Postoperative Cerebral Infarction Risk Factors and Postoperative Management of Pediatric Patients with Moyamoya Disease

The Potential Role of Preoperative Posterior Cerebral Artery Involvement in Predicting Postoperative Transient Neurological Deficits and Ischemic Stroke After Indirect Revascularization in Patients With Moyamoya Disease

OBJECTIVE

Transient neurological deficits (TNDs) are known to develop after direct bypass for Moyamoya disease and may be risk factors for subsequent stroke. However, the factors involved in the development of TNDs and stroke after indirect revascularization alone, including their association with subsequent stroke, remain unclear. The purpose of this study was to investigate this issue.

METHODS

The subjects of the study were 30 patients with Moyamoya disease who underwent a total of 40 indirect revascularization procedures at our institution. Clinical and radiological data were collected retrospectively. To examine factors associated with the development of postoperative TND/stroke/asymptomatic disease, the clinical characteristics of each group were statistically compared.

RESULTS

The mean age at surgery was 7 years (range 1-63). TNDs developed after surgery in 9 out of 40 patients (22.5%). Stroke in the acute postoperative period occurred in 3 patients (7.5%), all of whom experienced cerebral infarctions. Demographic data and preoperative clinical information were not different between the groups. However, posterior cerebral artery involvement on preoperative imaging was significantly associated with the development of TNDs and stroke (P = 0.006). Furthermore, postoperative stroke was associated with unfavorable outcomes (P = 0.025).

CONCLUSIONS

Posterior cerebral artery involvement is significantly associated with the occurrence of TNDs. In contrast, TNDs after indirect revascularization have little relationship with the subsequent development of stroke. TNDs usually resolve without new strokes, and a better understanding of this particular pathology could help establish an optimal treatment regimen.

Pediatric Moyamoya Revascularization Perioperative Care: A Modified Delphi Study

BACKGROUND

Surgical revascularization decreases the long-term risk of stroke in children with moyamoya arteriopathy but can be associated with an increased risk of stroke during the perioperative period. Evidence-based approaches to optimize perioperative management are limited and practice varies widely. Using a modified Delphi process, we sought to establish expert consensus on key components of the perioperative care of children with moyamoya undergoing indirect revascularization surgery and identify areas of equipoise to define future research priorities.

METHODS

Thirty neurologists, neurosurgeons, and intensivists practicing in North America with expertise in the management of pediatric moyamoya were invited to participate in a three-round, modified Delphi process consisting of a 138-item practice patterns survey, anonymous electronic evaluation of 88 consensus statements on a 5-point Likert scale, and a virtual group meeting during which statements were discussed, revised, and reassessed. Consensus was defined as ≥ 80% agreement or disagreement.

RESULTS

Thirty-nine statements regarding perioperative pediatric moyamoya care for indirect revascularization surgery reached consensus. Salient areas of consensus included the following: (1) children at a high risk for stroke and those with sickle cell disease should be preadmitted prior to indirect revascularization; (2) intravenous isotonic fluids should be administered in all patients for at least 4 h before and 24 h after surgery; (3) aspirin should not be discontinued in the immediate preoperative and postoperative periods; (4) arterial lines for blood pressure monitoring should be continued for at least 24 h after surgery and until active interventions to achieve blood pressure goals are not needed; (5) postoperative care should include hourly vital signs for at least 24 h, hourly neurologic assessments for at least 12 h, adequate pain control, maintaining normoxia and normothermia, and avoiding hypotension; and (6) intravenous fluid bolus administration should be considered the first-line intervention for new focal neurologic deficits following indirect revascularization surgery.

CONCLUSIONS

In the absence of data supporting specific care practices before and after indirect revascularization surgery in children with moyamoya, this Delphi process defined areas of consensus among neurosurgeons, neurologists, and intensivists with moyamoya expertise. Research priorities identified include determining the role of continuous electroencephalography in postoperative moyamoya care, optimal perioperative blood pressure and hemoglobin targets, and the role of supplemental oxygen for treatment of suspected postoperative ischemia.

Relative anemia and perioperative stroke in children with moyamoya

OBJECTIVES

Surgical revascularization for moyamoya arteriopathy decreases long-term stroke risk but carries a risk of perioperative ischemic complications. We aimed to evaluate modifiable stroke risk factors in children undergoing surgical revascularization for moyamoya.

MATERIALS AND METHODS

In this exploratory, single-center, retrospective cohort study, medical records of pediatric patients undergoing surgical revascularization for moyamoya arteriopathy at our center between 2003 and 2021 were reviewed. Candidate modifiable risk factors were analyzed for association with perioperative stroke, defined as ischemic stroke ≤7 days after surgery.

RESULTS

We analyzed 53 surgeries, consisting of 39 individual patients undergoing indirect surgical revascularization of 74 hemispheres. Perioperative ischemic stroke occurred following five surgeries (9.4%). There were no instances of hemorrhagic stroke. Larger pre-to-postoperative decreases in hemoglobin (OR 3.90, p=0.017), hematocrit (OR 1.69, p=0.012) and blood urea nitrogen (OR 1.83, p=0.010) were associated with increased risk of perioperative ischemic stroke. Weight-adjusted intraoperative blood loss was not associated with risk of perioperative ischemic stroke (OR 0.94, p=0.796). Among children with sickle cell disease, all of whom underwent exchange transfusion within one week prior to surgery, none experienced perioperative stroke.

CONCLUSIONS

Decreases in hemoglobin, hematocrit, and blood urea nitrogen between the preoperative and postoperative periods are associated with increased risk of perioperative stroke. These novel findings suggest that dilutional anemia, possibly due to standardly administered hyperhydration, may increase the risk of perioperative stroke in some children with moyamoya. Further work optimizing both mean arterial pressure and oxygen-carrying capacity in these patients, including consideration of alternative blood transfusion thresholds, is necessary.

Nomogram for Predicting Long-term Outcomes of Encephaloduroarteriosynangiosis in Toddlers with Moyamoya Disease: a Longitudinal and Cross-sectional Study

We investigated the long-term outcomes of encephaloduroarteriosynangiosis (EDAS) for stroke prevention in toddlers with moyamoya disease (MMD) using nomogram. Between January 2005 and December 2018, 74 toddlers with MMD underwent surgery in the Fifth Medical Centre, Chinese PLA General Hospital, 69 were < 4 years of age and included in the analysis. The modified Rankin scale (mRS) during follow-up evaluated clinical outcomes. To measure the effectiveness of EDAS, the annual risk of symptomatic infarction within the operated brain hemispheres was calculated. The event-free survival rate was determined using Kaplan-Meier curves. A nomogram generated using multivariate logistic regression analysis identified potential predictors associated with unfavorable outcomes. Additionally, discrimination, calibration, and clinical utility were assessed. A favorable clinical outcome was observed in 81.2% of the patients. The operated hemispheres showed an annual risk of 0.87% of symptomatic infarction and 0.23% of hemorrhage. Moreover, the 10-year event-free survival rates were 92.8% and 97.0% for symptomatic infarction and hemorrhage. Multivariate logistic analysis indicated that onset with infarction, initial mRS ≥ 3, and perioperative adverse events had significant and independent associations with unfavorable outcomes. However, an age at diagnosis of ≥ 2 years showed an association with favorable outcomes. Using these four factors, our model attained a concordance index of 0.912 (95% confidence interval, 0.842-0.982), well-fitted calibration curve, and cutoff value of 0.212 for predicting unfavorable outcomes. EDAS may prevent recurrent stroke and improve overall long-term clinical outcomes in toddlers with MMD. The developed nomogram accurately predicted unfavorable outcomes and assisted surgeons in patient evaluation.

Effect of newly developed scissors-attached micro-forceps on the recipient clamp time and occurrence of anastomotic site infarction after bypass surgery for moyamoya disease

Introduction

This study aimed to examine the effect of newly developed scissors-attached micro-forceps in superficial temporal artery-to-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease (MMD).

Materials and methods

Of 179 consecutive STA-MCA anastomoses on 95 hemispheres of 71 MMD patients at the University of Fukui Hospital between 2009 and 2023, 49 anastomoses on 26 hemispheres of 21 patients were enrolled in this retrospective cohort clinical trial intraoperative indocyanine green video-angiography did not demonstrate bypass patency in three anastomoses in two patients who were excluded. Twenty-one anastomosis in 19 hemispheres of 16 patients were performed using the conventional micro-forceps (conventional group, CG), and 25 anastomoses in 22 hemispheres of 19 patients were performed using scissors-attached micro-forceps (scissors group, SG). A small infarction near the anastomotic site detected using postoperative diffusion-weighted imaging was defined as anastomotic site infarction (ASI). Factors affecting the occurrence of ASI were examined by univariate, logistic regression, and receiver operating curve (ROC) analysis.

Results

There were no significant differences in clinical parameters such as age, sex, number of sacrificed branches, number of sacrificed large branches, and number of sutures between the CG and SG. However, the clamp time and occurrence of ASI were significantly lower in the SG than in the CG. Logistic regression analysis revealed that the clamp time was the only significant factor predicting the occurrence of ASI. A receiver operating curve analysis also revealed that the clamp time significantly predicted the occurrence of ASI (area under the curve, 0.875; cutoff value, 33.2 min).

Conclusion

The newly developed scissors-attached micro-forceps could significantly reduce the clamp time and occurrence of ASI in STA-MCA anastomosis for MMD.

Perioperative Management of Pediatric Patients with Moyamoya Arteriopathy

Pediatric patients with moyamoya arteriopathy are at high risk for developing new onset transient or permanent neurologic deficits secondary to cerebral hypoperfusion, particularly in the perioperative period. It is therefore essential to carefully manage these patients in a multidisciplinary, coordinated effort to reduce the risk of new permanent neurologic deficits. However, little has been published on perioperative management of pediatric patients with moyamoya, particularly in the early postoperative period during intensive care unit admission. Our pediatric neurocritical care team sought to create a multidisciplinary periprocedural evidence- and consensus-based care pathway for high-risk pediatric patients with moyamoya arteriopathy undergoing anesthesia for any reason to decrease the incidence of periprocedural stroke or transient ischemic attack (TIA). We reviewed the literature to identify risk factors associated with perioperative stroke or TIA among patients with moyamoya and to gather data supporting specific perioperative management strategies. A multidisciplinary team from pediatric anesthesia, neurocritical care, nursing, child life, neurosurgery, interventional neuroradiology, neurology, and hematology created a care pathway for children with moyamoya undergoing anesthesia, classifying them as either high or standard risk, and applying an individualized perioperative management plan to high-risk patients. The incidence of neurologic sequelae before and after pathway implementation will be compared in future studies.

Indirect Bypass With Pericranial Transposition for Moyamoya Syndrome in an Infant

Moyamoya syndrome (MMS) is a progressive disease that can result in debilitating strokes. Surgical revascularization is the mainstay of treatment. Selection of the proper bypass technique depends on the vascular anatomy and location of the hypoperfused cerebral territory. We describe here a case of successful indirect bypass utilizing a pericranial flap as well as dural inversion. A seven-month-old female was transferred from an outside facility to our institution for further evaluation and surgical treatment of MMS. She presented with bilateral brain infarcts worse on the left, with right-sided body weakness. After medical stabilization and hyperhydration, she was taken to the operating room for a left-sided indirect bypass. The superficial temporal artery (STA) was traced utilizing doppler but was determined to be too diminutive for transposition, so the decision was made to proceed with encephalo-duro-pericranio-synangiosis (EDPS). A pericranial graft was successfully affixed to the cortical surface in the hypoperfused middle cerebral artery (MCA) territory, and the dura was inverted. Postoperatively, the patient developed a pseudomeningocele, so a revision surgery was performed. She was discharged shortly after this and returned for encephalo-duro-arterio-synangiosis (EDAS) of the contralateral side. She followed up three months after her initial bypass surgery at age 10 months and was crawling without any focal deficits. She was lost to follow-up thereafter. EDPS is a safe technique for infants with MMS whose STA is too diminutive to be used for bypass surgery. This may be an effective method for indirect bypass in these patients.

Risk Factors for Ischemic Stroke After Revascularization Surgery in Patients with Moyamoya Disease: An Age-Stratified Comparative Meta-Analysis

BACKGROUND

Patients who undergo revascularization surgery for moyamoya disease may develop postoperative ischemic stroke (pIS). Several studies have sought to identify risk factors; however, the findings remain highly inconsistent.

METHODS

PubMed, Scopus, and Web of Science were used to extract references. The first phase of screening required the studies to be in English, involve patients surgically treated for moyamoya disease, and report pIS. The second phase required the studies to provide ≥10 patients and include a control group.

RESULTS

All 22 studies were rated as high quality. Univariate analysis identified pediatrics <3 years of age as a risk factor for pIS (odds ratio [OR], 7.60; P < 0.0001). Among adult patients only, diabetes (OR, 2.10; P = 0.005), a Suzuki grade greater than 3 (OR, 1.74; P = 0.005), mean intraoperative systolic blood pressure (OR, 1.04; P < 0.0001), mean intraoperative diastolic blood pressure (OR, 1.04; P = 0.002), and revascularization in the left hemisphere (OR, 2.09; P = 0.001) were risk factors. Among both age groups, preoperative ischemic stroke (OR, 2.59; P < 0.00001) was a risk factor for pIS. Additionally, perioperative antiplatelet drug administration was a protective factor for specifically acute postoperative white thrombus among adult patients (OR, 0.35; P = 0.002).

CONCLUSIONS

In addition to the methods discussed that can mitigate the risk of pIS, the risk factors identified in our analysis may be of great value among surgeons for identifying high-risk patients in order to apply prophylactic measures, as well as scheduling longer and more frequent follow-up visits.

Risk factors and a novel cerebral infarction extent scoring system for postoperative cerebral ischemia in patients with ischemic Moyamoya disease

Postoperative cerebral ischemic complication is the most common complication of revascularization surgery for patients with moyamoya disease (MMD). This retrospective study was conducted on 63 patients with ischemic MMD. Postoperative ischemia occurred in 15 of the 70 revascularization operations performed for patients after surgical revascularization, translating to an incidence of 21.4%. Univariate analysis revealed that onset infarction (p = 0.015), posterior cerebral artery involvement (p = 0.039), strict perioperative management (p = 0.001), interval time between transient ischemic attack (TIA) or infarction presentation and operation (p = 0.002) and preoperatively cerebral infarction extent score (CIES) (p = 0.002) were significantly associated with postoperative cerebral ischemia. Multivariate analysis revealed that strict perioperative management (OR = 0.163; p = 0.047), and preoperatively CIES (OR = 1.505; p = 0.006) were independently associated with postoperative cerebral ischemia-related complications. After comprehensive improvement of perioperative management protocol, the incidence of symptomatic infarction declined to 7.4% (4 out of 54). Analysis of the area under the receiver operating characteristic curve (AUROC) indicated CIES was a predictor for both postoperative ischemia and high follow-up modified Rankin Scale scores. In summary, strict perioperative management and CIES were identified as independent risk factors for postoperative ischemic complications in ischemic MMD, demonstrating that comprehensive and individualized perioperative management improve postoperative outcomes in patients with MMD. Furthermore, application of CIES to evaluate pre-existing cerebral infarction can improve the management of patients.

European Stroke Organisation (ESO) Guidelines on Moyamoya angiopathy: Endorsed by Vascular European Reference Network (VASCERN)

The European Stroke Organisation (ESO) guidelines on Moyamoya Angiopathy (MMA), developed according to ESO standard operating procedure and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology, were compiled to assist clinicians in managing patients with MMA in their decision making. A working group involving neurologists, neurosurgeons, a geneticist and methodologists identified nine relevant clinical questions, performed systematic literature reviews and, whenever possible, meta-analyses. Quality assessment of the available evidence was made with specific recommendations. In the absence of sufficient evidence to provide recommendations, Expert Consensus Statements were formulated. Based on low quality evidence from one RCT, we recommend direct bypass surgery in adult patients with haemorrhagic presentation. For ischaemic adult patients and children, we suggest revascularization surgery using direct or combined technique rather than indirect, in the presence of haemodynamic impairment and with an interval of 6–12 weeks between the last cerebrovascular event and surgery. In the absence of robust trial, an Expert Consensus was reached recommending long-term antiplatelet therapy in non-haemorrhagic MMA, as it may reduce risk of embolic stroke. We also agreed on the utility of performing pre- and post- operative haemodynamic and posterior cerebral artery assessment. There were insufficient data to recommend systematic variant screening of RNF213 p.R4810K. Additionally, we suggest that long-term MMA neuroimaging follow up may guide therapeutic decision making by assessing the disease progression. We believe that this guideline, which is the first comprehensive European guideline on MMA management using GRADE methods will assist clinicians to choose the most effective management strategy for MMA.

Risk Factors and Imaging Biomarkers Associated With Perioperative Stroke in Pediatric Moyamoya Arteriopathy

Patients with moyamoya arteriopathy are at high risk for developing ischemic stroke in the perioperative period. We sought to evaluate whether preoperative clinical and neuroimaging biomarkers are associated with postoperative stroke and transient ischemic attack in children with moyamoya following revascularization surgery. We performed a retrospective chart review of pediatric patients who underwent revascularization surgery for moyamoya in the last 15 years. Fifty-three patients who underwent 69 surgeries met the inclusion criteria. We recorded clinical predictors of stroke or transient ischemic attack within 7 days following surgery. We used Suzuki stage and Composite Cerebrovascular Stenosis Score to analyze neuroimaging. Significant risk factors for developing postoperative stroke or transient ischemic attack were younger age at surgery (P = .004) and transient ischemic attack less than 1 month prior to surgery (P < .001). Children under 5 and those with recent preoperative ischemic events should be the focus of investigation to evaluate modifiable risk factors and targeted interventions.

The preoperative focal cerebral blood flow status may be associated with slow flow in the bypass graft after combined surgery for moyamoya disease

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.

The usefulness and safety of dexmedetomidine for postoperative sedation in pediatric patients with moyamoya disease

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.

Symptomatic hyperperfusion after combined revascularization surgery in patients with pediatric moyamoya disease: patient series

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.

Risk Factors for Cerebral Infarction Early After Revascularization in Children Younger than 5 Years with Moyamoya Disease

OBJECTIVE

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Spatially separate cerebral infarction in the posterior cerebral artery territory after combined revascularization of the middle cerebral artery territory in an adult patient with moyamoya disease and fetal-type posterior communicating artery: illustrative case

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.

Cerebral Ischemic Complications After Surgical Revascularization for Moyamoya Disease: Risk Factors and Development of a Predictive Model Based on Preoperative Nutritional Blood Parameters

Objectives

Cerebral ischemic complications are common after revascularization in patients with moyamoya disease (MMD). Risk factors from specific laboratory variables have only been assessed by limited research. This study was to investigate the association between postoperative cerebral ischemia and nutritional blood parameters and examine predictive values of such risk factors in adults.

Methods

Preoperative demographics and nutritional blood parameters of patients with MMD who received revascularization at our institution from 2012 to 2021 were retrospectively reviewed. Univariate analysis and multivariable logistic regression were used to identify independent risk factors for the onset of postoperative cerebral ischemic complications. Predictive values were tested and a model incorporating these independent risk factors was created using the R program. Area under the receiver operating characteristic curve (AUC) was used for testing its discriminability.

Results

Postoperative cerebral ischemic complications occurred in 32 patients of 100 included procedures. Surgery on the left hemisphere, lower admission modified Rankin Scale (mRS) score, aberrant nutritional parameters including low white blood cell (WBC), and high total cholesterol (TC) were significantly associated with cerebral ischemic complications after revascularization. The intriguing role of WBC might be explained by altered immunomodulation. The AUC of this model with novel nutritional parameters yielded a value of 0.811, presenting better predictive accuracy. Additionally, the model was visualized in the form of a nomogram and translated into a user-friendly calculator to generate individual risk.

Conclusions

Surgical side, admission mRS score, WBC, and TC were independent risk factors for postoperative cerebral ischemic complications. The model composed of these four parameters was promising to be adopted in clinical practice.

Paradoxical symptomatic cerebral blood flow decreases after combined revascularization surgery for patients with pediatric moyamoya disease: illustrative case

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.

Challenging direct bypass surgery for very young children with moyamoya disease: technical notes

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.

Distinct Clinical and Radiographic Phenotypes in Pediatric Patients With Moyamoya

BACKGROUND

Given the expanding evidence of clinico-radiological differences between moyamoya disease (MMD) and moyamoya syndrome (MMS), we compared the clinical and radiographic features of childhood MMD and MMS to identify predictors of ischemic event recurrence.

METHODS

We reviewed a pediatric moyamoya cohort followed between 2003 and 2019. Clinical and radiographic characteristics at diagnosis and follow-up were abstracted. Comparisons between MMD and MMS as well as between MMD and two MMS subgroups (neurofibromatosis [MMS-NF1] and sickle cell disease [MMS-SCD]) were performed.

RESULTS

A total of 111 patients were identified. Patients with MMD presented commonly with transient ischemic attacks (TIAs) (35 % MMD versus 13% MMS-NF1 versus 9.5% MMS-SCD; P = 0.047). Symptomatic stroke presentation (MMD 37% versus MMS-NF1 4% versus 33%; P = 0.0147) and bilateral disease at diagnosis (MMD 73% versus MMS-NF1 22 % versus MMS-SCD 67%; P = 0.0002) were uncommon in MMS-NF1. TIA recurrence was common in MMD (hazard ratio 2.86; P = 0.001). The ivy sign was absent on neuroimaging in a majority of patients with MMS-SCD (MMD 67% versus MMS-NF1 52% versus MMS-SCD 9.5%; P = 0.0002). Predictors of poor motor outcome included early age at diagnosis (odds ratio [OR] 8.45; P = 0.0014), symptomatic stroke presentation (OR 6.6; P = 0.019), and advanced Suzuki stage (OR 3.59; P = 0.019).

CONCLUSIONS

Moyamoya exhibits different phenotypes based on underlying etiologies. Frequent TIAs is a common phenotype of MMD and symptomatic stroke presentation a common feature of MMD and MMS-SCD, whereas unilateral disease and low infarct burden are common in MMS-NF1. In addition, absence of ivy sign is a common phenotype in MMS-SCD.

Risk factors for postoperative ischemic complications in pediatric moyamoya disease

Background

Ischemic events are the most common postoperative complication in bypass surgery for moyamoya disease (MMD), but the risk factors for pediatric MMD remain unclear. The goal of the study was to investigate the risk factors for postoperative ischemic complications in pediatric MMD patients.

Methods

We retrospectively reviewed a consecutive series of pediatric MMD cases at Beijing Tiantan Hospital, Capital Medical University from June 2010 through June 2019. Preoperative clinical variables and radiographic findings were recorded, and logistic regression analysis was carried out to identify the risk factors for postoperative ischemic events.

Results

A total of 533 operations in 336 patients were included in this study. Postoperative complications occurred after 51 operations (9.6%), including 40/447 indirect bypass procedures, 9/70 direct bypass procedures, and 2/16 combined bypass procedures. Postoperative ischemic events were the most common complication and occurred in 30 patients after 31 procedures (8.9% per patient; 5.8% per operation), including 26/447 indirect bypass procedures, 4/70 direct bypass procedures, and 1/16 combined bypass procedures, and the incidence of these events did not differ significantly between indirect and non-indirect bypass (5.8% vs 5.8%; p = 0.999). Multivariate logistic regression analyses revealed that older age at operation (OR 1.129, 95% CI 1.011–1.260, p = 0.032) and posterior cerebral artery involvement (OR 2.587, 95% CI 1.030–6.496, p = 0.043) were significantly associated with postoperative ischemic events.

Conclusion

We speculate that older age at operation and posterior cerebral artery involvement are risk factors for postoperative ischemic events in pediatric MMD patients.

Specific clinical features and one-stage revascularization surgery for moyamoya disease with severe cerebral ischemia in the territory of posterior cerebral artery

BACKGROUND

There are no reports describing the surgical procedure for moyamoya disease (MMD) patients with severe cerebral ischemia in the territory of the posterior cerebral artery (PCA) at initial presentation. In this study, therefore, we describe their clinical and radiological features and clinical results of one-stage revascularization surgery for both anterior and posterior circulation.

METHODS

This study included 6 MMD patients who had severe cerebral ischemia in the PCA territory and underwent one-stage revascularization surgery for both anterior and posterior circulation. Of these, one patient underwent it on both sides. Their clinical and radiological data were precisely analyzed. Compared with usual procedure, craniotomy was extended towards the temporo-parietal area more widely. The parietal branch of superficial temporal artery (STA) was anastomosed to the angular or posterior temporal artery, while the frontal branch was anastomosed to the frontal branch of MCA. Ultimate indirect bypass was added. Their clinical and radiological outcomes were evaluated.

RESULTS

Their neurological symptoms included visual and speech disturbance as well as numbness of the extremities. Cerebral infarct was distributed in the posterior temporal, parietal, and/or occipital lobe. Cerebral hemodynamics and metabolism were also impaired in the same regions. These findings were completely different from those in MMD patients without PCA lesion. Postoperative course was uneventful, and none of them recurred stroke during a mean follow-up period of 10.5 years. Surgical collaterals widely provided blood flow to the entire hemispheres, including the occipital lobe. Cerebral hemodynamics and metabolism markedly improved after surgery.

CONCLUSION

One-stage revascularization surgery for both anterior and posterior circulation is feasible and effective to prevent future stroke in MMD patients with severe cerebral ischemia in the PCA territory at initial presentation.

Postoperative stroke and neurological outcomes in the early phase after revascularization surgeries for moyamoya disease: an age-stratified comparative analysis

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.

Clinical outcomes after revascularization for pediatric moyamoya disease and syndrome: A single-center series

Moyamoya is a progressive cerebrovascular arteriopathy that affects children of any age. The goal of this study was to determine imaging and clinical outcomes as well as complication rates in a pediatric cohort undergoing either a combined direct/indirect or indirect-only revascularization approach. Patients with moyamoya disease or syndrome ≤ 18 years of age at the time of initial surgery were identified, and clinical data were collected retrospectively. Over a 12-year period, 26 patients underwent revascularization procedures on 49 hemispheres with a median follow-up of 2.6 years from surgery. Median age at surgery was 7.3 years (range 1.4-18.0 years). Thirty-three hemispheres (67.3%) underwent combined revascularization with a direct bypass and encephalomyosynangiosis, and sixteen hemispheres (32.7%) underwent indirect-only revascularization. The rate of 30-day perioperative complication was 10.2%, and the rate of postoperative clinical stroke by end of follow-up was 10.2% by hemisphere. There was a 5.7% rate of intraoperative bypass failure requiring conversion to an indirect revascularization approach. On follow-up imaging, 96.9% of direct bypasses remained patent. On multivariate analysis, higher preoperative Pediatric Stroke Outcome Measure (PSOM) scores were associated with lower rates of good clinical outcome on follow-up (unit OR 0.03; p = 0.03). Patients with age < 5.4 years had lower rates of good clinical outcome on follow-up. In this North American cohort, both combined direct/indirect and indirect only revascularization techniques were feasible. However, younger children < 5.4 years of age have worse outcomes than older children, similar to east Asian cohorts.

Mechanical thrombectomy for a 12-year-old boy with acute ischemic stroke: A case report

RATIONALE

Acute ischemic stroke (AIS) is one of the most severe diseases that endanger human health. It is very common among middle-aged and elderly people, but it is rare in children. The treatment varies among children and adults, since the cause for AIS in children differs from that in adults. In adults with AIS, endovascular therapy has been recommended, but guidelines for endovascular therapy in children with AIS have not been established yet. In China, few relevant evidence is present so far in clinical research of mechanical thrombectomy in the treatment for children with AIS.

PATIENT CONCERNS

A 12-year-old boy without any special physical collision and trauma was admitted to emergency department of Changsha central hospital due to hemiplegia of left limbs for 3 hours.

DIAGNOSES

He was diagnosed with AIS after magnetic resonance imaging (MRI) examination and magnetic resonance angiography (MRA) examination. Cerebral infarction in the right parietal, temporal, insular, and frontal lobes was revealed by the MRI test. The MRA test detected occlusions in right internal carotid artery, A1 segment of right anterior cerebral artery, right middle cerebral artery, and distal branch.

INTERVENTIONS

Mechanic thrombectomy and antiplatelet aggregation therapy with clopidogrel helped the patient to recover, along with active rehabilitation training.

OUTCOMES

A significant improvement in muscle strength of his left limbs was proved. He walked by himself and had 2 of Modified Rankin Scale (MRS). At 1-year follow-up visit, he recovered well except feeling a bit pain of left lower limb when walking, with finally MRS of 1.

CONCLUSIONS

Mechanical thrombectomy can be performed safely for children with AIS, but needs a further research with large samples.

Association Between Ghrelin Gene Polymorphism and Cerebral Infarction

Background

The aim of this study was to explore the associations of ghrelin gene polymorphisms at rs26312, rs26802 and rs27647 with cerebral infarction.

Material/Methods

A total of 200 cerebral infarction patients in our hospital were enrolled as the disease group, while 200 healthy people were enrolled as the control group. Peripheral venous blood was collected from both groups, and the ghrelin gene polymorphisms at rs26312, rs26802, and rs27647 in nucleated cells were detected through sequencing.

Results

The genotype distribution at ghrelin gene loci rs26802 and rs27647 in the disease group was significantly different from that in the control group. The distribution of recessive model at ghrelin gene locus rs26802 in the disease group was different from that in the control group, in which the TG+GG frequency was evidently higher in the disease group. The AA genotype at ghrelin gene locus rs26312 was remarkably associated with the ghrelin gene expression level, and the expression level of ghrelin gene in the disease group was remarkably lower than that in the control group. The genotype at ghrelin gene locus rs26312 was associated with activated partial thromboplastin time (APTT), and APTT was significantly shorter in patients with GG genotype. The genotype at ghrelin gene locus rs26802 was associated with D-dimer, and the D-dimer level was significantly lower in patients with TG genotype. The genotype at ghrelin gene locus rs27647 was associated with prothrombin time (PT), and PT was obviously shorter in patients with TT genotype.

Conclusions

The ghrelin gene polymorphisms are remarkably associated with the occurrence of cerebral infarction.

Large Craniotomy Increases the Risk of Minor Perioperative Complications in Revascularization Surgery for Moyamoya Disease

OBJECTIVE

Larger craniotomy is expected to increase blood flow over a wider range after indirect revascularization. However, the optimal size of craniotomy has not been established. In this study perioperative complications in revascularization surgery for moyamoya disease are evaluated, focusing on craniotomy size.

METHODS

We retrospectively analyzed 87 hemispheres in 65 patients with moyamoya disease who had undergone revascularization surgery. Areas and types of craniotomy were classified as 1-piece craniotomy in the middle cerebral artery (MCA) territory (1-piece group) in 54 hemispheres (mean area of craniotomy, 40.6 ± 13.5 cm²); 2-piece craniotomy in the MCA territory with anterior cerebral artery (ACA) territory (2-piece group) in 16 hemispheres (mean area of craniotomy, 55.4 ± 12.0 cm²); and 1-piece craniotomy in both MCA and ACA territories (large group) in 17 hemispheres (mean area of craniotomy, 84.2 ± 11.0 cm²). Perioperative complication rates in each craniotomy group were analyzed.

RESULTS

Perioperative complications occurred in 45 hemispheres (52%). Transient, moderate, and severe complications occurred in 38 hemispheres, 3 hemispheres, and 4 hemispheres, respectively. Complication rates in the 1-piece, 2-piece, and large groups were 41%, 63%, and 76%, respectively. Large craniotomy was associated with a significantly higher frequency of complications (P = 0.01). However, no significant difference was found among groups when limiting analysis to moderate and severe complications. Multivariate analysis showed large craniotomy as the only factor independently related to complications (odds ratio, 2.93; 95% confidence interval, 1.08-7.92; P = 0.034).

CONCLUSIONS

Large craniotomy is associated with more frequent perioperative complications, especially transient symptoms.

Surgical outcomes for pediatric moyamoya: a systematic review and meta-analysis

OBJECTIVE

The optimal revascularization for pediatric moyamoya for reducing the incidence of future stroke events remains to be determined.

METHODS

The authors conducted a search of PubMed, MEDLINE, Embase, and Web of Science electronic databases from inception until January 2019. The primary endpoint was the presence of a future ischemic stroke event. Secondary endpoints were angiographic outcomes as measured by postoperative Matsushima grade and clinical symptom persistence. Patients who underwent either direct or combined direct/indirect revascularization were classified into the direct cohort. Data from each study on presence of postoperative stroke events were used to generate standardized mean differences and 95% confidence intervals, which were combined using inverse variance-weighted averages of standardized mean differences in a random effects model.

RESULTS

Twenty-nine studies met the inclusion criteria for analysis, comprising 2258 patients (1011 males, mean age 8.3 ± 1.8 years) who were followed up clinically for an average of 71.4 ± 51.3 months. One hundred fifty-four patients underwent direct bypass alone, 680 patients underwent either direct or combined direct/indirect revascularization procedures, while 1424 patients underwent indirect bypass alone. The frequencies of future stroke events in patients undergoing direct bypass alone, combined bypass, or indirect bypass alone were 1 per 190.3 patient-years, 1 per 108.9 patient-years, and 1 per 61.1 patient-years, respectively, in each cohort. The estimated stroke rates were 9.0% with indirect revascularization, 4.5% with direct revascularization alone, and 6.0% with combined revascularization. A forest plot did not reveal any significant differences in the incidence of future stroke events or angiographic outcomes following direct-only, combined, or indirect-only revascularization.

CONCLUSIONS

Direct, indirect, and combined indirect/direct bypass techniques are all effective revascularization options for pediatric moyamoya disease. A relative paucity of granular studies-and inherent surgical selection bias-limits direct comparison between interventions. Suitably designed prospective cohort studies may be useful in identifying patients likely to receive benefit from specific procedures.

Dexmedetomidine Attenuates Neuroinflammatory-Induced Apoptosis after Traumatic Brain Injury via Nrf2 signaling pathway

Objective

Dexmedetomidine (DEX) exhibits neuroprotective effects as a multifunctional neuroprotective agent in numerous neurological disorders. However, in traumatic brain injury (TBI), the molecular mechanisms of these neuroprotective effects remain unclear. The present study investigated whether DEX, which has been reported to exert protective effects against TBI, could attenuate neuroinflammatory‐induced apoptosis and clarified the underlying mechanisms.

Methods

A weight‐drop model was established, and DEX was intraperitoneally injected 30 min after inducing TBI in rats. The water content in the brain tissue was measured. Terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling (TUNEL) assays were performed on histopathological tissue sections to evaluate neuronal apoptosis. Enzyme‐linked immunosorbent assay and PCR were applied to detect the levels of the inflammatory factors, TNF‐α, IL‐1β, IL‐6, and NF‐κB.

Results

TBI–challenged rats exhibited significant neuronal apoptosis, which was characterized via the wet‐to‐dry weight ratio, neurobehavioral functions, TUNEL assay results and the levels of cleaved caspase‐3, Bax upregulation and Bcl‐2, which were attenuated by DEX. Western blot, immunohistochemistry, and PCR results revealed that DEX promoted Nrf2 expression and upregulated expression of the Nrf2 downstream factors, HO‐1 and NQO‐1. Furthermore, DEX treatment markedly prevented the downregulation of inflammatory response factors, TNF‐α, IL‐1β and NF‐κB, and IL‐6.

Interpretation

Administering DEX attenuated inflammation‐induced brain injury in a TBI model, potentially via the Nrf2 signaling pathway.

Preservation of the Arachnoid Membrane During Encephaloduroarteriosynangiosis Reduces Postoperative Complications without Undermining the Surgical Outcome in Pediatric Moyamoya Disease

BACKGROUND

Encephaloduroarteriosynangiosis (EDAS) is a commonly used indirect revascularization operation method to treat pediatric patients with Moyamoya disease (MMD). Arachnoid dissection frequently has been performed during the EDAS operation to promote better revascularization. However, no studies have yet proven its surgical benefits. In this study, we investigated the impact of arachnoid preservation on the surgical outcome and postoperative complication by comparing pediatric patients with MMD who had the arachnoid membrane preserved during EDAS operation with those who had it dissected.

METHODS

This was a retrospective cohort study based on a single surgeon's experience at a single institution. A total of 206 pediatric patients with MMD who underwent EDAS operation at Seoul National University Children's Hospital were recruited for the study. We compared the surgical outcome and the postoperation complication rate of these 2 groups. Furthermore, risk factors for postoperative complication were analyzed.

RESULTS

The overall clinical outcome (P = 0.342) and the extent of revascularization of middle cerebral artery territories (P = 0.736) were not different between the arachnoid dissection group and the arachnoid preservation group. However, the postoperative infarction/hemorrhage rate was significantly greater in the arachnoid dissection group (P = 0.005). Arachnoid dissection (P = 0.011) and young age (<3 years old, P = 0.012) were significantly associated with increased risk of postoperative complications.

CONCLUSIONS

Arachnoid preservation may help to reduce postoperative complications without decreasing the surgical outcome of EDAS. Furthermore, factors such as the patient's age should be taken into account when treating pediatric patients with MMD.