occurrence were beneficially maintained from all 5 landmark time points in the bypass surgery group.

CONCLUSIONS

Bypass surgery in patients with MMD was associated with a lower risk of all-cause and hemorrhagic stroke mortality and hemorrhagic stroke occurrence compared with nonsurgical control.

Adult Moyamoya Disease and Syndrome: Current Perspectives and Future Directions: A Scientific Statement From the American Heart Association/American Stroke Association

Adult moyamoya disease and syndrome are rare disorders with significant morbidity and mortality. A writing group of experts was selected to conduct a literature search, summarize the current knowledge on the topic, and provide a road map for future investigation. The document presents an update in the definitions of moyamoya disease and syndrome, modern methods for diagnosis, and updated information on pathophysiology, epidemiology, and both medical and surgical treatment. Despite recent advancements, there are still many unresolved questions about moyamoya disease and syndrome, including lack of unified diagnostic criteria, reliable biomarkers, better understanding of the underlying pathophysiology, and stronger evidence for treatment guidelines. To advance progress in this area, it is crucial to acknowledge the limitations and weaknesses of current studies and explore new approaches, which are outlined in this scientific statement for future research strategies.

Association of moyamoya vasculopathy with autoimmune disease: a systematic review and pooled analysis

Despite more than six decades of extensive research, the etiology of moyamoya disease (MMD) remains unknown. Inflammatory or autoimmune (AI) processes have been suggested to instigate or exacerbate the condition, but the data remains mixed. The objective of the present systematic review was to summarize the available literature investigating the association of MMD and AI conditions as a means of highlighting potential treatment strategies for this subset of moyamoya patients. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the PubMed, Embase, Scopus, Web of Science, and Cochrane databases were queried to identify studies describing patients with concurrent diagnoses of MMD and AI disease. Data were extracted on patient demographics, clinical outcomes, and treatment. Stable or improved symptoms were considered favorable outcomes, while worsening symptoms and death were considered unfavorable. Quantitative pooled analysis was performed with individual patient-level data. Of 739 unique studies identified, 103 comprising 205 unique patients (80.2% female) were included in the pooled analysis. Most patients (75.8%) identified as Asian/Pacific Islanders, and the most commonly reported AI condition was Graves' disease (57.6%), with 55.9% of these patients presenting in a thyrotoxic state. Of the 148 patients who presented with stroke, 88.5% of cases (n = 131) were ischemic. Outcomes data was available in 152 cases. There were no significant baseline differences between patients treated with supportive therapy alone and those receiving targeted immunosuppressant therapy. Univariable logistic regression showed that surgery plus medical therapy was more likely than medical therapy alone to result in a favorable outcome. On subanalysis of operated patients, 94.1% of patients who underwent combined direct and indirect bypass reported favorable outcomes, relative to 76.2% of patients who underwent indirect bypass and 82% who underwent direct bypass (p < 0.05). On univariable analysis, the presence of multiple AI disorders was associated with worse outcomes relative to having a single AI disorder. Autoimmune diseases have been uncommonly reported in patients with MMD, but the presence of multiple AI comorbidities portends poorer prognosis. The addition of surgical intervention appears to improve outcomes and for patients deemed surgical candidates, combined direct and indirect bypass appears to offer better outcomes that direct or indirect bypass alone.

Advances in Management of the Stroke Etiology One-Percenters

PURPOSE OF REVIEW

Uncommon causes of stroke merit specific attention; when clinicians have less common etiologies of stoke in mind, the diagnosis may come more easily. This is key, as optimal management will in many cases differs significantly from "standard" care.

RECENT FINDINGS

Randomized controlled trials (RCT) on the best medical therapy in the treatment of cervical artery dissection (CeAD) have demonstrated low rates of ischemia with both antiplatelet and vitamin K antagonism. RCT evidence supports the use of anticoagulation with vitamin K antagonism in "high-risk" patients with antiphospholipid antibody syndrome (APLAS), and there is new evidence supporting the utilization of direct oral anticoagulation in malignancy-associated thrombosis. Migraine with aura has been more conclusively linked not only with increased risk of ischemic and hemorrhagic stroke, but also with cardiovascular mortality. Recent literature has surprisingly not provided support the utilization of L-arginine in the treatment of patients with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS); however, there is evidence at this time that support use of enzyme replacement in patients with Fabry disease. Additional triggers for reversible cerebral vasoconstriction syndrome (RCVS) have been identified, such as capsaicin. Imaging of cerebral blood vessel walls utilizing contrast-enhanced MRA is an emerging modality that may ultimately prove to be very useful in the evaluation of patients with uncommon causes of stroke. A plethora of associations between cerebrovascular disease and COVID-19 have been described. Where pertinent, authors provide additional tips and guidance. Less commonly encountered conditions with updates in diagnosis, and management along with clinical tips are reviewed.

Clinical Efficacy of Superficial Temporal Artery-middle Cerebral Artery Bypass Grafting Surgery Combined With Temporal Muscle Patch on Patients With Moyamoya Disease

OBJECTIVE

To analyze the clinical efficacy of superficial temporal artery-middle cerebral artery (STA-MCA) bypass grafting surgery combined with temporal muscle patch and STA-MCA bypass grafting surgery alone on patients with moyamoya disease.

METHODS

Totally 73 patients confirmed with moyamoya disease in our hospital between January 2019 and December 2021 were enrolled. Among them, 43 patients treated with STA-MCA bypass grafting surgery combined with temporal muscle patch were assigned to the experiment group, whereas 30 patients treated with STA-MCA bypass grafting surgery alone to the control group. The following items of the 2 groups were compared: clinical efficacy, total effective rate, and disease control rate 6 months after surgery, the changes of modified Rankin Scale (mRS) and Karnofsky performance scale (KPS) scores before and on the seventh day and 6 months after surgery, and changes of Glasgow coma scale scores before and 24 hours after surgery. In addition, the incidences of cerebral ischemia and cerebral hemorrhage within 1 year after surgery were counted. The cerebral perfusion-associated indexes including relative mean transit time (rMTT), relative time-to-peak, relative cerebral blood flow (rCBF), and relative cerebral blood volume (rCBV) on the seventh day and 6 months after surgery were compared between the 2 groups, and the predictive value of cerebral perfusion-associated indexes before surgery for clinical efficacy on patients was analyzed.

RESULTS

The Glasgow coma scale score after surgery ( P >0.05) was similar between the 2 groups, but the clinical efficacy and total effective rate of the 2 groups were notably different (both P <0.05). Compared with those before surgery, mRS scores of both groups declined, whereas KPS scores increased (both P <0.05) on the seventh day after surgery. In addition, compared with those before surgery and on the seventh day after surgery, mRS scores of both groups decreased 6 months after surgery, whereas KPS scores increased (both P <0.05). Both the groups showed decreased rMTT and rTPP, and increased rCBF and rCBV on the seventh day after surgery than those before surgery (all P <0.05). In addition, both the groups still showed decreased rMTT and rTPP, and increased rCBF and rCBV 6 months after surgery than those before surgery and on the seventh day after surgery (all P <0.05). Most notably, the experimental group displayed improved cerebral perfusion-associated indexes than the control group 6 months after surgery (all P <0.05). The relief group showed notably higher rCBF and rCBV levels than the nonrelief group (both P <0.05). According to ROC analysis, the areas under the curves of rCBF and rCBV in forecasting the clinical efficacy on patients were 0.842 and 0.823, respectively.

CONCLUSION

Superficial temporal artery-middle cerebral artery bypass grafting surgery combined with temporal muscle patch can deliver a higher total clinical curative rate for patients with moyamoya disease and can alleviate their coma.

Combined direct and indirect superficial temporal artery-to-middle cerebral artery bypass with a hinged bone flap: how I do it

BACKGROUND

Superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass is a critical treatment for moyamoya disease and steno-occlusive cerebrovascular disease. Combined bypass (direct + indirect) optimizes the chance of durable flow augmentation but can complicate wound closure from tissue disruption.

METHODS

We describe our technique for combined direct and indirect (encephaloduromyosynangiosis; EDAMS) STA-MCA bypass using a hinged bone flap. In addition to a direct bypass, EDAMS provides multiple sources for indirect revascularization. The hinged bone flap gently approximates the muscle and pia for secondary vascular ingrowth.

CONCLUSIONS

Combined STA-MCA bypass with a hinged bone flap safely maximizes revascularization potential.

Surgical techniques and indications for treatment of adult moyamoya disease

Moyamoya disease (MMD) is a chronic, progressive cerebrovascular disease involving the occlusion or stenosis of the terminal portion of the internal carotid artery (ICA) and the proximal anterior and middle cerebral arteries. Adults with MMD have been shown to progressively accumulate neurological and cognitive deficits without treatment, with a mortality rate double that of pediatric patients with MMD. Surgical intervention is the mainstay of treatment to prevent disease progression and improve clinical outcomes. Several different types of bypasses can be utilized for revascularization in MMD, including indirect, direct, and combined forms of extracranial-to-intracranial (EC-IC) bypass. Overall, the choice of appropriate technique requires consideration of the age of the patient, preoperative hemodynamics, neurologic status, and territories most at risk and in need of revascularization. Here, we will review the indications and surgical techniques for the treatment of adult MMD. Step-by-step instructions for performing several bypass variants with technical pearls are discussed.

Revascularization Is Associated With a Reduced Stroke Risk in Patients With Sickle Cell-Associated Moyamoya Syndrome

BACKGROUND

Moyamoya syndrome refers to a progressive stenosis of the internal carotid arteries and can be associated with sickle cell disease. These codiagnoses result in severe risk for stroke, even in patients on optimal medical management. Surgical revascularization has been shown to be safe in small case series.

OBJECTIVE

To evaluate the efficacy of revascularization with direct comparison to a medically managed control group within a single institution.

METHODS

A retrospective cohort study of medically managed vs surgically revascularized patients with moyamoya syndrome and sickle cell disease was conducted. Demographic data and outcomes including the number of prediagnosis, postdiagnosis, and postrevascularization strokes were collected. Risk factors for stroke were identified using a binary logistic regression model, and stroke rates and mortality between groups were compared.

RESULTS

Of the 29 identified patients, 66% were medically managed and 34% underwent surgical revascularization (50% direct and 50% indirect). Calculated stroke rates were 1 per 5.37 (medical management), 1 per 3.43 (presurgical revascularization), and 1 per 23.14 patient-years (postsurgical revascularization). There was 1 surgical complication with no associated permanent deficits. No risk factors for stroke after time of diagnosis were found to be significant.

CONCLUSION

The results of this study demonstrate that revascularization is associated with a significant reduction in stroke risk, both relative to prerevascularization rates and compared with medical management. According to these findings, surgical revascularization offers a safe and durable preventative therapy for stroke and should be pursued aggressively in this patient population.

Salvage multiple burr hole surgery in patients with Moyamoya disease: efficacy evaluation using probabilistic independent component analysis of dynamic susceptibility contrast perfusion MRI

PURPOSE

Multiple burr hole surgery is considered to be an option for achieving indirect revascularization in patients with ischemic Moyamoya disease (MMD). We aimed to investigate the efficacy of stand-alone multiple burr hole surgery for salvage revascularization in patients with MMD by assessing the hemodynamic changes via normalized time-to-peak (nTTP) analysis and independent component analysis (ICA) of preoperative and postoperative dynamic susceptibility contrast (DSC) perfusion MRI data.

METHODS

The DSC perfusion MRI data of 25 hemispheres from 21 patients with MMD, who underwent multiple burr hole surgery for salvage revascularization due to persistent or recurrent symptoms after primary revascularization with modified encephaloduroarteriosynangiosis (mEDAS), were analyzed. The nTTP, which was measured using the region of interests covering the entire surgical hemisphere, was compared between the preoperative and postoperative images. ICA was used to compare the relative arterial and venous components of the surgical hemispheres between the respective preoperative and postoperative images.

RESULTS

The median postoperative nTTP (1.80 s) was significantly shorter than the median preoperative nTTP (4.10 s) (P < 0.001). The postoperative relative arterial component of the surgical hemisphere (median: 0.04) was significantly higher than the preoperative relative arterial component (median: - 0.02, P < 0.001). In contrast, the postoperative relative venous component of the surgical hemisphere (median: - 0.05) was significantly lower than the preoperative value (median: 0.05, P < 0.001).

CONCLUSION

The improvement in cerebral perfusion parameters observed on postoperative DSC perfusion MRI demonstrated that stand-alone multiple burr hole surgery could be a favorable salvage revascularization technique after mEDAS failure in patients with ischemic MMD.

A Meta-Analysis of Using Protamine for Reducing the Risk of Hemorrhage During Carotid Recanalization: Direct Comparisons of Post-operative Complications

Background: Protamine can decrease the risk of hemorrhage during carotid recanalization. However, it may cause severe side effects. There is no consensus on the safety and efficacy of protamine during surgery. Thus, we conduct a comprehensive review and meta-analysis to compare the differences between the protamine and the no-protamine group.

Method: We systematically obtained literature from Medline, Google Scholar, Cochrane Library, and PubMed electronic databases. All four databases were scanned from 1937 when protamine was first adopted as a heparin antagonist until February 2021. The reference lists of identified studies were manually checked to determine other eligible studies that qualify. The articles were included in this meta-analysis as long as they met the criteria of PICOS; conference or commentary articles, letters, case report or series, and animal observation were excluded from this study. The Newcastle-Ottawa Quality Assessment Scale and Cochrane Collaboration’s tool are used to assess the risk of bias of each included observational study and RCT, respectively. Stata version 12.0 statistical software (StataCorp LP, College Station, Texas) was adopted as statistical software. When I2 &lt; 50%, we consider that the data have no obvious heterogeneity, and we conduct a meta-analysis using the fixed-effect model. Otherwise, the random-effect model was performed.

Result: A total of 11 studies, consisting of 94,618 participants, are included in this study. Our analysis found that the rate of wound hematoma had a significant difference among protamine and no-protamine patients (OR = 0.268, 95% CI = 0.093 to 0.774, p = 0.015). Furthermore, the incidence of hematoma requiring re-operation (0.7%) was significantly lower than that of patients without protamine (1.8%). However, there was no significant difference in the incidence of stroke, wound hematoma with hypertension, transient ischemic attacks (TIA), myocardial infarction (MI), and death.

Conclusion: Among included participants undergoing recanalization, the use of protamine is effective in reducing hematoma without increasing the risk of having other complications. Besides, more evidence-based performance is needed to supplement this opinion due to inherent limitations.

Moyamoya disease and syndrome: a review

Moyamoya disease is a chronic occlusive cerebrovascular disease that is non-inflammatory and non-atherosclerotic. It is characterized by endothelial hyperplasia and fibrosis of the intracranial portion of the carotid artery and its proximal branches, leading to progressive stenosis and occlusion, often clinically manifesting as ischemic or hemorrhagic stroke with high rates of morbidity and mortality. On cerebral angiography, the formation of collateral vessels has the appearance of a puff of smoke (moyamoya in Japanese), which became more conspicuous with the refinement of modern imaging techniques. When there is associated disease, it is known as moyamoya syndrome. Treatments are currently limited, although surgical revascularization may prevent ischemic events and preserve quality of life. In this review, we summarize recent advances in moyamoya disease, covering aspects of epidemiology, etiology, presentation, imaging, and treatment strategies.

Moyamoya Disease in a Young Female With Neurofibromatosis Type 1

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive stenosis of the terminal portions of the internal carotid arteries (ICAs) and the development of a network of abnormal collateral vessels. This case depicts a 25-year-old African American female patient with neurofibromatosis type 1 (NF-1), whose initial hospital presentation occurred in a hypertensive emergency setting. Surveillance studies with magnetic resonance imaging (MRI) revealed multiple asymptomatic right cortical strokes. Genetic testing evidenced a novel, unique pathogenic variant on the NF-1 gene. The patient underwent combined bypass surgery first and then was placed on aspirin and a blood pressure control regimen. Our case illustrates the need for clinicians to include moyamoya disease in the list of differential diagnoses when encountering a young patient, without major risk factors, presenting with ischemic stroke. It should be considered even with no known history of previously diagnosed MMD or NF-1, as these pathologies may have yet to be evaluated in subclinical cases.

Progression in Moyamoya Disease: Clinical Feature, Neuroimaging Evaluation and Treatment

Moyamoya disease (MMD) is a chronic cerebrovascular disease characterized by progressive stenosis of the arteries of the circle of Willis, with the formation of collateral vascular network at the base of the brain. Its clinical manifestations are complicated. Numerous studies have attempted to clarify the clinical features of MMD, including its epidemiology, genetic characteristics, and pathophysiology. With the development of neuroimaging techniques, various neuroimaging modalities with different advantages have deepened the understanding of MMD in terms of structural, functional, spatial, and temporal dimensions. At present, the main treatment for MMD focuses on neurological protection, cerebral blood flow reconstruction, and neurological rehabilitation, such as pharmacological treatment, surgical revascularization, and cognitive rehabilitation. In this review, we discuss recent progress in understanding the clinical features, in the neuroimaging evaluation and treatment of MMD.

Pediatric Stroke: Overview and Recent Updates

Stroke can occur at any age or stage in life. Although it is commonly thought of as a disease amongst the elderly, it is important to highlight the fact that it also affects infants and children. In both populations, strokes have a high rate of morbidity and mortality. Arguably, it is more detrimental in the pediatric population given the occurrence at a younger age and therefore, a longer duration of disability, potentially over the entire lifespan. The high rate of morbidity and mortality in pediatrics is attributed to significant delays in diagnosis, as well as misdiagnosis. Acute stroke management is time dependent. Patients who receive acute treatment with either intravenous (IV) tissue plasminogen activator (tPA) or mechanical thrombectomy, have improved mortality and functional outcomes. Additionally, the earlier treatment is initiated, the higher the likelihood of preserving penumbra, restoring cerebral blood flow and potentially reversing symptoms, thereby limiting disability. Prompt identification is essential as it leads to improved patient care in such a narrow therapeutic window. It enhances the care received during hospitalization and reduces the risk of early stroke recurrence. Despite limited data and lack of large randomized clinical trials in pediatrics, both IV tPA and mechanical thrombectomy have been successfully used. Bridging the gap of acute stroke management in the pediatric population is an essential part of minimizing adverse outcomes. In this review, we discuss the epidemiology of pediatric stroke, the diverse etiologies, presentation as well as both acute and preventative management.

Surgical Management of Failed Revascularization in Moyamoya Vasculopathy

Objectives: Moyamoya vasculopathy (MMV) is a rare stenoocclusive cerebrovascular disease associated with increased risk of ischemic and hemorrhagic stroke, which can be treated using surgical revascularization techniques. Despite well-established neurosurgical procedures performed in experienced centers, bypass failure associated with neurological symptoms can occur. The current study therefore aims at characterizing the cases of bypass failure and repeat revascularization at a single center.

Methods: A single-center retrospective analysis of all patients treated with revascularization surgery for MMV between January 2007 and December 2019 was performed. Angiographic data, cerebral blood flow analysis [H₂O PET or single-photon emission CT (SPECT)], MRI, and clinical/operative data including follow-up assessments were reviewed.

Results: We identified 308 MMV patients with 405 surgically treated hemispheres. Of the 405 hemispheres treated, 15 patients (3.7%) underwent repeat revascularization (median age 38, time to repeat revascularization in 60% of patients was within 1 year of first surgery). The most common cause of repeat revascularization was a symptomatic bypass occlusion (80%). New ischemic lesions were found in 13% of patients prior to repeat revascularization. Persistence of reduced or progressive worsening of cerebrovascular reserve capacity (CVRC) compared with preoperative status was observed in 85% of repeat revascularization cases. Intermediate-flow bypass using a radial artery graft was most commonly used for repeat revascularization (60%) followed by re-superficial temporal artery to middle cerebral artery (re-STA-MCA) bypass (26%). High-flow bypass using a saphenous vein graft and using an occipital artery to MCA bypass was each used once. Following repeat revascularization, no new ischemic events were recorded.

Conclusion: Overall, repeat revascularization is needed only in a small percentage of the cases in MMV. A rescue surgery should be considered in those with neurological symptoms and decreased CVRC. Intermediate-flow bypass using a radial artery graft is a reliable technique for patients requiring repeat revascularization. Based on our institutional experience, we propose an algorithm for guiding the decision process in cases of bypass failure.

Controversies and Advances in Adult Intracranial Bypass Surgery in 2020

Cerebral revascularization utilizing a variety of bypass techniques can provide either flow augmentation or flow replacement in the treatment of a range of intracranial pathologies, including moyamoya disease, intracranial atherosclerotic disease, and complex aneurysms that are not amenable to endovascular or simple surgical techniques. Though once routine, the publication of high-quality prospective evidence, along with the development of flow-diverting stents, has limited the indications for extracranial-to-intracranial (EC-IC) bypass. Nevertheless, advances in imaging, assessment of cerebral hemodynamics, and surgical technique have changed the risk-benefit calculus for EC-IC bypass. New variations of revascularization surgery involving multiple anastomoses, flow preserving solutions, IC-IC constructs, and posterior circulation bypasses have been pioneered for otherwise difficult to treat pathology including giant aneurysms, dolichoectasia, and medically refractory intracranial atherosclerosis. This review provides a practical update on recent advances in adult intracranial bypass surgery.

Predicting Decreased Activities of Daily Living in Patients with Moyamoya Disease after Revascularization: Development and Assessment of a New Predictive Nomogram

The aim of this study was to develop and validate a nomogram model to predict the risk of decreased activities of daily living (ADLs) in patients with moyamoya disease (MMD) following revascularization. The nomogram model was constructed based on data from 292 patients with MMD that were treated at Qilu Hospital of Shandong University from January 2018 to June 2019. The prediction model was assessed using a dataset of 119 patients with MMD collected from July 2019 to June 2020. Patients were evaluated with a general information questionnaire and the Mini Mental Status Examination, Hospital Anxiety and Depression Scale, Social Support Rating Scale, and ADL Scale. Multivariable logistic regression analysis was applied to build a prediction model incorporating the features selected in the least absolute shrinkage and selection operator regression model. Discrimination, calibration, and clinical usefulness of the prediction model were assessed using receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis. Predictors contained in the nomogram included gender, age, monthly income, hypertension, and cognitive function and depression scores. The areas under the ROC curves of the training and testing datasets were 0.938 and 0.853, respectively. The prediction model displayed good calibration, and the decision curve analysis showed that it had a wide range of clinical applications. This novel predictive could be conveniently used to predict the risk of the decreased living activity ability in patients with MMD.

Surgical revascularization for Moyamoya disease in the United States: A cost-effectiveness analysis

Objective

Moyamoya disease (MMD) is a vasculopathy of the internal carotid arteries with ischemic and hemorrhagic sequelae. Surgical revascularization confers upfront peri-procedural risk and costs in exchange for long-term protective benefit against hemorrhagic disease. The authors present a cost-effectiveness analysis (CEA) of surgical versus non-surgical management of MMD.

Methods

A Markov Model was used to simulate a 41-year-old suffering a transient ischemic attack (TIA) secondary to MMD and now faced with operative versus nonoperative treatment options. Health utilities, costs, and outcome probabilities were obtained from the CEA registry and the published literature. The primary outcome was incremental cost-effectiveness ratio which compared the quality adjusted life years (QALYs) and costs of surgical and nonsurgical treatments. Base-case, one-way sensitivity, two-way sensitivity, and probabilistic sensitivity analyses were performed with a willingness to pay threshold of $50,000.

Results

The base case model yielded 3.81 QALYs with a cost of $99,500 for surgery, and 3.76 QALYs with a cost of $106,500 for nonsurgical management. One-way sensitivity analysis demonstrated the greatest sensitivity in assumptions to cost of surgery and cost of admission for hemorrhagic stroke, and probabilities of stroke with no surgery, stroke after surgery, poor surgical outcome, and death after surgery. Probabilistic sensitivity analyses demonstrated that surgical revascularization was the cost-effective strategy in over 87.4% of simulations.

Conclusions

Considering both direct and indirect costs and the postoperative QALY, surgery is considerably more cost-effective than non-surgical management for adults with MMD.

Moyamoya Disease: A Review of Current Literature

Moyamoya disease (MMD) is an infrequent disease of cerebral vasculature characterized by long-standing and progressive occlusion of large intracranial arteries. It is seen predominantly in the East Asian population. Most of the cases of MMD are sporadic, but there is a small percentage that is familial. The mode of inheritance is reported to be autosomal dominant with incomplete penetrance. Studies show that the susceptibility gene of MMD is located on chromosome 17. The clinical presentation is variable and is influenced by the age and geographic region of the patient. Children mainly present with ischemia-related neurologic episodes whereas MMD in adults can manifest as either an ischemic event or an intracranial hemorrhage (ICH). The gold standard investigation for diagnosis is cerebral angiography which reveals a smoky appearance of arteries at the base of the skull, thus granting the disease its name. The treatment is mostly surgical and includes direct and indirect revascularization procedures, which prevent the recurrence of both ischemic and hemorrhagic strokes. However, combination revascularization procedures are now on the rise due to studies showing better long-term outcomes. The aim of the article is to critically analyze the current literature and updates on various aspects of MMD including, but not limited to, etiology, diagnosis, and treatment.

Moyamoya Syndrome in a 32-Year-Old Male With Sickle Cell Anemia

Moyamoya disease (MMD) is an unusual vasculopathy in which the blood vessels of the brain are occluded, resulting in thrombosis. When MMD occurs in association with an underlying pathology, it is known as moyamoya syndrome. The association of moyamoya syndrome with sickle cell disease is uncommon. Herein, we report a case of moyamoya syndrome in a 32-year-old male adult patient.

An Interesting Case of Moyamoya Disease, a Rare Cause of Transient Ischemic Attacks

Moyamoya disease is a rare, chronic, idiopathic progressive disease characterized by irreversible vascular occlusion of the vessels of the Circle of Willis. The disease was initially considered to be limited to the East Asian population, but now the disease is being reported all over the globe in people of multiple ethnicities. It is crucial that clinicians are aware of the disease and its presentation to prevent under-recognition of the condition. We describe the case of a 44-year-old Caucasian female with a history of hypertension, depression, gastroesophageal reflux disease (GERD), and morbid obesity diagnosed with Moyamoya disease after she presented to the emergency department with recurrent stroke-like symptoms.

A critical appraisal of bypass surgery in moyamoya disease

Moyamoya disease (MMD) is a complex cerebrovascular disorder about which little is known. Conventionally, revascularization surgery is recommended for patients, despite an absence of conclusive data from adequate clinical trials. Underscoring the uncertainty that exists in treating MMD patients, investigators continue to present data comparing revascularization with conservative or medical management, most of which originates from East Asia where MMD is most prevalent. The purpose of this manuscript is to review contemporary large case series, randomized trials, and recent meta-analyses that compare surgical and medical treatments in adult patients with MMD, and to critically analyze the modern literature in the context of current practice standards. Data from the available literature is limited, but revascularization seems superior to conservative therapy in adult patients presenting with hemorrhage, and in preventing future hemorrhages. Conversely, evidence that surgery is superior to medical therapy is not convincing in adult patients presenting with cerebral ischemia, or for the prevention of future ischemic events. In contrast to East Asian populations, MMD in Europe and in the Americas is predominantly an ischemic disease that presents in adulthood. Adequate multinational trials are warranted.

Heritable and non-heritable uncommon causes of stroke

Despite intensive investigations, about 30% of stroke cases remains of undetermined origin. After exclusion of common causes of stroke, there is a number of rare heritable and non-heritable conditions, which often remain misdiagnosed, that should be additionally considered in the diagnosis of cryptogenic stroke. The identification of these diseases requires a complex work up including detailed clinical evaluation for the detection of systemic symptoms and signs, an adequate neuroimaging assessment and a careful family history collection. The task becomes more complicated by phenotype heterogeneity since stroke could be the primary or unique manifestation of a syndrome or represent just a manifestation (sometimes minor) of a multisystem disorder. The aim of this review paper is to provide clinicians with an update on clinical and neuroradiological features and a set of practical suggestions for the diagnostic work up and management of these uncommon causes of stroke. The identification of these stroke causes is important to avoid inappropriate and expensive diagnostic tests, to establish appropriate management measures, including presymptomatic testing, genetic counseling, and, if available, therapy. Therefore, physicians should become familiar with these diseases to provide future risk assessment and family counseling.

Clinical efficacy of extracranial-intracranial bypass for the treatment of adult patients with moyamoya disease: A protocol of systematic review of randomized controlled trials

BACKGROUND

Moyamoya disease (MMD) is a major health concern associated with blocked arteries at the base of the brain. The aim of this study will synthesize the current evidence of the efficacy and safety of extracranial-intracranial bypass (EIB) for the treatment of adult patients with MMD.

METHODS

A systematically and comprehensively literature search will be performed in PubMed, EMBASE, Web of Science, CENTRAL, CINAHL, AMED, CBM, and CNKI to identify relevant randomized controlled trails (RCTs) investigating the efficacy and safety of EIB for treating MMD. We will search all above electronic databases from their inception to the July 30, 2019. Two review authors will independently perform study selection, data extraction, and conduct risk of bias evaluation using Cochrane risk of bias tool. We will also explore heterogeneity across studies. RevMan 5.3 software will be applied for statistical analysis performance.

RESULTS

This study will evaluate the efficacy and safety of EIB for the treatment of adult patients with MMD.

CONCLUSION

The results of this study will provide latest evidence of the efficacy and safety of EIB for MMD.

DISSEMINATION AND ETHICS

This study is based on published studies, thus, no ethical consideration is needed. The results of this study are expected to be published in peer-reviewed journals or will be presented on conference meeting.Systematic review registration: PROSPERO CRD42019155839.