Surgical treatment of moyamoya disease in pediatric patients--comparison between the results of indirect and direct revascularization procedures

Tie2-expressing monocytes/macrophages promote angiogenesis in chronically ischaemic brain tissue

BACKGROUND

Over half of patients with chronically ischaemic cerebrovascular disease (CICD) exhibit poor revascularization potential. Tie2-expressing monocytes/macrophages (TEMs) have been reported to promote angiogenesis in tumour tissue; however, whether TEMs promote angiogenesis in chronically ischaemic brain tissue (CIBT) and the regulatory mechanism through which TEMs are recruited to CIBT remain unclear.

METHODS

We first analysed the proportion of TEMs in blood from the internal jugular veins (IJVs) of CICD patients and then isolated TEMs for coculture with human umbilical vein endothelial cells (HUVECs) and for intraventricular injection into nude mice to explore the proangiogenic effects of TEMs in CIBT. Then, molecular biology experiments were performed to verify the upstream regulatory mechanism of the ANGPT2-Tie2 axis, and cell transfection experiments were conducted to confirm the regulatory effects of the detected pathway on Tie2 receptors on the endothelial cell surface. Additionally, a 2-vessel occlusion plus encephalomyosynangiosis rat model was established to confirm the recruitment mechanism of TEMs in CIBT and their ability to improve cerebral blood perfusion (CBP) and cognitive function.

RESULTS

The proportion of TEMs from the IJV blood of CICD patients significantly increased, especially in patients who exhibited Matsushima Grade-A revascularization. The viability of HUVECs cocultured with TEMs was significantly increased, and CBP and the expression of CD31 in the CIBT of nude mice treated with TEMs were significantly increased. The above increases were positively correlated with the concentration of TEMs used for coculture and intraventricular injection. Moreover, molecular biology experiments indicated that miR-126-5p can directly bind to the 3'UTR of TRPS1 mRNA and that TRPS1 can directly bind to the promoter of Angpt2. HUVECs transfected with miR-126-5p mimics presented significantly decreased TRPS1 expression, a reduced pTie2/Tie2 ratio, increased ANGPT2 expression, and increased cell viability. Finally, significantly increased TEMs infiltration, downregulated TRPS1 expression, and upregulated ANGPT2, CD31, VEGFA, and IGF1 expression were detected in the CIBT of the rats transfected with the miR-126-5p agomir, accompanied by significant improvements in CBP and cognitive function.

CONCLUSIONS

TEMs promote angiogenesis in CIBT through a paracrine mechanism, and the recruitment of TEMs to CIBT is regulated by the miR-126-5p/TRPS1/ANGPT2 pathway.

Correlation between collateral compensation of the posterior cerebral artery on 5 T magnetic resonance imaging and clinical classifications in patients with Moyamoya angiopathy

PURPOSE

Various clinical classifications of Moyamoya angiopathy (MMA) have different characteristics of collateral compensation. Advancements in 5 T MRI have made it possible to non-invasively assess vascular collateralization using 4-dimensional MR angiography (4DMRA). The objective of this study is to analyze collateral compensation in MMA patients using 4DMRA and determine variations among different clinical classifications.

MATERIALS AND METHODS

Collateral compensation of posterior cerebral artery (PCA) to anterior circulation was evaluated using 4DMRA at 5 T MRI. After adjusting for confounding factors, multivariate analyses were conducted to compare the distribution of PCA collateral compensation among patients with different clinical classifications of MMA.

RESULTS

85 MMA patients were enrolled in the study. Among the 158 hemispheres evaluated, 100 were asymptomatic, 7 were hemorrhagic, 50 were ischemic, and 1 had a combination of hemorrhagic and ischemic stroke. Multivariate logistic regression analysis revealed a statistically significant difference in total PCA collateral compensation scores between asymptomatic and ischemic hemispheres (P < 0.001, 95% CI [0.614, 0.839]). Subgroup analysis revealed a clear distinction between asymptomatic hemispheres and ischemic hemispheres (P = 0.001, 95% CI [0.193, 0.677]) in terms of PCA compensation to middle cerebral artery through the parieto-occipital branch. However, no notable differences were observed in other compensation pathways.

CONCLUSION

The collateral compensation of PCA to the anterior circulation in MMA patients, assessed by 4DMRA at 5 T MRI, is significantly associated with ischemic MMA. The parieto-occipital branch may be the most important compensatory pathway. 4DMRA can potentially serve as a valuable tool for evaluating the risk of ischemic stroke in patients with MMA.

Treatment for moyamoya disease with hyperhomocysteinemia

This study aimed to investigate the impact of controlling serum homocysteine on improving surgical outcomes in patients with moyamoya disease (MMD) and hyperhomocysteinemia. In this prospective observational cohort study, 477 patients with MMD post-encephaloduroarteriosynangiosis are divided into the HHcy-MMD post-control group (n = 193), HHcy-MMD uncontrolled group (n = 91), and MMD group (n = 193), with the HHcy-MMD post-control group further subdivided into good (homocysteine 0-10 μmol/L, n = 121) and general (homocysteine 10-15 μmol/L, n = 72) control groups. The differences in imaging and long-term clinical prognosis among the three groups were compared. No significant differences were noted in the Matsushima grade after encephaloduroarteriosynangiosis between the MMD group and HHcy-MMD post-control group (P > 0.05); however, there was a significant difference between the HHcy-MMD post-control group and HHcy-MMD uncontrolled group (P < 0.001). A significant difference was noted between the good and general control groups in the Matsushima grade (P = 0.025) and long-term follow-up clinical outcomes (P = 0.035). The area under the curve of homocysteine levels for predicting adverse clinical outcomes was 85.48% (95% confidence interval: 80.31-90.65%). Effective control of serum Hcy level after EDAS surgery in Moyamoya disease patients with HHcy may lead to better prognosis.Clinical Trial Registration: This study was registered at ClinicalTrials.gov (NCT03613701).

Clinical Outcome and Surgical Outcome of Moyamoya Disease after Combined Revascularization Performed at the Neurological Institute of Thailand

Objective  Moyamoya disease is a chronic, progressive, intracranial steno-occlusive disease. Cerebral revascularization has proved that it is more beneficial than medical therapy for prevention of recurrent stroke. We aimed to report clinical and surgical outcome of moyamoya disease after combined revascularization in Thai population. Materials and Methods  From October 2015 to March 2023, patients diagnosed with moyamoya disease and were operated with combined revascularization were included. Patients were evaluated for hemodynamic state with preoperative and postoperative blood oxygenation level-dependent magnetic resonance (BOLD MR) imaging. Demographic data, serial imaging, surgical outcome, and clinical outcome were analyzed. Morbidity and mortality rates of surgery were reported. For clinical outcome evaluation, modified Rankin Scale (mRS) scores were compared between preoperative and postoperative outcome. The mRS score of 0 to 2 signify good outcome after surgery. Results  There were a total of 55 patients. Ischemic stroke was the most common presentation (87.3%). Based on the Suzuki's classification, most of the patients were stage 3 and 4. Clinical outcome measured with mRS score had good outcome, 100% (mRS score 0-2). For surgical outcome, overall graft patency was 94.8%, overall complication rate was 6.5%, and mortality rate was zero. Mean follow-up duration was 44.5 ± 25.1 months. Recurrent stroke occurred in 1.3%, which was recurrent ischemic stroke. Conclusion  Combined revascularization in moyamoya disease in the Thai population has a good clinical outcome, an acceptable risk of complication, and a reduced recurrent rate of stroke. Clinical and surgical outcome should be studied in the long term with the use of BOLD MR with carbon dioxide stimuli for the evaluation of cerebral blood flow in the patient.

Multi-parameter MRI-Based Machine Learning Model to Evaluate the Efficacy of STA-MCA Bypass Surgery for Moyamoya Disease: A Pilot Study

Superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery represents the primary treatment for Moyamoya disease (MMD), with its efficacy contingent upon collateral vessel development. This study aimed to develop and validate a machine learning (ML) model for the non-invasive assessment of STA-MCA bypass surgery efficacy in MMD. This study enrolled 118 MMD patients undergoing STA-MCA bypass surgery. Clinical features were screened to construct a clinical model. MRI features were extracted from the middle cerebral artery supply area using 3D Slicer and employed to build five ML models using logistic regression algorithm. The combined model was developed by integrating the radiomics score (Rad-score) with the clinical features. Model performance validation was conducted using ROC curves. Platelet count (PLT) was identified as a significant clinical feature for constructing the clinical model. A total of 3404 features (851 × 4) were extracted, and 15 optimal features were selected from each MRI sequence as predictive factors. Multivariable logistic regression identified PLT and Rad-score as independent parameters used for constructing the combined model. In the testing set, the AUC of the T1WI ML model [0.84 (95% CI, 0.70-0.97)] was higher than that of the clinical model [0.66 (95% CI, 0.46-0.86)] and the combined model [0.80 (95% CI, 0.66-0.95)]. The T1WI ML model can be used to assess the postoperative efficacy of STA-MCA bypass surgery for MMD.

Enhanced Benefit of STA-MCA Bypass Surgery in Chronic Terminal Internal Carotid and/or Middle Cerebral Artery Occlusion Patients With Impaired Collateral Circulation: Introducing a Novel Assessment Approach for Collateral Compensation

Background: Ischemic stroke is one of the major emergency diseases leading to death and disability worldwide, characterized by its acute onset and the urgent need for prompt medical intervention to reduce mortality and long-term disability. Chronic terminal internal carotid artery and/or middle cerebral artery occlusion (CTI/MCAO) is an important subtype of intracranial artery occlusive disease. The superficial temporal artery-to-MCA (STA-MCA) bypass has been proposed to improve cerebral blood flow (CBF) and cerebrovascular reserve (CVR), potentially enhancing neurological outcomes. However, its safety and efficacy in CTI/MCAO patients remain controversial. Methods: A total of 107 CTI/MCAO patients from Nanjing Brain Hospital, enrolled between July 2019 and June 2022, were divided into surgical and medical treatment groups. Cerebral perfusion and collateral formation were evaluated using pseudocontinuous arterial spin labeling (pCASL) and digital subtraction angiography (DSA). Modified Rankin scale (mRS) score and complication rates were compared between the two groups. In addition, correlations between Matsushima grades, early-arriving flow proportion (EFP), and lesion-side cerebrovascular (LCBV) scores were analyzed. Results: The surgical group showed significantly lower mRS scores than the medical group (p=0.018), with no significant differences in complication rates at the 6-month follow-up (p=0.861). CBF differed significantly among affected MCA segments (p < 0.001), particularly in the insular and opercular regions (M2-M3) (p=0.006). Matsushima grades in unilateral CTI/MCAO patients were negatively correlated with preoperative LCBV scores (γ s = -0.468, p=0.005) and EFP (γ s = -0.648, p=0.007). EFP demonstrated high accuracy in predicting LCBV scores in CTI/MCAO patients (AUC = 0.902, p=0.004). Conclusion: STA-MCA bypass surgery improved neurological outcomes in CTI/MCAO patients, particularly those with poor preoperative collateral compensation. EFP may serve as a reliable, noninvasive tool for assessing collateral circulation status in this population.

Impact of RNF213 p.R4810K variant on postoperative temporal muscle swelling used in encephalo-myo-synangiosis after combined revascularization for Moyamoya disease

Postoperative neurological deterioration due to brain compression by the swollen temporal muscle pedicle used in encephalo-myo-synangiosis (EMS) is a potential complication of combined revascularization for Moyamoya disease (MMD). However, the factors contributing to this phenomenon remain poorly understood. This study aimed to identify factors associated with postoperative temporal muscle swelling following combined revascularization. A total of 37 consecutive combined revascularization using temporal muscle pedicle performed between 2021 and 2023 were analyzed. Postoperative temporal muscle volume was measured through serial CT scans on postoperative days (POD) 0, 1, 7, 14, and 30. Multiple regression analysis was performed to assess factors contributing to swelling, including RNF213 p.R4810K variant, a known genetic risk for Asian MMD. Surgical outcomes and collateral vessel development were also examined. Results showed a significant increase in muscle pedicle volume on POD 1 and 7 across all 37 hemispheres, followed by a marked decrease by POD 30, compared to POD 0. These chronological volume changes were significant in adults (n = 31) but not in pediatric patients (n = 6). Multiple regression analysis identified the RNF213 p.R4810K as sole significant factor positively associated with maximal muscle volume (regression coefficient 0.485, P = 0.0078). Favorable surgical outcomes were achieved in 36 of 37 cases (97.3%) over a mean follow-up of 2.2 years, with indirect collateral development confirmed in 27 adult (87%) and 6 pediatric (100%) hemispheres. Results suggest the RNF213 p.R4810K variant is associated with increased postoperative temporal muscle swelling after combined revascularization, especially in adult MMD patients, indicating a potential genetic influence on this complication.

Role of scalp arteries in revascularization after side to side anastomosis in moyamoya disease patients

In our recent study, we introduced a novel side-to-side (S-S) bypass technique for adult moyamoya disease (MMD) patients. We aimed to validate the potential of this technique in enhancing postoperative revascularization. Patients undergoing S-S or end-to-side (E-S) bypass were enrolled, clinical data and angiography parameters were collected and compared. We included 44 E-S and 40 S-S MMD patients. There were no significant differences in basic characteristics and postoperative Matsushima grades between the two groups. However, in the S-S group, fewer patients had Matsushima grade D (0%) compared to the E-S group (11.4%, P = 0.028). The S-S group showed a greater occipital artery (OA) participation in revascularization (87.5% vs. 56.8%, P = 0.002) and higher postoperative caliber change ratio (CCR) of the superficial temporal artery (STA)-frontal branch (1.26 ± 0.43 vs. 1.04 ± 0.53, P = 0.038) compared to the E-S group. This difference was more pronounced in the subgroup with poor revascularization outcomes: in the S-S group, the CCR of the STA-frontal branch and the degree of participation in revascularization were 1.163 ± 0.168 and 58.8%, respectively, while in the E-S group, they were only 0.798 ± 0.494 and 6.7%. The S-S group also had a higher OA CCR (1.133 ± 0.257) and participation (82.4%) compared to the E-S group (0.941 ± 0.216 and 37.5%, respectively). In conclusion, the S-S bypass technique effectively utilizes scalp arteries, particularly the STA-frontal branch and OA, for direct revascularization via the preserved distal STA in adult MMD patients. Scalp arteries can serve as a supplementary source of donor arteries, especially beneficial for patients with suboptimal revascularization outcomes.

Experience of an interdisciplinary management for pediatric Moyamoya disease: application of a novel Hemispheric Surgical Score

PURPOSE

The primary purpose of this study was to develop and implement a novel Hemispheric Surgical Score to guide the treatment of pediatric patients with Moyamoya disease (MMD). Additionally, we aimed to describe a comprehensive flowchart for the evaluation, treatment, and follow-up of these patients and to share our experience with the interdisciplinary management of a large pediatric cohort at a referral pediatric hospital.

METHODS

We conducted a retrospective observational study using medical records of patients diagnosed with MMD at the Pediatric Hospital "Prof. Dr. Juan P. Garrahan" in Buenos Aires, Argentina, from July 2013 to July 2023. From July 2016 onward, data were analyzed prospectively following the implementation of the Hemispheric Surgical Score and the flowchart. Evaluations included clinical, MRI, and angiographic criteria, and patients were managed by an interdisciplinary team. Demographic, clinical, and neuroimaging data were collected and analyzed.

RESULTS

Eighty hemispheres from 40 patients were analyzed, with cerebral revascularization performed on 72 hemispheres from 37 patients. The Hemispheric Surgical Score and flowchart standardized treatment decisions, and reduced the need for invasive studies like angiographies for follow-up. The majority of patients (79.1%) had favorable outcomes, with complete disease progression arrest and no worsening of imaging nor clinical scores during a median follow-up of 35.8 months.

CONCLUSION

The Hemispheric Surgical Score and the comprehensive flowchart have improved the management of MMD in pediatric patients by standardizing treatment and reducing unnecessary invasive procedures. This interdisciplinary approach has led to better patient outcomes, highlighting the need for further validation in larger studies and comparisons of different revascularization techniques through randomized clinical trials.

Association of retrograde bypass flow depth along cortical recipient arteries with revascularization outcomes in direct bypass surgery for Moyamoya disease

OBJECTIVE

During the cerebral digital subtraction angiography (DSA) follow-up after direct bypass surgery in patients with Moyamoya disease (MMD), we observed different depths of retrograde bypass flow along the original middle cerebral artery (MCA) pathway into the intracranial cavity through the anastomosed recipient vessels. The aim of this study was to investigate the relationship between these varying depths of retrograde bypass flow and the outcomes of revascularization.

METHODS

We conducted a retrospective study that included 109 patients (138 hemispheres) diagnosed with MMD and who underwent direct bypass surgery with subsequent DSA follow-up from 2022 to 2023. The study involved categorizing the retrograde flow of blood from superficial temporal artery (STA) into different segments of middle cerebral artery (MCA) as Retrograde Flow Level 1, Retrograde Flow Level 2, and Retrograde Flow Level 3, and correlating these definitions with the Matsushima grading system. We further investigated the correlation between the depth of retrograde bypass flow and fundamental patient characteristics, including sex, age, underlying medical conditions, side of surgery, preoperative diameter of the donor vessel STA, postoperative cerebral hemorrhage or infarction, and compensatory status of the middle meningeal artery and ophthalmic artery preoperatively.

RESULTS

Different retrograde flow levels were correlated with the Matsushima grading (P＜0.001), and preoperative diameter of the donor vessel STA was significantly larger in the Retrograde Flow Level 3 group compared to the Retrograde Flow Level 2 group.

CONCLUSIONS

The depth of retrograde flow in the recipient vessel MCA after direct bypass surgery for MMD was positively correlated with the Matsushima grading, which may serve as a novel method for evaluating the effectiveness of postoperative revascularization.

Nomogram to Predict Good Neoangiogenesis After Indirect Revascularization Surgery in Patients with Moyamoya Disease: a Case-control Study

Indirect bypass surgery is an effective treatment for moyamoya disease (MMD), but the success of the surgery depends on the formation of spontaneous collateral vessels, which cannot be accurately predicted before surgery. Developing a prediction nomogram model for neoangiogenesis in patients after indirect revascularization surgery can aid surgeons in identifying suitable candidates for indirect revascularization surgery. This retrospective observational study enrolled patients with MMD who underwent indirect bypass surgery from a multicenter cohort between December 2010 and December 2018. Data including potential clinical and radiological predictors were obtained from hospital records. A nomogram was generated based on a multivariate logistic regression analysis identifying potential predictors of good neoangiogenesis. A total of 263 hemispheres of 241 patients (mean ± SD age 24.38 ± 15.78 years, range 1-61 years) were reviewed, including 168 (63.9%) hemispheres with good postoperative collateral formation and 95 (36.1%) with poor postoperative collateral formation. Based on multivariate analysis, a nomogram was formulated incorporating four predictors, including age at operation, abundance of ICA moyamoya vessels, onset type, and Suzuki stage. The C-index for this nomogram was 0.80. Calibration curve and decision-making analysis validated the fitness and clinical application value of this nomogram. The nomogram developed in this study exhibits high accuracy in predicting good neoangiogenesis after indirect revascularization surgery in MMD patients. This model can be very helpful for clinicians when making decisions about surgical strategies for MMD patients in clinical practice.

Superficial Temporal Artery Size Changes After Encephaloduroarteriosynangiosis for the Treatment of Moyamoya Disease

BACKGROUND AND OBJECTIVE

Surgery is the mainstay of stroke prevention in patients with symptomatic moyamoya disease (MMD). We present the results of a single-center retrospective study of indirect revascularization surgery for adult MMD, emphasizing angiographic outcomes, including dilation of the superficial temporal artery and formation of new collaterals.

METHODS

A prospectively maintained database of procedures performed for MMD was reviewed. Adult patients treated with indirect revascularization and with long-term angiographic follow-up were included. Preoperative and postoperative angiographic images and baseline and procedural characteristics were analyzed. A Wilcoxon signed-rank test was used to test the hypothesis that the superficial temporal artery increases in diameter postoperatively.

RESULTS

We identified 40 hemispheres in 27 patients, of which 35 had a sufficient angiographic follow-up. Bilateral procedures were performed on 16 patients. Most patients were female (72.5%), with a median age of 43 years old. The most common clinical presentation was ischemic stroke in 59.3% of cases. All patients underwent an encephaloduroarteriosynangiosis for treatment. A follow-up angiogram was performed at a median of 13.8 months postoperatively, showing superficial temporal artery (STA)-derived collaterals in 71.4% and collateral ingrowth via the burr holes in 61.8% of cases. Disease progression was evident in 34.3% of hemispheres. The normalized STA diameter was significantly increased postoperatively (2.4 to 3 mm; P < 0.05). A univariate analysis revealed that transdural collaterals and hyperlipidemia may affect collateral ingrowth from the STA, and no other patient- or procedure-related factors, including replacement of the bone flap, impacted on this.

CONCLUSIONS

A significant increase in STA diameter on follow-up angiography after encephaloduroarteriosynangiosis was found; however, this was not directly associated with STA collateral development. Rates of postoperative transient ischemic attacks were low, and no patients had a new ischemic or hemorrhagic stroke at last follow-up. The presence of transdural collaterals and the absence of hyperlipidemia were associated with STA collateral development on follow-up angiography, but the causality of this finding is unclear.

Association between angiographic and clinical outcomes after STA-MCA bypass in adult moyamoya disease

BACKGROUND AND PURPOSE

As an angiographic outcome, postoperative collateral formation (PCF) is commonly used to evaluate the effect of STA-MCA bypass in moyamoya disease (MMD), but whether it can reliably reflect clinical outcomes is still unclear. We investigated the association between PCF and clinical outcomes in adult MMD.

METHODS

All STA-MCA bypass procedures performed from January 2013 to December 2019 were screened in this prospective cohort study. Patients who acquired presurgical and follow-up catheter angiography were included. The clinical outcomes consisted of symptom improvement and recurrent cerebrovascular events. Logistic and Cox regression and Kaplan-Meier analyses were performed to explore the association between PCF and clinical outcomes.

RESULTS

Of 165 included symptomatic hemispheres of 154 patients, 104 (63.0%) and 61 (37.0%) had good and poor PCF, respectively. The hemispheres with good PCF were younger (p = 0.004) and had a higher incidence of hemodynamic dysfunction on admission (p < 0.001) than those with poor PCF. Multivariate logistic regression analysis showed that the good PCF (odd ratio, 28.96; 95% confidence interval (CI), 9.12-91.98; p < 0.001) was associated with a higher incidence of symptom improvement. Multivariate Cox regression analysis showed that the poor PCF (hazard ratio, 3.77; 95% CI, 1.31-10.84; p = 0.014) was associated with a higher incidence of recurrent cerebrovascular events. In the hemorrhagic-onset hemispheres, good PCF group had a higher incidence of symptom improvement (p < 0.001) and a longer hemorrhage-free time (p = 0.031). In the ischemic-onset hemispheres, good PCF group also had a higher incidence of symptom improvement (p < 0.001) and a longer ischemia-free time (p = 0.028).

CONCLUSIONS

As a angiographic outcome, collateral formation is a qualified surrogate measure for clinical outcomes after STA-MCA bypass in adult MMD.

Encephaloduroarteriosynangiosis for Symptomatic Intracranial Atherosclerotic Arterial Steno-Occlusive Disease: Clinical and Radiological Outcomes

BACKGROUND

This study investigated the long-term clinical and angiographic outcomes of encephaloduroarteriosynangiosis treatment for symptomatic intracranial atherosclerotic arterial steno-occlusive disease to further evaluate the potential therapeutic role of encephaloduroarteriosynangiosis in this population.

METHODS AND RESULTS

A total of 152 adult patients with symptomatic intracranial atherosclerotic arterial steno-occlusive disease who were treated with encephaloduroarteriosynangiosis and intensive medical management across 3 tertiary centers in China between January 2011 and September 2019 were retrospectively included. The primary outcomes were defined as postoperative cerebrovascular events, including ischemic and hemorrhagic stroke. The postoperative neovascularization was analyzed qualitatively and quantitatively by using angiography. Clinical, radiological, and long-term follow-up data were analyzed using Cox regression, logistic regression, and linear regression analyses. Primary outcome rates were 3.2% (5/152) within 30 days, 6.6% (10/152) within 2 years, 9.2% (14/152) within 5 years, and 11.1% (17/152) during a median 9.13 years follow-up. Initial infarction symptoms were positively associated with recurrent ischemic stroke. Additionally, posterior circulation involvement and coexisting cardiac disease indicated poorer neurological status, whereas encephaloduroarteriosynangiosis neovascularization efficacy was negatively associated with older age and vascular risk factors but positively associated with posterior circulation involvement.

CONCLUSIONS

Encephaloduroarteriosynangiosis plus intensive medical management appears efficacious and safe for symptomatic intracranial atherosclerotic arterial steno-occlusive disease, with low perioperative risk and favorable long-term results. Further prospective trials are needed to verify its efficacy and determine the optimal patient selection criteria.

Risk Factors for Preoperative Cerebral Infarction in Infants with Moyamoya Disease

There have been few reports on the risk factors for preoperative cerebral infarction in childhood moyamoya disease (MMD) in infants under 4 years. The aim of this retrospective study is to identify clinical and radiological risk factors for preoperative cerebral infarction in infants under 4 years old with MMD, and the optimal timing for EDAS was also considered. We retrospectively analyzed the risk factors for preoperative cerebral infarction, confirmed by magnetic resonance angiography (MRA), in pediatric patients aged ˂4 years who underwent encephaloduroarteriosynangiosis between April 2005 and July 2022. The clinical and radiological outcomes were determined by two independent reviewers. In addition, potential risk factors for preoperative cerebral infarction, including infarctions at diagnosis and while awaiting surgery, were analyzed using a univariate model and multivariate logistic regression to identify independent predictors of preoperative cerebral infarction. A total of 160 hemispheres from 83 patients aged <4 years with MMD were included in this study. The mean age of all surgical hemispheres at diagnosis was 2.17±0.831 years (range 0.380-3.81 years). In the multivariate logistic regression model, we included all variables with P<0.1 in the univariate analysis. The multivariate logistic regression analysis indicated that preoperative MRA grade (odds ratio [OR], 2.05 [95% confidence interval [CI], 1.3-3.25], P=0. 002), and age at diagnosis (OR, 0.61 [95% CI, 0.4-0.92], P=0. 018) were predictive factors of infarction at diagnosis. The analysis further indicated that the onset of infarction (OR, 0.01 [95% CI, 0-0.08], P<0.001), preoperative MRA grade (OR, 1.7 [95% CI, 1.03-2.8], P=0.037), and duration from diagnosis to surgery (Diag-Op) (OR, 1.25 [95% CI, 1.11-1.41], P<0.001) were predictive factors for infarction while awaiting surgery. Moreover, the regression analysis indicated that family history (OR, 8.88 [95% CI, 0.91-86.83], P=0.06), preoperative MRA grade (OR, 8.72 [95% CI, 3.44-22.07], P<0.001), age at diagnosis (OR, 0.36 [95% CI, 0.14-0.91], P=0.031), and Diag-Op (OR, 1.38 [95% CI, 1.14-1.67], P=0.001) were predictive factors for total infarction. Therefore, during the entire treatment process, careful observation, adequate risk factor management, and optimal operation time are required to prevent preoperative cerebral infarction, particularly in pediatric patients with a family history, higher preoperative MRA grade, duration from diagnosis to operation longer than 3.53 months, and aged ˂3 years at diagnosis.

The effects of anastomoses between anterior and posterior circulation on postoperative prognosis of patients with moyamoya disease

BACKGROUND

Moyamoya disease (MMD) is a chronic ischemic cerebrovascular disease. Collateral circulation in MMD has emerged as a research focus. Our aims were to assess the impact of anastomoses between the anterior and posterior circulations on the prognosis of MMD patients.

METHODS

We reviewed the preoperative digital subtraction angiography images of patients with MMD who underwent revascularization surgery at our hospital between March 2014 and May 2020 and divided the patients into two groups: those with anastomoses (PtoA group) and those without anastomoses (non-PtoA group). The differences in follow-up (more than 6 months) collateral vessel establishment (Matsushima grade) and the modified Rankin Scale (mRS) were compared between the two groups as well as between the patients with different degrees of anastomoses. The early complications following revascularization were also compared between the two groups.

RESULTS

This study included 104 patients with MMD, of which 38 were non-PtoA and 66 were PtoA. There were no significant differences in Matsushima score (P = 0.252) and mRS score (P = 0.066) between the two groups. In addition, Matsushima score (P = 0.243) and mRS score (P = 0.360) did not differ significantly between patients with different degrees of anastomoses. However, the non-PtoA group had a significantly higher rate of cerebral hyperperfusion syndrome (CHS) than the PtoA group (34.2% vs 16.7%, P = 0.041).

CONCLUSION

MMD patients without anastomoses between anterior and posterior circulations preoperatively should be vigilant of the occurrence of CHS in the early stages after revascularization.

Moyamoya syndrome in a patient with D-2-hydroxyglutaric aciduria type II: a rare association

PURPOSE

Several underlying conditions of moyamoya syndrome (MMS) are well established, but so far, D-2-hydroxyglutaric aciduria (D-2-HGA) has not been mentioned. We are the first to describe a case of a patient suffering from D-2-HGA developing MMS.

METHODS

The co-occurrence of D-2-HGA and MMS in a patient is reported. Furthermore, we describe the neurosurgical revascularization procedure performed and report on the follow-up.

RESULTS

A 7-year-old girl suffering from D-2-HGA developed two transient ischemic attacks (TIAs). Using MRI/MRA and invasive angiography MMS was diagnosed. We performed an encephalo-duro-arterio-myo-synangiosis (EDAMS) as an indirect revascularization procedure first on the right and 2 months later on the left hemisphere. We have followed her up until the age of 10. Since the second surgery, she has not suffered further TIAs and is in a better general medical condition.

CONCLUSION

Even though children with D-2-HGA often suffer epileptic attacks, every new (transient) neurological deficit should be followed up by an MRI/MRA so as not to oversee a possible underlying MMS. After diagnosis, EDAMS in combination with acetylsalicylic acid (ASA) is recommended to prevent further ischemic events.

Stroke and Disease Progression During Long-Term Follow-Up of Patients with Moyamoya Disease Older Than 50 Years

OBJECTIVE

The long-term prognosis of elderly patients with moyamoya disease (MMD) is not fully understood and needs to be elucidated.

METHODS

MMD patients who first visited our institute between 1999 and 2019, were ≥ 50 years of age, and were followed for ≥1 year were retrospectively included. Follow-up data such as stroke and disease progression on magnetic resonance angiography (MRA) were collected from medical records. The surgical outcomes of ischemic patients treated with indirect revascularization were assessed.

RESULTS

Of the 60 patients included (mean (standard deviation) = 57.0 (5.5) years, 38 females), 9 patients initially received indirect revascularization, 3 patients received direct revascularization, and 49 patients were treated conservatively. During the 57.4 (53.7) month follow-up, the symptomatic stroke rate (person-year %) was 2.79%, and MRA progression was 3.14%. Symptomatic patients had a greater rate of symptomatic stroke than asymptomatic patients did (1.46%-5.74% vs. 0.94%, P = 0.15), while MRA progression was more common in asymptomatic patients (0%-3.83% vs. 5.64%, P = 0.22). Among the 14 hemispheres of 11 patients who underwent indirect revascularization, 13/14 (92.9%) demonstrated good neovascularization and no ischemic stroke occurred after surgery.

CONCLUSIONS

In elderly patients with MMD, MRA progression was not uncommon, especially in asymptomatic patients. Symptomatic patients exhibited a high symptomatic stroke rate, and indirect revascularization seems to be effective at reducing future ischemic stroke in ischemic patients with misery perfusion. Because follow-up events were not uncommon, lifelong follow-up seems necessary for elderly MMD patients, as well as for younger patients.

Longitudinal evaluation of cerebral perfusion evolution after revascularization surgery in moyamoya disease by CT perfusion

OBJECTIVE

To assess the longitudinal evolution of cerebral perfusion after revascularization surgery in patients with moyamoya disease (MMD) by CT perfusion (CTP).

MATERIALS AND METHODS

Thirty-one clinically confirmed MMD patients (12 males and 19 females, average age: 33.26 y, Suzuki stages 3 and 4: 19 and 11, respectively) who underwent revascularization surgery (bilateral (n=13) or unilateral (n=18)) were studied retrospectively. All patients underwent CTP examinations before and in the week after surgery and long-term (>3 months). CTP metrics (CBF, CBV, MTT, TTP, and delay TTP) were derived. The corresponding CTP metric values of the ROIs, which were manually drawn in the white matter (WM) and gray matter (GM), were recorded.

RESULTS

Six patients developed a new or progressive cerebral infarction/hemorrhage. In all patients, compared with the preoperative level, the TTP of GM and WM decreased in the short term after the surgery (P ≤ 0.005). Concurrently, the WM CBF increased significantly a week after surgery (P =0.02). However, in the long-term follow-up, the CBV and CBF in the GM and WM decreased to equal to or lower than the preoperative level, especially for CBV in the WM (P =0.012). Furthermore, cerebral perfusion began to decrease in the sixth month, and a continuous decline was observed over the next two months. It returned to the presurgical level after one year. In addition, the improvement in postsurgical perfusion was greater in Suzuki stage 3 patients than stage 4 patients.

CONCLUSION

Cerebral perfusion in patients with MMD improved shortly after surgery. However, in the long-term, brain perfusion decreased, most seriously in 6-8 months postoperatively, which might indicate that patients with MMD need timely follow-up and long-term intervention.

Comprehensive Profiling of Secreted Factors in the Cerebrospinal Fluid of Moyamoya Disease Patients

Moyamoya disease (MMD) is characterized by progressive occlusion of the intracranial internal carotid arteries, leading to ischemic and hemorrhagic events. Significant clinical differences exist between ischemic and hemorrhagic MMD. To understand the molecular profiles in the cerebrospinal fluid (CSF) of MMD patients, we investigated 62 secreted factors in both MMD subtypes (ischemic and hemorrhagic) and examined their relationship with preoperative perfusion status, the extent of postoperative angiographic revascularization, and functional outcomes. Intraoperative CSF was collected from 32 control and 71 MMD patients (37 ischemic and 34 hemorrhagic). Multiplex Luminex assay analysis showed that 41 molecules were significantly elevated in both MMD subtypes when compared to controls, including platelet-derived growth factor-BB (PDGF-BB), plasminogen activator inhibitor 1 (PAI-1), and intercellular adhesion molecule 1 (ICAM1) (p < 0.001). Many of these secreted proteins have not been previously reported in MMD, including interleukins (IL-2, IL-4, IL-5, IL-7, IL-8, IL-9, IL-17, IL-18, IL-22, and IL-23) and C-X-C motif chemokines (CXCL1 and CXCL9). Pathway analysis indicated that both MMD subtypes exhibited similar cellular/molecular functions and pathways, including cellular activation, migration, and inflammatory response. While neuroinflammation and dendritic cell pathways were activated in MMD patients, lipid signaling pathways involving nuclear receptors, peroxisome proliferator-activated receptor (PPAR), and liver X receptors (LXR)/retinoid X receptors (RXR) signaling were inhibited. IL-13 and IL-2 were negatively correlated with preoperative cerebral perfusion status, while 7 factors were positively correlated with the extent of postoperative revascularization. These elevated cytokines, chemokines, and growth factors in CSF may contribute to the pathogenesis of MMD and represent potential future therapeutic targets.

High Level of Serum Complement C3 Expression is Associated with Postoperative Vasculopathy Progression in Moyamoya Disease

Background

The immune system plays an important role in the onset and development of moyamoya disease (MMD), but the specific mechanisms remain unclear. This study aimed to explore the relationship between the expression of complements and immunoglobulin in serum and progression of MMD.

Methods

A total of 84 patients with MMD and 70 healthy individuals were enrolled. Serum immunoglobulin and complement C3 and C4 expression were compared between healthy individuals and MMD patients. Follow-up was performed at least 6 months post-operation. Univariate and multivariate analysis after adjusting different covariates were performed to explore predictive factors associated with vasculopathy progression. A nomogram basing on the results of multivariate analysis was established to predict vasculopathy progression.

Results

Compared to healthy individuals, MMD patients had significantly lower expression of serum complements C3 (P = 0.003*). Among MMD patients, C3 was significantly lower in those with late-stage disease (P = 0.001*). Of 84 patients, 27/84 (32.1%) patients presented with vasculopathy progression within a median follow-up time of 13.0 months. Age (P=0.006*), diastolic blood pressure (P=0.004*) and serum complement C3 expression (P=0.015*) were associated with vasculopathy progression after adjusting different covariables.

Conclusion

Complement C3 is downregulated in moyamoya disease and decreases even further in late-Suzuki stage disease. Age, diastolic blood pressure and serum complement C3 expression are associated with vasculopathy progression, suggesting that the complement might be involved in the development of moyamoya disease.

Clinical and genetic factors associated with contralateral progression in unilateral moyamoya disease: Longitudinal and Cross-Sectional Study

Objective

This study aimed to explore the long-term outcome of unilateral moyamoya disease and predict the clinical and genetic factors associated with contralateral progression in unilateral moyamoya disease.

Methods

We retrospectively recruited unilateral moyamoya disease patients with available genetic data who underwent encephaloduroarteriosynangiosis (EDAS) surgery at our institution from January 2009 to November 2017. Long-term follow-up data, including clinical outcomes, angiographic features, and genetic information, were analyzed.

Results

A total of 83 unilateral moyamoya disease patients with available genetic data were enrolled in our study. The mean duration of clinical follow-up was 7.9 ± 2.0 years. Among all patients, 19 patients demonstrated contralateral progression to bilateral disease. Heterozygous Ring Finger Protein 213 p.R4810K mutations occurred significantly more frequently in unilateral moyamoya disease patients with contralateral progression. Furthermore, patients with contralateral progression typically demonstrated an earlier age of onset than those with non-progressing unilateral moyamoya disease. In the contralateral progression group, posterior circulation involvement was observed in 11 (11/19, 57.9%) patients compared to 12 (12/64, 18.8%) in the non-contralateral progression group (P = 0.001). The time to peak of cerebral perfusion and neurological status showed significant postoperative improvement.

Conclusion

Long-term follow-up revealed that the EDAS procedure might provide benefits for unilateral moyamoya disease patients. Ring Finger Protein 213 p.R4810K mutations, younger age, and posterior circulation involvement might predict the contralateral progression of unilateral moyamoya disease.

Usefulness of STA ultrasonography parameters after STA-MCA bypass in patients with moyamoya disease: A short review

STA bypass assessment by ultrasonography after bypass surgery in patients with moyamoya disease is minimally invasive and can be performed repeatedly. With STA bypass assessment by ultrasonography, it was shown that in the short term, blood flow that passes through the STA peaks approximately 5 days after the bypass surgery and then gradually decreases over 7 days. In the medium and long terms, it has been shown that the blood flow through the bypass decreases, compared with that during the first postoperative week, and continues for approximately half a year. The ultrasonographic STA parameters can also clearly indicate bypass patency, but there remains some discussion regarding bypass function. Although some reports have tried to show that these parameters are also useful for predicting acute-phase TNEs and predicting the future of bypass function, no studies have yet examined these parameters in detail in relation to the state of cerebral circulation or degree of residual antegrade flow, and additional studies are needed in the future.

A Vessel Wall MRI Investigation in Patients With Moyamoya or Quasi-Moyamoya Disease: Diagnosis, Features, and Outcomes

BACKGROUND AND PURPOSE

None of the previous studies have investigated the pathologic authenticity of affected arteries in moyamoya disease (MMD) and Quasi-MMD diagnosed by angiography. This study aimed to confirm the angiographic diagnosis of moyamoya as well as investigate the pathologic mechanisms in angiographically proven MMD and Quasi-MMD using high-resolution magnetic resonance imaging (MRI) in a large sample.

METHODS

We prospectively studied 116 patients who had angiographically proven MMD and Quasi-MMD. Each affected internal carotid artery, and middle cerebral artery was independently evaluated. In addition, clinical features and postoperative outcomes were compared between hemispheres with MMD and moyamoya syndrome (MMS).

RESULTS

Among 116 patients analyzed, 88 and 22 patients had angiographically proven MMD and Quasi-MMD, respectively. high-resolution magnetic resonance imaging confirmed bilateral MMD in 73 (83.0%) patients, 1 hemisphere with MMD and the other with intracranial atherosclerotic disease (ICAD) in 10 (11.4%) patients, and bilateral hemispheres with different vasculopathies in 5 (5.7%) patients. Detailed analysis of 204 affected hemispheres showed that several combinations of different vasculopathies were observed in the internal carotid artery and middle cerebral artery of the same hemisphere, such as ICAD-ICAD, ICAD-MMD, dissection-ICAD, and dissection-MMD. Hemispheres were assigned to MMD and MMS groups according to their vasculopathies. Transient ischemic attack occurred more frequently in hemispheres with MMD (48.1% versus 21.1%, P =0.024), whereas symptomatic ischemia was more common in hemispheres with MMS (57.9% versus 24.9%, P =0.002). However, postoperative cerebral infarction, symptom improvement and neo-formative collaterals showed no significant difference between hemispheres with MMD and MMS ( P >0.05).

CONCLUSIONS

Patients with angiographically proven MMD or Quasi-MMD needed more accurate evaluation combined with high-resolution magnetic resonance imaging. Highly selected patients with MMS might also obtain benefits from surgical revascularization.

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.

[Moyamoya disease in adults: treatment methods in modern era]

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

Ivy Sign: Usefulness in Diagnosis and Prognosis Prediction of Moyamoya Disease

BACKGROUND

Moyamoya disease (MMD) cannot be found commonly as a rare type compared with other vascular disease, such as aneurysm. However, it cannot be ignored for its high fatality and disability rates. In addition, exact pathogenesis study of this disease is still on the way. The ivy sign is always observed in MMD, but the clinical importance of this sign in MMD isn't clearly known. The main purpose of this research was to specifically investigate the clinical significance.

METHODS

In this retrospective cohort study to gather the baseline clinical and imaging study, the patients with MMD were hospitalized from January 2016 to 2020. In the analysis, univariate and multivariate logistic regression was used to testify whether ivy sign was independently associated with MMD characteristics including cerebrovascular morphology, cerebral hemodynamics, cerebrovascular events, and postoperative collateral formation (PCF).

RESULTS

We included 156 patients with 312 hemispheres. As for the result of multivariate logistic regression analysis, we could discover a fact that ivy sign was tightly connected to the Suzuki stage ≥IV (odds ratio [OR], 1.386; 95% confidence interval [CI], 1.055-1.822; P = 0.019), cerebral blood flow (CBF) decreased type (OR, 2.330; 95% CI, 1.733-3.133; P = 0.000), age acted as a protective factor for CBF (OR, 0.966; 95% CI, 0.946-0.986; P = 0.001), the elder was more likely associated with decreased CBF. Ivy sign also played a significant role in ischemic cerebrovascular events (OR, 5.653; 95% CI, 3.092-10.336; P = 0.003), their remarkable connection could be seen on the study. We could also find that ivy sign was closely connected to the good PCF (OR, 2.830; 95% CI, 1.329-6.027; P = 0.007), and we couldn't ignore the fact that age was associated with good PCF as well (OR, 0.933; 95% CI, 0.882-0.987; P = 0.015).

DISCUSSION

We could be more aware of the connection between ivy sign and Moyamoya disease from this study in order to implement diagnosis, treatment, and prognosis more efficiently.

Analysis of Factors Affecting Good Neovascularization After Indirect Bypass Surgery: A Two-center Retrospective Study

OBJECTIVE

The purpose of this study was to analyze factors affecting good neovascularization after indirect bypass surgery.

METHODS

From August 2000 to July 2020, postoperative image results and medical records of 132 patients (159 hemispheres) who underwent EDAS of indirect bypass surgery at two institutions were reviewed retrospectively. Based on DSA results, angiogenesis after indirect bypass was divided into "good" or "poor" according to the Matsushima criteria. STA flap length affecting GPN were analyzed in the entire group (n = 159) and a MMD group (n = 134).

RESULTS

In the entire group, GPN after EDAS was observed in 94 (59.1%) hemispheres. Age, MMD, hypertension, and bone flap size were identified as significant factors in univariate analysis. Also, in the MMD group, 86 (64.2%) hemispheres showed GPN. Hypertension and bone flap size were significant factors in both univariate and multivariate analyses. Cutoff values of bone flap size and GPN were 47.91 cm2 in the entire group and the MMD group.

CONCLUSIONS

In all patients who received EDAS, good postoperative neovascularization was significant in those with a young age, MMD, without hypertension, and large bone flap size. No hypertension and large bone flap size were meaningful factors in the MMD group. AUROC showed that an appropriate bone flap size was 47.91 cm2. However, a further controlled prospective study is needed.

Evaluation of surgical revascularization procedure outcomes for adult Moyamoya disease: a computed tomography perfusion-based study

BACKGROUND

The effectiveness of surgical interventions, whether direct or indirect, for Moyamoya disease (MMD) remains controversial. This study aims to investigate CT perfusion (CTP) as an objective method to evaluate the outcomes of different surgical modalities for adult MMD.

METHODS

The clinical and imaging data of 41 patients who underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass and 43 who received encephaloduroarteriosynangiosis (EDAS) were retrospectively analyzed. Intra- and intergroup differences in the Modified Rankin Scale (mRS) score, the change in clinical symptoms, collateral grade, and CTP parameters pre- and postoperatively were compared.

RESULTS

The overall level of the change in clinical symptoms in the STA-MCA group was higher than in the EDAS group (p < 0.05). In the operative area, the relative cerebral blood flow (rCBF) was significantly higher whereas the relative time to peak (rTTP) and the relative mean transit time (rMTT) were significantly lower in the STA-MCA and EDAS groups postoperatively than preoperatively (all p < 0.05). In the ipsilateral frontal lobe and basal ganglia, the postoperative rCBF was significantly higher, and the rTTP was significantly lower than the preoperative in the STA-MCA group (all p < 0.05). The postoperative rCBF improvement was higher in each brain area for STA-MCA than in the EDAS group (all p < 0.05).

CONCLUSION

Highlighting the utility of CTP, this study demonstrates its effectiveness in assessing postoperative cerebral hemodynamic changes in adult MMD patients. STA-MCA yielded a larger postoperative perfusion area and greater improvement compared to EDAS, suggesting CTP's potential to elucidate symptom variation between two surgical revascularization procedures.

CRITICAL RELEVANCE STATEMENT

We analyzed computed tomography perfusion parameters in pre- and postoperative adult Moyamoya disease patients undergoing superficial temporal artery-middle cerebral artery bypass and encephaloduroarteriosynangiosis. Our findings suggest computed tomography perfusion's potential in objectively elucidating symptom variations between these surgical revascularization approaches for MMD.

KEY POINTS

• Postoperative perfusion improvement is only confined to the operative area after EDAS. • Besides the operative area, postoperative perfusion in the ipsilateral frontal lobe and basal ganglia was also improved after STA-MCA. • The degree of perfusion improvement in each brain area in the STA-MCA group was generally greater than that in the EDAS group.

Comparison Between the Efficacy of a Flow Diverter and Interventional Trapping with Bypass in the Treatment of Unruptured Large- or Giant-Sized ICA Aneurysms

OBJECTIVE

Management of large- or giant-sized internal carotid artery aneurysms (LICAAs) remains challenging. Whether a flow diverter device (FDD) or interventional trapping with extracranial-intracranial bypass (ITB) is better, remains unclear.

METHODS

We conducted a multicenter retrospective analysis of unruptured LICAA patients treated with FDD or ITB at 3 medical centers. Both the effectiveness and safety results of FDD and ITB were compared.

RESULTS

In total, 101 aneurysms in 95 patients treated with FDDs and 36 aneurysms in 36 patients managed with ITBs were included (September 2014-June 2021). There was no significant difference between the groups in the complete obliteration rate 1 year after surgery (P = 0.101). There were 2 relapse cases (2.0%) and 4 retreated cases (4.0%) in the FDD group and 1 relapse case (2.8%) and 2 retreated cases (5.6%) in the ITB group. Neither the relapse rates nor retreat rates between groups were significantly different. The neurological morbidity rates were 4.0% (4/101) and 2.8% (1/36) in the FDD group and ITB group, respectively, and were not significantly different. There was 1 mortality case in each group, and the mortality rates were not significantly different (P = 0.443). Both the perioperative and overall (perioperative plus long-term) complication rates in the FDD group were significantly lower than those in the ITB group (P = 0.033, P = 0.039).

CONCLUSIONS

FDD had comparable surgical efficacy and a significantly lower postoperative complication rate to traditional ITB. FDD might be preferable to ITB as a treatment modality for LICAA.

Comparison of Bifrontal Craniotomy and Multiple Burr Hole Encephalogaleoperiosteal-Synangiosis for Pediatric Moyamoya Disease: An Experience of 346 Patients

BACKGROUND AND OBJECTIVES

Moyamoya disease (MMD) is a steno-occlusive disease treated with revascularization surgery. Craniotomy and multiple burr hole encephalogaleoperiosteal-synangiosis (EGPS) are used for revascularization of the anterior cerebral artery territory. The aim of this study was to compare the clinical outcome between the 2 surgical methods in pediatric patients with MMD.

METHODS

A retrospective review of patients with MMD who underwent bifrontal indirect bypass surgery was performed. Clinical features, perioperative data, and angiographic, perfusion, and functional outcomes were compared between the 2 groups. Propensity score matching was performed to compare the perioperative characteristics and clinical outcomes.

RESULTS

A total of 346 patients were included in this study, 111 patients underwent bifrontal craniotomy EGPS, and 235 patients had bifrontal multiple burr hole EGPS. An insignificant higher rate of postoperative infarction (11.7% vs 5.5%, P = .072) and more postoperative hemorrhage occurred in the craniotomy EGPS group (3.6% vs 0%, P = .004). Of the 83 patients selected with propensity score matching for each group, the duration of operation was shorter ( P < .001) and the amount of intraoperative bleeding was significantly less in the multiple burr hole EGPS group ( P = .008). There was no difference in clinical outcomes between the 2 groups.

CONCLUSION

Bifrontal multiple burr hole EGPS has benefits over craniotomy with shorter surgical time, less intraoperative bleeding, fewer postoperative complications, and comparable perfusion and functional outcomes. Multiple burr hole EGPS is a safe and effective method that might be considered for revascularization of the anterior cerebral artery territory in pediatric patients with MMD.

Superior Visualization of Neovascularization with Silent Magnetic Resonance Angiography Compared to Time-of-Flight Magnetic Resonance Angiography After Bypass Surgery in Moyamoya Disease

OBJECTIVE

The evaluation of postsurgical neoangiogenesis in patients with moyamoya disease (MMD) is crucial for appropriate patient management. This study aimed to assess the visualization of neovascularization after bypass surgery using noncontrast-enhanced silent magnetic resonance angiography (MRA) with ultrashort echo time and arterial spin labeling.

METHODS

After bypass surgery, 13 patients with MMD were followed up for >6 months between September 2019 and November 2022. They underwent silent MRA in the same session as time-of-flight magnetic resonance angiography (TOF-MRA) and digital subtraction angiography (DSA). Two observers independently rated the visualization of neovascularization in both types of MRA from 1 (not visible) to 4 (nearly equal to DSA), with reference to DSA images as the standard.

RESULTS

The mean scores were significantly higher for silent MRA compared with TOF-MRA (3.81 ± 0.48 and 1.92 ± 0.70, respectively) (P < 0.01). The intermodality agreements were 0.83 and 0.71 for silent MRA and TOF-MRA, respectively. TOF-MRA depicted the donor artery and recipient cortical artery after direct bypass surgery, although fine neovascularization developed after indirect bypass surgery was poorly visualized. Silent MRA could reveal the developed bypass flow signal and perfused middle cerebral artery territory, which was almost equal to the DSA images.

CONCLUSIONS

Silent MRA achieves better visualization of postsurgical revascularization in patients with MMD than TOF-MRA. Moreover, it may have the potential to provide visualization of the developed bypass flow equivalent to DSA.

Safety and efficacy of aspirin after combined cerebral revascularization for ischemic moyamoya disease: A prospective study

Objective

To analyze the safety and efficacy of regular aspirin use after combined cerebral revascularization in patients with ischemic moyamoya disease.

Methods

From December 2020 to October 2021, a total of 326 patients diagnosed with ischemic moyamoya disease by global cerebral angiography and undergoing first-time combined cerebral revascularization at the Moyamoya Disease Diagnosis and Treatment Research Center of our hospital were selected. Combined cerebral revascularization: superficial temporal artery-middle cerebral artery (STA-MCA) +encephalo-duro-myo-synangiosis (EDMS).Patients were screened by 2 senior physicians according to established inclusion/exclusion criteria. Patients were divided into aspirin and non-aspirin groups based on whether they received regular oral aspirin after surgery. A total of 133 patients were enrolled in the aspirin group. A total of 71 patients (204 cases) were enrolled in the non-aspirin group. Related data were collected before and 1 year after surgery and statistically analyzed to assess the prognosis of both groups.

Results

In the two groups, the mRS Score was significantly different after one year (P = 0.023). TIA occurred in 26 patients (19.5%) in the aspirin group and 27 patients (38.0%) in the non-aspirin group within one year after surgery, and the difference between the two groups was statistically significant (P = 0.004). There was no significant difference in cerebral perfusion stage, the improvement rate of cerebral perfusion, Matsushima grading, bypass patency, and other complications within one year after the operation (P > 0.05).

Conclusions

In patients with ischemic moyamoya disease who underwent combined cerebral revascularization, postoperative administration of aspirin can reduce the incidence of TIA without increasing the risk of bleeding, but it can not significantly improve the cerebral perfusion of the operation side, Matsushima grading, and bypass patency.

Follow-up outcomes of different bypass surgical modalities for adults with ischaemic-type moyamoya disease

PURPOSE

The preferred surgical method for treating adults with moyamoya disease (MMD) remains controversial. The purpose of this study was to compare the efficacy of different surgical methods in the treatment of adults with ischaemic-type MMD.

METHODS

We retrospectively analyzed the data of patients with ischaemic-type MMD who underwent indirect bypass (IB), direct bypass (DB), or combined bypass (CB) at the First Affiliated Hospital of Zhengzhou University from January 2013 to December 2019. Postoperative complications, improvements in neurological function, haemodynamics, recurrent stroke and neovascularization were compared.

RESULTS

A total of 310 adults (371 hemispheres) with ischaemic-type MMD were included in our study. Ninety, 127, and 154 hemispheres underwent IB, DB and CB, respectively. A total of 24 (6.5%) ischaemic events and 8 (2.8%) symptomatic hyperperfusion events occurred after the operations. There was no significant difference in postoperative complications among the three types of surgery (p = 0.300). During the follow-up period, there were 21 cases (5.7%) of recurrent ischaemia and 12 cases (3.2%) of recurrent haemorrhage. Kaplan-Meier survival analysis showed that the ischaemia-free survival of the CB group was significantly longer than that of the IB group (p = 0.047), but there was no significant difference in haemorrhage-free survival among the three groups (p = 0.660). Six months after the operation, DB and CB were superior to IB in improving cerebral blood flow and neovascularization (p = 0.002), but there was no significant difference in the improvement of neurological function among the three groups at the last follow-up (p = 0.784).

CONCLUSION

The three surgical methods achieved satisfactory results in the treatment of ischaemic-type MMD. DB and CB can significantly improve haemodynamics and reduce recurrent stroke. In terms of improving neurological function, the curative effect of the three surgical methods remains to be further explored.

Wide Arterial Sparing Encephalo-Duro-Synangiosis for Moyamoya: Surgical Technique and Outcomes

BACKGROUND

Moyamoya is managed by surgical revascularization, but no standardized method has yet been universally adopted.

OBJECTIVE

To describe a new indirect bypass technique for pediatric moyamoya, wide arterial sparing encephalo-duro-synangiosis (WASEDS), which provides a much wider area of revascularization with minimal compromise to the middle meningeal arterial tree compared with traditional procedures. Initially used as a salvage technique after failed encephalo-duro-arterio-synangiosis, its success later motivated its use as a first-line procedure.

METHODS

Clinical and radiographic records of patients who underwent WASEDS for moyamoya from 2009 to 2020 were reviewed. Brain perfusion relative cerebral blood volume on the side of the WASEDS procedure was calculated. Two-tailed paired t tests were performed to identify the statistically significant differences ( P ≤ .05).

RESULTS

WASEDS was successfully performed on 8 patients for a total of 14 cerebral hemispheres. Age ranged from 2 to 25 years. There were no mortalities. The average clinical and radiographic follow-up was 49.79 months (range 2-126 months), demonstrating improvement in neurological condition and no postoperative stroke and significant diminution or cessation of transient ischemic attacks in all patients. Relative cerebral blood volume increased 9.24% after the WASEDS procedure ( P = .012). There were no neurological complications. There were 2 pseudomeningoceles related to the extensive dural openings.

CONCLUSION

WASEDS is a safe and effective indirect revascularization technique for both primary and salvage techniques. It provides an extensive area of cortical revascularization with no compromise of the middle meningeal vasculature and subjective reports of early improvement in cognition and behavior. The main disadvantage is elevated risk of pseudomeningocele secondary to the large craniotomy.

Postoperative vascular event prediction using angiography and ultrasonography in patients with Moyamoya disease

OBJECTIVE

Indirect revascularization surgery reduce the risk of recurrent vascular events in patients with moyamoya disease (MMD), but the roles of postoperative angiography and ultrasonography in predicting these events remain unclear.

METHODS

This prospective study enrolled patients with MMD who would undergo their first unilateral indirect revascularization surgery. They received preoperative and postoperative ultrasound examination at 1, 3, and 6 months and conventional cerebral angiography. On ultrasonography, postoperative emerging flow (PEF) in an intracranial artery was defined as emerging flow postoperatively with absence of flow preoperatively. Predictors of vascular event frequency reduction were identified from angiographic and ultrasonographic parameters.

RESULTS

In total, 52 patients (including 24 pediatric and 24 male patients), who underwent 52 preoperative and 82 postoperative ultrasound examinations, were enrolled. Significant postoperative changes were noted in all the ultrasonographic parameters of ipsilateral superficial temporal artery (STA) and the end-diastolic velocity and flow volume in contralateral STA. During a median follow-up of 5.3 years, indirect revascularization surgery significantly reduced the occurrence of ipsilateral vascular events. Predictors of vascular event frequency reduction included Matsushima grade A or B on the ipsilateral side on angiography (odds ratio [OR] = 22.00, P = 0.002) and lower resistance index (RI) in ipsilateral STA (OR = 0.0001, P = 0.012) but no PEF pattern in ipsilateral middle cerebral artery (OR = 0.14, P = 0.029) on ultrasonography performed within 6 months.

CONCLUSIONS

Reduction of long-term vascular event frequency probably can be predicted through postoperative angiography and ultrasonography within 6 months after indirect revascularization surgery.

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 Value of Preoperative Phase-Contrast MRI in Predicting the Clinical Outcome of Moyamoya Disease after Encephalo-Duro-Arterial Synangiosis Surgery

BACKGROUND AND PURPOSE

In patients with Moyamoya disease, the relationship between preoperative hemodynamic status and prognosis after encephalo-duro-arterial synangiosis (EDAS) surgery was unclear. We aimed to explore the value of the preoperative hemodynamic status acquired by cine phase-contrast MR imaging in predicting collateral formation and clinical outcomes after EDAS surgery in patients with Moyamoya disease.

MATERIALS AND METHODS

Participants with Moyamoya disease were prospectively recruited and underwent preoperative phase-contrast MR imaging. All participants were classified into good and poor groups according to the collateral formation after EDAS surgery. On the basis of the change in the mRS system, participants were classified into the improved mRS group and the poor response group. Hemodynamic status including mean velocity, peak velocity, and blood volume flow of the superficial temporal artery was compared between groups. Logistic regression was performed to relate the phase-contrast MR imaging parameters to collateral formation and clinical outcomes.

RESULTS

A total of 45 patients with Moyamoya disease with unilateral EDAS surgery were finally included. Mean velocity, peak velocity, and blood volume flow of the ipsilateral superficial temporal artery were significantly greater in patients with good collateral formation compared with those with poor collateral formation (P = .011, .004, and .013, respectively). The mean velocity, peak velocity, and blood volume flow were independently associated with postoperative collateral formation after adjusting for confounding factors. Furthermore, the peak velocity of the ipsilateral superficial temporal artery was also significantly associated with improvement of the mRS score.

CONCLUSIONS

Good hemodynamic status of the ipsilateral superficial temporal artery as a donor artery evaluated by phase-contrast MR imaging was significantly associated with better collateral formation and improved mRS after EDAS surgery in patients with Moyamoya disease.

Cerebrovascular Reserve Impairment in the Anterior Cerebral Artery Territory Predicts Deep Temporal Artery Enlargement After Combined Revascularization Surgery in Moyamoya Disease

OBJECTIVE

A combined surgery of direct and indirect revascularization has been frequently performed in patients with moyamoya disease, though the efficacy of indirect revascularization surgery in adult patients with moyamoya disease has not been established. This study aimed to evaluate superficial temporal artery (STA) and deep temporal artery (DTA) diameters 1 day and 3 months after combined revascularization surgery in patients with moyamoya disease. We also investigated clinical factors related to DTA enlargement after surgery.

METHODS

We examined 78 cerebral hemispheres in 57 adult and pediatric patients with moyamoya disease who underwent combined revascularization surgery [STA-MCA bypass and encephalo-duro-myo-synangiosis] in our institution. STA and DTA diameters were measured on axial magnetic resonance angiography images at 1 day and 3 months after surgery.

RESULTS

DTA diameter increased in 64 hemispheres (82.1%). DTA diameter increase in association with STA diameter decrease was found in 39 hemispheres (50%). The proportion of hemispheres with a reduction in STA diameter was significantly higher in hemispheres with DTA enlargement than in hemispheres with DTA reduction (P = 0.0088). Among the 64 hemispheres with DTA enlargement, 51 (79.7%) showed cerebrovascular reserve (CVR) impairment in the anterior cerebral artery (ACA) territory before surgery. CVR impairment in the ACA territory was the only clinical factor related to DTA enlargement (P < 0.001).

CONCLUSION

The DTA frequently enlarges after combined revascularization surgery, even in adult patients with moyamoya disease. In patients with impaired CVR in the ACA territory, blood supply from the DTA to the ACA territory can be expected after combined revascularization surgery.

Larger Posterior Revascularization Associated with Reduction of Choroidal Anastomosis in Moyamoya Disease: A Quantitative Angiographic Analysis

BACKGROUND AND PURPOSE

Choroidal anastomosis, a hemorrhage-prone periventricular collateral manifestation in Moyamoya disease, outflows to the cortex posterior to the central sulcus. The objective of the present study was to test whether the angiographic extent of revascularization posterior to the central sulcus contributes to the postoperative reduction of choroidal anastomosis.

MATERIALS AND METHODS

This retrospective cohort study included choroidal anastomosis-positive hemispheres before direct bypass surgery. The postoperative reduction of choroidal anastomosis was determined by a consensus of 2 raters according to the previous research. An imaging software automatically traced the angiographic revascularization area, which was subsequently divided into anterior and posterior parts by an anatomic line corresponding to the central sulcus. Each area was quantitatively measured as a percentage relative to the whole supratentorial area.

RESULTS

Postoperative reduction of choroidal anastomosis was achieved in 68 (85.0%) of the 80 included hemispheres. The revascularization area posterior to the central sulcus was significantly larger in the hemispheres with reduction than in those with no reduction (mean, 15.2% [SD, 7.1%] versus 4.2% [SD, 3.4%], P < .001), whereas no significant difference was observed in the revascularization area anterior to the central sulcus. Multivariate analysis revealed that the revascularization area posterior to the central sulcus was the only significant factor associated with reduction (OR, 1.57; 95% CI, 1.21-2.03, for every 1% increase).

CONCLUSIONS

The results suggest that a larger revascularization posterior to the central sulcus is associated with postoperative reduction of choroidal anastomosis regardless of the extent of anterior revascularization. It might facilitate optimal selection of the revascularization site for preventing hemorrhage.

Baseline Hemodynamic Impairment and Revascularization Outcome in Newly Diagnosed Adult Moyamoya Disease Determined by Pseudocontinuous Arterial Spin Labeling

OBJECTIVE

The study aimed to investigate the hemodynamic features and independent predictors of neoangiogenesis after revascularization in moyamoya disease (MMD) by pseudocontinuous arterial spin labeling magnetic resonance imaging (pCASL MRI).

METHODS

Thirty-nine MMD patients were categorized into infarction group, hemorrhagic group, and atypical group. All patients underwent combined bypass surgery and pCASL MRI with postlabeling delays (PLD) of 1525 ms and 2525 ms. Absolute CBF_MCA (cerebral blood flow in middle cerebral artery territory), relative CBF_MCA (CBF_MCA 2525 ms/CBF_MCA 1525 ms), and spatial coefficient of variation of MCA (CoV_MCA) were analyzed. Relationships between CBF_MCA and the following clinical parameters were assessed: Suzuki stage, modified Rankin scale (mRS), cerebrovascular accident lesion score, and deep medullary veins score. Potential predictors for favorable neoangiogenesis and hemodynamic changes were explored as well.

RESULTS

Preoperative CBF_MCA differed among MMD patients with variable clinical presentations, Matsushima stages, modified Rankin Scale scores, CVA scores, and deep medullary vein scores. After bypass surgery, mean CBF_MCA increased significantly in the infarction group (P = 0.027) and decreased in the hemorrhagic group (P = 0.043), while spatial CoV_MCA was observed to decline in all groups. Higher preoperative relative CBF_MCA and spatial CoV_MCA were independent predictors for robust neoangiogenesis after bypass. The cutoff value of 0.330 of spatial CoV_MCA at long PLD yielded the best sensitivity at 82.1% and specificity at 81.8%. Furthermore, both preoperative relative CBF_MCA and spatial CoV_MCA showed mild positive correlations with ΔmRS in MMD patients.

CONCLUSIONS

pCASL-MRI with multiple PLDs could reflect preoperative hemodynamic impairment and predict the neoangiogenesis after combined bypass surgery in moyamoya patients.

A flow self-regulating superficial temporal artery–middle cerebral artery bypass based on side-to-side anastomosis for adult patients with moyamoya disease

OBJECTIVE

Side-to-side (S-S) superficial temporal artery–middle cerebral artery (STA-MCA) bypass was reportedly used to treat a special moyamoya disease (MMD) patient with collaterals arising from the donor STA. However, the S-S technique is not routinely performed to date, and its benefits are still unknown for adult MMD. The purpose of this study was to investigate the possibility of routine use of the S-S technique for adult MMD.

METHODS

The authors retrospectively analyzed the clinical data of 50 adult patients (65 hemispheres, including 30 in the end-to-side [E-S] group and 35 in the S-S group) with MMD who underwent STA-MCA bypass. The patient demographic characteristics, clinical courses, technical details, intraoperative blood flow data, postoperative and preoperative relative cerebral blood flow (rCBF) values, modified Rankin Scale (mRS) scores, and short-term revascularization results were compared between the 2 groups.

RESULTS

There were no significant differences observed in terms of the baseline characteristics, bypass patency rates, postoperative/preoperative rCBF values, incidence of cerebral hyperperfusion syndrome (CHS), mRS scores, and short-term revascularization results between the 2 groups (all p > 0.05). Intraoperative blood flow analysis showed that the increase of STA flow in the E-S group was significantly higher than that of proximal STA flow in the S-S group (p = 0.008). Although the increases of proximal and distal recipient flow in the E-S group seemed greater than those in the S-S group, the results were not statistically significant (p = 0.086 for proximal flow and p = 0.076 for distal flow). CHS symptoms in the S-S group were milder and with much shorter duration. The follow-up angiographic data of the representative case demonstrated that both frontal and parietal STA branches and the occipital artery participated in postoperative collateralization.

CONCLUSIONS

S-S anastomosis can achieve comparable clinical effects to standard E-S construction. S-S anastomosis used in adult MMD demonstrated mild CHS symptoms with short duration and had the potential to arouse all scalp arteries as donor sources for revascularization through the intact distal STA branch via flow self-regulation.

CT perfusion-based delta-radiomics models to identify collateral vessel formation after revascularization in patients with moyamoya disease

Purpose

To build CT perfusion (CTP)-based delta-radiomics models to identify collateral vessel formation after revascularization in patients with moyamoya disease (MMD).

Methods

Fifty-three MMD patients who underwent CTP and digital subtraction angiography (DSA) examination were retrospectively enrolled. Patients were divided into good and poor groups based on postoperative DSA. CTP parameters, such as mean transit time (MTT), time to drain (TTD), time to maximal plasma concentration (Tmax), and flow extraction product (FE), were obtained. CTP efficacy in evaluating surgical treatment were compared between the good and poor groups. The changes in the relative CTP parameters (ΔrMTT, ΔrTTD, ΔrTmax, and ΔrFE) were calculated to evaluate the differences between pre- and postoperative CTP values. CTP parameters were selected to build delta-radiomics models for identifying collateral vessel formation. The identification performance of machine learning classifiers was assessed using area under the receiver operating characteristic curve (AUC).

Results

Of the 53 patients, 36 (67.9%) and 17 (32.1%) were divided into the good and poor groups, respectively. The postoperative changes of ΔrMTT, ΔrTTD, ΔrTmax, and ΔrFE in the good group were significantly better than the poor group (p < 0.05). Among all CTP parameters in the perfusion improvement evaluation, the ΔrTTD had the largest AUC (0.873). Eleven features were selected from the TTD parameter to build the delta-radiomics model. The classifiers of the support vector machine and k-nearest neighbors showed good diagnostic performance with AUC values of 0.933 and 0.867, respectively.

Conclusion

The TTD-based delta-radiomics model has the potential to identify collateral vessel formation after the operation.

Moyamoya syndrome presenting in an adult with Down syndrome: A case report with a literature review

Moyamoya disease is an unusual occlusive cerebrovascular condition commonly seen in children, marked by stenosis of the internal carotid artery and circle of Willis, causing, cerebral ischemia. Moyamoya syndrome is a Moyamoya-like arteriopathy with risk factors including autoimmune disorders, thyroid disease, sickle cell disease, or Down syndrome. Trisomy 21 is a genetic disorder consistent with specific physical and behavioral characteristics, with intellectual impairment. We describe a rare case of Moyamoya syndrome manifesting as ischemic stroke in an adult with Down syndrome

Surgical revascularization for pediatric moyamoya: the role of surgical mentorship in sustaining and developing a neurovascular service

OBJECTIVE

Obtaining operative experience for the treatment of rare conditions in children represents a challenge for pediatric neurosurgeons. Starting in November 2017, a surgeon was mentored in surgical revascularization (SR) for pediatric moyamoya with a view to service development and sustainability. The aim of this audit was to evaluate early outcomes of SR for pediatric moyamoya during and following a surgical mentorship.

METHODS

A retrospective cohort study with chart/database review of consecutive moyamoya surgeries performed by a new attending surgeon (between November 2017 and March 2020) was compared to a previously published cohort from the authors' institution in terms of clinical and angiographic outcomes, complications, operating time, and length of stay. A standardized technique of encephaloduroarteriomyosynangiosis with the superficial temporal artery was used.

RESULTS

Twenty-two children underwent 36 indirect SRs during the study period. Patient demographics were similar between cohorts. The first group of 6 patients had 11 SRs performed jointly by the new attending surgeon mentored by an established senior surgeon (group A), followed by 10 patients with 16 SRs performed independently by the new attending surgeon (group B). The last 6 patients had 9 SRs with the new attending surgeon mentoring a senior fellow (group C) in performing SR. Good angiographic collateralization (Matsushima grades A and B) was observed in 80% of patients, with similar proportions across all 3 groups. A total of 18/19 symptomatic patients (95%) derived symptomatic benefit. There was no perioperative death and, compared to the historical cohort, a similar proportion had a recurrent arterial ischemic event (i.e., acute ischemic stroke) necessitating a second SR (1/22 vs 3/73). Operative times were longest in group C, with no difference in length of hospital stay among the 3 groups.

CONCLUSIONS

Early outcomes demonstrate the feasibility of mentorship for safely incorporating new neurosurgeons in sustaining and developing a tertiary-level surgical service.

Angiographic, Cerebral Hemodynamic, and Cognitive Outcomes of Indirect Revascularization Surgery Alone for Adult Patients With Misery Perfusion due to Ischemic Moyamoya Disease

BACKGROUND

Revascularization surgery for adult patients with ischemic moyamoya disease (MMD) may improve both cognitive function and cerebral perfusion.

OBJECTIVE

To determine angiographic, cerebral hemodynamic, and cognitive outcomes of indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD (IDR group) and to test the superiority of indirect revascularization surgery for cognitive improvement by conducting comparisons with historical control patients who had undergone direct revascularization surgery (DR group) through prospective cohort study with historical controls.

METHODS

Twenty adult patients with cerebral misery perfusion underwent encephalo-duro-myo-arterio-pericranial-synangiosis alone. Cerebral angiography through arterial catheterization, brain perfusion single-photon emission computed tomography, and neuropsychological testing were performed preoperatively and at 6 months postoperatively.

RESULTS

In 17 patients of the IDR group, collateral flows that were newly formed after surgery on angiograms fed more than one-third of the middle cerebral artery (MCA) cortical territory. In the IDR group, perfusion in the MCA territory was significantly increased after surgery (P < .0001), and the difference in MCA perfusion between before and after surgery was significantly greater (P = .0493) compared with the DR group. Improved cognition was significantly more frequent in the IDR group (65%) than in the DR group (31%, P = .0233).

CONCLUSION

Indirect revascularization surgery alone forms sufficient collateral circulation, improves cerebral hemodynamics, and recovers cognitive function in adult patients with misery perfusion due to ischemic MMD. The latter 2 beneficial effects may be higher when compared with patients undergoing direct revascularization surgery.

Effects of Aspirin Therapy on Bypass Efficacy and Survival of Patients Receiving Direct Cerebral Revascularization

Background: Both patency maintenance and neoangiogenesis contribute to cerebrovascular bypass efficacy. However, the combined impact of the aforementioned two indicators on postoperative revascularization following superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass has been less well elucidated. Meanwhile, there is a paucity of evidence with conflicting results about postoperative aspirin therapy.

Objective: The objective of the study was to investigate the correlation between aspirin use and STA-MCA bypass efficacy, including patency, postoperative neoangiogenesis, and follow-up outcomes.

Methods: A total of 181 MMD patients (201 procedures) undergoing STA-MCA bypass at our institution (2017–2019) were retrospectively reviewed. The bypass efficacy level and postoperative complications were compared between aspirin and non-aspirin groups.

Results: Among 95 PS-matched pairs, the aspirin group presented a significantly more favorable bypass efficacy than the non-aspirin group [odds ratio (OR) 2.23, 95% confidence interval (CI) 1.11–4.61; p = 0.026]. Multivariate logistic regression analysis confirmed the profound impact of aspirin as an independent predictor of bypass efficacy [adjusted OR 2.91, 95% CI 1.34–6.68; p = 0.009]. A remarkable negative correlation was found between bypass efficacy and the rate of ischemic complications (Phi = −0.521). Postoperative aspirin therapy was associated with a non-significant trend toward a lower incidence of ischemic events [OR 0.73, 95% CI 0.23–2.19; p = 0.580]. No significant difference in bleeding rates was observed between aspirin and control groups [OR 1.00, 95% CI 0.12–8.48; p = 1.000].

Conclusion: Among patients undergoing STA-MCA bypass procedures, bypass efficacy is a good predictor of follow-up outcomes. Postoperative aspirin therapy can improve patency, neoangiogenesis, and overall bypass efficacy, thereby protecting against postoperative ischemic complications.

Clinical Trial Registration:http://www.chictr.org.cn/, identifier CTR2100046178.

Caveolin-1 Promoted Collateral Vessel Formation in Patients With Moyamoya Disease

Background

Caveolin-1 (Cav-1) plays pivotal roles in the endothelial function and angiogenesis postischemia. Moyamoya disease (MMD) is characterized by progressive artery stenosis with unknown etiology. We aim to determine whether serum Cav-1 levels of patients with MMD were associated with collateral vessel formation after bypass surgery.

Methods

We studied serum Cav-1 levels of 130 patients with MMD (16 with RNF213 p.R4810K mutation and 114 without RNF213 p.R4810K mutation), 15 patients with acute stroke, and 33 healthy controls. Cerebral perfusion and collateral circulation were evaluated preoperation and at 6 months after operation using pseudocontinuous arterial spin labeling MRI (pCASL-MRI) and digital subtraction angiography (DSA), respectively. Endothelial expression of Cav-1 was verified in the superficial temporal artery (STA) wall of patients with MMD by immunofluorescence double staining. We also investigated whether overexpression of Cav-1 affects cell migration and tube formation using human microvascular endothelial cells (HMECs).

Results

The serum Cav-1 level of patients with MMD intermediated between the stroke group and healthy controls and it was enhanced after the bypass surgery (681.87 ± 311.63 vs. 832.91 ± 464.41 pg/ml, p = 0.049). By 6 months after bypass surgery, patients with MMD with better collateral compensation manifested higher postoperative/preoperative Cav-1 ratio (rCav-1) than bad compensation patients. Consistently, cerebral blood flow (CBF) determined by pCASL-MRI (nCBF_MCA ratio) was positively in line with rCav-1 ratio (r = 0.8615, p < 0.0001). Cav-1 was expressed in the endothelial cells of the STA vessels of patients with MMD. Overexpression of Cav-1 by plasmid transfection in HMECs promoted tube formation and cell migration.

Conclusion

This study indicated that Cav-1 may be a potential driver to promote angiogenesis and collateral formation after bypass surgery in patients with MMD, providing a better understanding of MMD pathophysiology and potential non-surgical targets of MMD.

Recognition of the Effect of Indirect Revascularization for Moyamoya Disease: The Balance Between the Stage Progression and Neoangiogenesis

Objective

To explore the long-term progression of neoangiogenesis after indirect revascularization for moyamoya disease (MMD).

Methods

We enrolled patients who were diagnosed with MMD and treated by encephaloduroarteriosynangiosis (EDAS) surgery at our center from December 2002 through September 2009. A comparative study between short-term (6–12 months) and long-term (duration ≥ 8 years) follow-up angiographies was performed. The development of collateral circulation through EDAS was graded according to the system described by the Matsushima grade system.

Results

A total of 78 patients who received indirect EDAS were enrolled in the study. The mean age at the first operation was 26.9 ± 15.0 years. The Matsushima grades of the same hemisphere were higher at the long-term follow-up compared with the short-term follow-up. Importantly, no attenuation was observed in any hemisphere during the long-term follow-up. In total, 51 hemispheres (32.7%) and 26 hemispheres (16.6%) had progression during the short-term and the long-term follow-up, respectively. The ipsilateral Suzuki stage showed a significant negative correlation with progression pace. Furthermore, higher Suzuki stages were significantly correlated with the postsurgical Matsushima grade at both time points. A total of nine strokes (11.5%) occurred in 78 patients was reported at the long-term follow-up. The annual incidence rate of recurrent strokes was higher for the stage progression group than for the stable group.

Conclusion

For patients with MMD, postsurgical neoangiogenesis after indirect bypass continuously improved with time. The short-term progression of the internal carotid artery (ICA) might be attributed to cerebral revascularization, while the long-term progression should be attributed to the natural progression of the disease.