Limits and pitfalls of indirect revascularization in moyamoya disease and syndrome

A Prospective Study on Hemodynamics of Combined Bypass Surgery in the Treatment of Moyamoya Disease

OBJECTIVE

The study investigates the clinical effectiveness and prognosis of selecting recipient vessels for moyamoya disease (MMD) treatment during combined bypass surgery, focusing on hemodynamic criteria.

METHODS

Ninety-six MMD patients were randomly assigned to 3 groups (A, B, C) of 32 each, undergoing combined bypass surgery. Group A selected the vessel with the fastest fluorescing in the surgical field, group B the slowest, and group C used traditional methods. The authors monitored intraoperative recipient vessel pressure, cerebral blood flow (CBF), and modified Rankin scale (mRS) scores pre-surgery and post-surgery, and compared clinical symptom improvement, stroke recurrence, CBF, and mRS during a 6-month follow-up.

RESULTS

Postoperatively, groups A and B had significantly higher recipient vessel pressures than group C, with group B showing the highest (P<0.05). CBF increased significantly in all groups at 7 days post-surgery and at 6 months, with groups A and B outperforming C, and group B showing the highest increase at 7 days (P<0.05). mRS scores decreased significantly, with groups A and B showing lower scores than C at 6 months (P<0.05). However, group B had a higher incidence of clinical symptoms post-surgery compared with A and C (P<0.05).

CONCLUSION

The study demonstrates that hemodynamic-based recipient vessel selection significantly improves clinical outcomes in MMD patients undergoing combined bypass surgery. Although group B showed the best hemodynamic results, it also had a higher incidence of immediate postoperative symptoms, suggesting a need for a balanced approach to optimize both short-term and long-term patient outcomes.

Impact of Revascularization Timing on Clinical Outcomes of Symptomatic Moyamoya Disease: A Systematic Review and Multivariate Analysis

BACKGROUND AND OBJECTIVES

Despite a substantial body of literature describing the efficacy of revascularization compared with conventional management of moyamoya disease (MMD), the impact of the timing of revascularization relative to stroke onset remains inadequately characterized. The aim of this review was to synthesize existing research to guide clinicians in the optimal timing of revascularization in symptomatic MMD.

METHODS

A comprehensive literature review was performed to identify studies reporting on timing of revascularization. Studies were divided into revascularization within 3 months of stroke, between 3 and 6 months of stroke, or >6 months from stroke event.

RESULTS

A total of 3049 cases and 3151 treated cerebral hemispheres were included. There were 91 individuals (2.98%) in the 3 months to intervention cohort, 152 (4.92%) individuals in the 3 to 6 months to the intervention cohort, and 2806 (92.0%) individuals in the >6 months to the intervention cohort. The average follow-up time was 43.8 ± 35.19 months. Clinical improvement was reported in 83.4% of cases overall. The 3-to-6-month poststroke preoperative interval has the highest frequency of clinical improvement (90.2%), followed by the >6-month preoperative interval (83.4%). The preoperative interval of <3 months had the lowest frequency of clinical improvement (76.5%). Comparison of average treatment effect in the treated demonstrated reduced frequency of improved clinical outcome (Mean difference: -22.6, SE: 9.15, P = .013) and increased frequency of worse clinical outcome (Mean difference: 20.1, SE: 7.38, P = .006) in the <3 months cohort. The >6 months cohort was found to be associated with a reduced frequency of worse clinical outcome (Mean difference -1.81, SE: 0.349, P = .001).

CONCLUSION

The findings of this meta-analysis suggest that, in cases where it is clinically feasible to delay revascularization following an acute neurological event in patients with MMD, postponing intervention is warranted.

Introducing an index on prediction of post-revascularization cerebral infarction using preoperative CT perfusion parameters in moyamoya disease

OBJECTIVE

To determine the value of preoperative CT perfusion (CTP) parameters for prediction of post-revascularization cerebral infarction (post-CI) in adults with moyamoya disease (MMD).

METHODS

This retrospective study included 92 adults with MMD who underwent surgical revascularization. Preoperative quantitative CTP parameters, including cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to drain (TTD), and transit time to maximum of the residue function (Tmax), along with clinical data, were compared between the groups with and without post-CI. Predictors of post-CI were identified and assessed using multivariable logistic regression and receiver-operating characteristic curve analyses.

RESULTS

Post-CI occurred in 11 patients (12.0%). In univariate analysis, preoperative mean values for CBF, MTT, TTD, Tmax, initial presentation, infarction within the 2 months before surgery, surgical side, and modified Rankin Scale score on admission were associated with post-CI (all p < 0.05). Multivariable logistic regression revealed that the preoperative mean Tmax (OR 2.342, 95% CI: 1.267-4.330, p = 0.007) and infarction within the 2 months before surgery (OR 14.345, 95% CI: 2.108-97.638, p = 0.006) were independent predictors of post-CI. The preoperative mean Tmax produced the largest area under the curve (0.955, 95% CI: 0.914-0.997) with a cutoff of 3.590 s (sensitivity, 100%; specificity, 87.7%).

CONCLUSIONS

Adults with MMD are at risk of post-CI when the preoperative mean Tmax is > 3.590 s. Cerebral infarction during the 2 months before revascularization is also a risk factor for post-CI.

CRITICAL RELEVANCE STATEMENT

Post-CI is a serious complication for adults with MMD following surgical revascularization. The risk of post-CI can be predicted using preoperative CTP parameters, which will assist neurosurgeons with surgical decisions and implementing individualized prophylactic strategies.

KEY POINTS

Predicting the risk of post-CI in MMD patients is beneficial to their prognosis. The preoperative mean Tmax was an excellent perfusion parameter for predicting post-CI. Preoperative CTP evaluation can help clinicians make cautious surgical decisions.

Vascular Abnormalities and Neurofibromatosis Type 1: A Paediatric Case Series

Neurofibromatosis type 1 (NF1) is a multisystemic neurocutaneous disease caused by a heterozygous mutation of the NF1 gene that encodes neurofibromin. Complications include vascular and neurologic abnormalities such as moyamoya syndrome, a cerebrovascular disorder with progressive occlusion of the large intracranial arteries, leading to ischemic events and the formation of abnormal vascular networks. Stenosis of the renal artery is another frequent complication of neurofibromatosis type 1, and it represents the most common cause of secondary hypertension in these patients. The purpose of the article is to describe the clinical manifestations of neurofibromatosis type 1 vasculopathy in 4 patients presenting with a wide range of neurologic and reno-vascular manifestations, as well as to examine current diagnostic management and follow-up, current therapeutic options, and to discuss further perspectives in terms of screening, diagnosis, and treatment.

Exploration of the risk factor for infarction after revascularization in moyamoya disease

RESULTS

Eventually, 108 consecutive patients received 174 surgeries were enrolled, experienced new or expanded infarction occured in 13 (7.47%) surgeries, which showed higher Suzuki stage on the non-operative side, more posterior cerebral artery (PCA) involvement, and more intraoperative hypotension compared to those without infarction(p < .05). The Suzuki stage on the non-operative side had the highest area under the curve (AUC) of 0.737, with a sensitivity of 0.692 and specificity of 0.783. Combination of the three factors showed better efficiency, with an AUC of 0.762, a sensitivity of 0.692, and a specificity of 0.907.

CONCLUSIONS

Revascularization was a safe option for patients with MMD, higher Suzuki stage on the non-operative side, PCA involvement, and intraoperative hypotension might be the risk factors for new or expanded infarction after revascularization in patients with MMD.

Role of long non-coding RNAs in neurofibromatosis and Schwannomatosis: pathogenesis and therapeutic potential

Neurofibromatosis (NF) is identified as genetic disorder characterized by multiple tumors on nerve tissues. NF1 is the most prevalent form, identified by neurofibromas and skin changes. NF1 is the most prevalent neurofibromatosis disorder, distinct from the rarer NF2 and schwannomatosis (SWN) conditions. NF2, including NF2-related SWN (NF2-SWN), predominantly involves schwannoma formation and differs from NF1 in its genetic basis and clinical presentation. Despite the established genetic basis of NF, effective treatments remain scarce. Long non-coding RNAs (lncRNAs) have emerged as important regulators of gene expression, impacting pathways vital to tumor biology. This review explores the lncRNAs role in NF pathogenesis along with their potential as therapeutic targets. LncRNAs such as ANRIL and H19 show dysregulated expression in NF, influencing signaling pathways like Ras/MAPK and JAK/STAT, thereby contributing to tumor development. Understanding these interactions sheds light on the molecular mechanisms underlying NF and highlights lncRNAs as potential biomarkers of diagnosis and prognosis of NF. Additionally, therapeutic strategies targeting lncRNAs with antisense oligonucleotides (ASOs) or CRISPR-Cas9 offer promising treatment options. The present review emphasizes crucial role of lncRNAs in NF pathogenesis and their promise to create innovative treatments, aiming to improve patient outcomes and meet the urgent need for effective NF therapies.

Factors affecting the collateral ingrowth from the superficial temporal artery after Encephalo-Duro-Arterio-Synangiosis in adult patients with Moyamoya disease

BACKGROUND

Multiple factors have been proposed to affect the vessel ingrowth from the superficial temporal artery (STA) after Encephalo-Duro-Arterio-Synangiosis (EDAS).

METHODS

This retrospective single-center analyses included patients with Moyamoya Disease (MMD) undergoing EDAS from January 1st, 2013, to December 31st, 2023. Evaluated variables included demographic characteristics, clinical presentation, technical details, modified Rankin Scale (mRS) scores, and radiographic outcomes. Univariate and multivariate analysis was performed to identify factors favoring the ingrowth of collaterals from the STA.

RESULTS

Forty adult patients with MMD, most commonly females (77.5 %) with a median age of 48, underwent 56 EDAS. The most common initial presentations were ischemic events (75.0 %), followed by hemorrhagic events (27.5 %) and seizures (7.5 %). Digital angiography performed at a median of 13.7 months post-procedure revealed collateral growth from the STA in 78.6 % of cases, with a Matsushima grade A identified in 35.7 % of the revascularized hemispheres. Univariate analysis showed more collaterals in patients with a larger preoperative STA diameter (p=0.035), higher Suzuki grades (p=0.021) and longer angiographic follow-ups (p=0.048). Patients with occlusion of the internal carotid artery (ICA; p<0.01), middle cerebral artery (MCA; p<0.01), or anterior cerebral artery (ACA; p<0.01) also had more collateral ingrowth. Multivariate analysis revealed that ICA occlusion (OR=6.54; 95 % CI=1.03-41.48) and ACA occlusion (OR=6.52; 95 % CI=1.02-41.67) as predictors of collateral ingrowth from the STA.

CONCLUSION

ICA and ACA occlusion were associated with success after EDAS. Longer follow-ups and larger STA demonstrated significant association on univariate analysis, but lost significance after adjusting for other procedural characteristics.

Characterizing Revascularization After Encephalo-Duro-Arterio-Synangiosis (EDAS) in Adult Patients With Moyamoya Disease Using the Orbital Grading System

BACKGROUND

The Matsushima grade has traditionally been used to evaluate vessel ingrowth from the superficial temporal artery after encephalo-duro-arterio-synangiosis (EDAS) for Moyamoya disease (MMD) patients. However, this grading is subjective and prone to measurement variability. Herein, we propose the orbital grading system quantifying leptomeningeal and burr hole-related vessel-ingrowth from the superficial temporal artery and/or middle meningeal artery to the middle and anterior cerebral arteries post EDAS in MMD patients.

METHODS

An anatomical classification was developed by reference to 2 parallel vertical lines from the bony landmarks of the orbit, categorized from Grade 0-3. Regression models were used to compare clinical and functional outcomes of our grading system with the Matsushima scale.

RESULTS

Forty MMD patients, with median age of 48 years, mostly females (72.5%), underwent 56 EDAS procedures. Presentation included ischemic events (65.0%), hemorrhage (22.5%), and seizures (7.5%). Most patients were categorized as Suzuki ≥ IV (69.5%). Fifty EDAS (89.9%) had concurrent burr holes placed (parietal and frontal regions). At a median follow-up of 13.7 months, collateral growth was graded as follows: grade 0 (6; 10.8%), grade 1 (12; 21.4%), grade 2 (23; 41.1%), and grade 3 (15; 26.8%). Linear regression showed similarities in the distribution between the orbital grading system and Matsushima grading (r = 0.86; P < 0.01). Ischemic events were fewer in hemispheres categorized as grade 2-3 compared to grade 0-1 (P = 0.047) as well as in Matsushima grading A or B compared to C (P = 0.047).

CONCLUSIONS

The orbital grading system demonstrated agreement in identifying postoperative ischemic events as the Matsushima grade and provides a more practical and objective evaluation of collateral vessel ingrowth after EDAS with and without burr holes.

Comprehensive Serum Proteomic and Metabolomic Profiles of Pediatric Patients with Moyamoya Disease Reveal Core Pathways

Background

Moyamoya disease (MMD) signifies a cerebrovascular disorder with obscure origin and a more rapid and severe progression in children than adults. This investigation aims to uncover age-associated distinctions through proteomic and metabolomic profiling to gain insights into the underlying mechanisms of MMD.

Methods

Twelve MMD patients-six children and six adults-along with six healthy controls (HC), participated, each providing a 10 mL blood sample. Serum proteomic and metabolomic analyses were conducted using ultra-performance liquid chromatography and high-resolution mass spectrometry, complemented by bioinformatics to identify differential biomolecules and their interactions. Pathway implications were ascertained using GO and KEGG enrichment analysis.

Results

Notable proteomic and metabolomic discrepancies were observed between pediatric and adult MMD subjects. A total of 235 and 216 proteins varied in adult and pediatric cases compared to HCs, with 73 proteins shared. In addition, 129 and 74 anionic, plus 96 and 104 cationic metabolites, were differentially expressed in the pediatric and adult groups, respectively, with 34 anionic and 28 cationic metabolites in common. Age-specific biomolecules further characterized these distinctions. Enrichment analysis pinpointed immunity and inflammation pathways, with vitamin digestion and absorption highlighted as pivotal in pediatric MMD.

Conclusion

This study unveils distinct metabolic and proteomic patterns within pediatric and adult MMD patients. The critical role of the vitamin digestion and absorption pathway in the pathogenesis of pediatric MMD offers novel insight into disease mechanisms.

Case Report: A rare presentation of rapidly progressive moyamoya disease refractory to unilateral surgical revascularization

Moyamoya disease (MMD) is a chronic, occlusive cerebrovasculopathy typified by progressive steno-occlusive disease of the intracranial internal carotid arteries (ICAs) and their proximal branches. Moyamoya syndrome (MMS) categorizes patients with characteristic MMD plus associated conditions. As such, the most usual presentations are those that occur with cerebral ischemia, specifically transient ischemic attack, acute ischemic stroke, and seizures. Hemorrhagic stroke, headaches, and migraines can also occur secondary to the compensatory growth of fragile collateral vessels propagated by chronic cerebral ischemia. While the pathophysiology of MMD is unknown, there remain numerous clinical associations including radiation therapy to the brain, inherited genetic syndromes, hematologic disorders, and autoimmune conditions. We describe the case of a 31-year-old woman who presented with recurrent ischemic cerebral infarcts secondary to rapidly progressive, bilateral MMD despite undergoing early unilateral surgical revascularization with direct arterial bypass. She had numerous metabolic conditions and rapidly decompensated, ultimately passing away despite intensive and aggressive interventions. The present case highlights that progression of moyamoya disease to bilateral involvement can occur very rapidly, within a mere 6 weeks, a phenomenon which has not been documented in the literature to our knowledge.

Novel analysis of functional relationship linking moyamoya disease to moyamoya syndrome

Objective

The aim of this study was to elucidate the genetic pathways associated with Moyamoya disease (MMD) and Moyamoya syndrome (MMS), compare the functional activities, and validate relevant related genes in an independent dataset.

Methods

We conducted a comprehensive search for genetic studies on MMD and MMS across multiple databases and identified related genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichments analyses were performed for these genes. Commonly shared genes were selected for further validation in the independent dataset, GSE189993. The Sangerbox platform was used to perform statistical analysis and visualize the results. P＜0.05 indicated a statistically significant result.

Results

We included 52 MMD and 51 MMS-related publications and identified 126 and 51 relevant genes, respectively. GO analysis for MMD showed significant enrichment in cytokine activity, cell membrane receptors, enzyme binding, and immune activity. A broader range of terms was enriched for MMS. KEGG pathway analysis for MMD highlighted immune and cellular activities and pathways related to MMS prominently featured inflammation and metabolic disorders. Notably, nine overlapping genes were identified and validated. The expressions of RNF213, PTPN11, and MTHFR demonstrated significant differences in GSE189993. A combined receiver operating characteristic curve showed high diagnostic accuracy (AUC = 0.918).

Conclusions

The findings indicate a close relationship of MMD with immune activity and MMS with inflammation, metabolic processes and other environmental factors in a given genetic background. Differentiating between MMD and MMS can enhance the understanding of their pathophysiology and inform the strategies for their diagnoses and treatment.

Surgical revascularization as a procedure to prevent neurological complications in children with moyamoya syndrome associated with neurofibromatosis I: a single institution case series

BACKGROUND

The optimal timing and surgical approach for surgical revascularization in patients with moyamoya syndrome (MMS) associated with neurofibromatosis type I (NF1) remain so far elusive. We aimed to compare the long-term clinical, radiological, and cognitive effects of different revascularization procedures in a pediatric cohort of NF1-associated MMS.

METHODS

We reviewed the clinical, radiological, and surgical data of 26 patients with NF1-associated MMS diagnosed at our institution between 2012 and 2022, at the clinical onset and last follow-up.

RESULTS

Indirect bypasses were performed in 12/26 patients (57.1%), while combined direct and indirect procedures in 9/26 subjects (42.9%); 5 patients did not undergo surgery. Through logistic regression analysis, pathological Wechsler Intelligence Scale for Children (WISC) at onset was found to be associated with symptom improvement at 1-year follow up (p = 0.006). No significant differences were found in long-term neurocognitive outcome and stroke rate in patients receiving combined or indirect bypass (p > 0.05).

CONCLUSIONS

Currently, whether combined or indirect bypass should be considered the treatment of choice in pediatric patients with NF1-associated MMS remains unclear, as well as the optimal time approach. In our series, no significant differences were found in long-term neurocognitive outcome and stroke rate between patients treated with either of these two approaches. Clinical evidence supports the crucial role of early diagnosis and surgical revascularization in subjects with MMS-associated NF1, even in case of mildly symptomatic vasculopathy. This allows to achieve a good long-term outcome with improved intellectual function and prevention of stroke and seizure in these patients.

Neuropsychiatric Symptoms of Moyamoya Disease: Considerations for the Clinician

Neurocognitive impairment in moyamoya disease is common, under recognized, and potentially devastating. The purpose of this paper is to provide an updated overview on this topic for the practicing clinician. We searched PubMed for keywords including cognitive impairment, neurocognitive dysfunction, and neuropsychological recovery in moyamoya disease. We summarized the literature to provide a concise review of the treatment and management of neuropsychiatric symptoms associated with moyamoya disease. Neuropsychiatric sequelae have conventionally been attributed to chronic cerebral hypoperfusion and/or stroke. Cognitive dysfunction in adults with moyamoya disease is most commonly in the form of impaired executive function, whereas intelligence is the predominant impairment in children with moyamoya disease. Pharmacotherapy for treatment of the neuropsychiatric symptoms associated with moyamoya disease is appropriate and can improve quality of life; however, careful consideration is needed to avoid adverse cerebrovascular events. It remains unclear as to whether surgical revascularization improves or stabilizes cognitive performance and outcomes. Additional prospective studies are warranted to better understand the long-term impact of revascularization on cognitive functioning in moyamoya disease.

Future of Endovascular and Surgical Treatments of Atherosclerotic Intracranial Stenosis

Intracranial atherosclerotic disease and resultant intracranial stenosis is a global leading cause of stroke, and poses an ongoing treatment challenge. Among patients with intracranial stenosis, those with hemodynamic compromise are at high risk for recurrent stroke despite medical therapy and risk factor modification. Revascularization of the hypoperfused territory is the most plausible treatment strategy for these high-risk patients, yet surgical and endovascular therapies have not yet shown to be sufficiently safe and effective in randomized controlled trials. Advances in diagnostic and therapeutic technologies have led to a resurgence of interest in surgical and endovascular treatment strategies, with a growing body of evidence to support their further evaluation in the treatment of select patient populations. This review outlines the current and emerging endovascular and surgical treatments and highlights promising future management strategies.

Reconstruction of Scalp Defects Using Rotational Flaps After Revascularization Surgery in Patients with Moyamoya Disease

OBJECTIVE

Treating scalp defects after revascularization surgery is difficult because the scalp microcirculation is severely compromised. We aimed to review the clinical effects of using rotational flaps in scalp defect reconstruction and explore risk factors for wound-related complications (WRC) after reconstruction surgery.

METHODS

We retrospectively identified patients with scalp defects after combined revascularization surgery who were surgically treated with rotational flap reconstruction at our institution between January 2018 and December 2022. We analyzed treatment results in different surgical technique and revascularization strategy cohorts, including direct bypass superficial temporal artery branch selection, indirect bypass types, and skin incisions.

RESULTS

Eleven patients were included. The superficial temporal artery parietal branch was selected for direct bypass surgery in 10 (90.9%) patients, 4 (40%) of whom had WRC after flap reconstruction. Five types of indirect bypass surgeries were performed; three patients treated by encephalo-duro-myo-arterio-perio-synangiosis and 1 patient treated by encephalo-duro-myo-perio-synangiosis had WRC after flap reconstruction. Question mark (n = 6, 54.5%), curved (n = 4, 36.65%), and Y-shaped (n = 1, 9.1%) incisions were used; in the first three incision cohorts, 2 patients in each cohort had WRC after flap reconstruction.

CONCLUSIONS

Patients had the following commonalities that may be risk factors for WRC after flap reconstruction: 1) wounds with nonviable bone exposure after revascularization surgery; 2) three or more tissues used as donor tissues and donor tissues containing the periosteum; and 3) thin scalp around the defect.

Clinical effect of a modified superficial temporal artery-middle cerebral artery bypass surgery in Moyamoya disease treatment

Background

Cerebral extracranial-intracranial (EC-IC) revascularization technique (superficial temporal artery-middle cerebral artery (STA-MCA) bypass grafting) has become the preferred surgical method for the treatment of Moyamoya disease (MMD). We attempted to completely free the two branches of the superficial temporal artery without disconnection. Extracranial and intracranial blood flow reconstruction were then modified by selectively performing a direct bypass technique on one branch and a patch fusion technique on the other of the STA based on the blood flow and the vascular diameter of the intracranial surface blood vessels.

Methods

A series of modified STA-MCA bypass surgeries performed consecutively between March 2022 and March 2023 were reviewed and compared to conventional combined bypass surgeries performed during the same period. The following information was collected from all enrolled patients: demographic characteristics, clinical symptoms, and preoperative and postoperative imaging, including Suzuki stage and Matsushima grade. The modified Rankin scale (mRS) was used to assess the changes in neurological status before and after surgery.

Results

A total of 41 patients with Moyamoya disease (MMD) who underwent cerebral revascularization were included in this study, of which 30 were conventional revascularization and 11 were modified revascularization. The mean age was 49.91 years, and 18 (43.9%) of the patients were women. The modified group had a lower incidence of cerebral hyperperfusion syndrome (18.2%) than the conventional group (23.3%). After at least 3 months of follow-up, the bypass patency rate remained 100% in the modified group and 93.3% in the conventional group. All patients in the modified group achieved a better Matsushima grade (A + B), with six (54.5%) having an A and five (45.5%) having a B. In contrast, four patients (13.3%) in the conventional group had a Matsushima grade of C. In all, 72.8% of the modified group had postoperative mRS scores of 0 and 1, which was higher than that of the traditional group (63.3%).

Conclusion

The improved STA-MCA bypass could provide blood flow to multiple cerebral ischemic areas, reduce excessive blood perfusion, and ensure blood supply to the scalp, with lower complications and better clinical benefits than the traditional combined bypass.

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.

Moyamoya Vasculopathy in Neurofibromatosis Type 1 Pediatric Patients: The Role of Rare Variants of RNF213

Neurofibromatosis type 1 (NF1) is a neurocutaneous disorder caused by mutations in NF1 gene, coding for neurofibromin 1. NF1 can be associated with Moyamoya disease (MMD), and this association, typical of paediatric patients, is referred to as Moyamoya syndrome (MMS). MMD is a cerebral arteriopathy characterized by the occlusion of intracranial arteries and collateral vessel formation, which increase the risk of ischemic and hemorrhagic events. RNF213 gene mutations have been associated with MMD, so we investigated whether rare variants of RNF213 could act as genetic modifiers of MMS phenotype in a pediatric cohort of 20 MMS children, 25 children affected by isolated MMD and 47 affected only by isolated NF1. By next-generation re-sequencing (NGS) of patients' DNA and gene burden tests, we found that RNF213 seems to play a role only for MMD occurrence, while it does not appear to be involved in the increased risk of Moyamoya for MMS patients. We postulated that the loss of neurofibromin 1 can be enough for the excessive proliferation of vascular smooth muscle cells, causing Moyamoya arteriopathy associated with NF1. Further studies will be crucial to support these findings and to elucidate the possible role of other genes, enhancing our knowledge about pathogenesis and treatment of MMS.

Outcomes after superficial temporal artery–middle cerebral artery anastomosis combined with multiple burr hole surgery and dural inversion synangiosis for moyamoya disease in adults

Objective

Several forms of cerebral revascularization have been carried out to treat moyamoya disease, however, the existing methods are accompanied by a variety of complications. In this study, the authors aimed to evaluate the clinical and angiographic outcomes of a new surgical procedure: superficial temporal artery–middle cerebral artery (STA-MCA) anastomosis combined with multiple burr hole (MBH) surgery and dural inversion synangiosis for the treatment of moyamoya disease in adults.

Methods

Patients treated for moyamoya disease from August 2019 to July 2021 were retrospectively reviewed. Clinical data, including perioperative complications and follow-up outcomes, were noted. Preoperative and postoperative angiograms were compared, and the diameters of the frontal branch of the superficial temporal artery (F-STA), the deep temporal artery (DTA), the distal superficial temporal artery (STA) before the bifurcation and the middle meningeal artery (MMA) were measured on preoperative and postoperative angiograms. Meanwhile, a Matsushima score was assigned from postoperative angiograms.

Results

This study included 66 patients (67 hemispheres). During the follow-up period, a median of 18 (IQR, 13–21) months, no stroke or death occurred in any of the patients. The clinical outcomes were excellent in 27 patients (40.9%), good in 34 patients (51.6%), fair in 4 patients (6.0%), and poor in 1 patient (1.5%); the overall rate of favorable clinical outcomes (excellent and good) was 92.5%. The modified Rankin Scale (mRS) score was significantly improved at follow-up (P < 0.001). There were 41 hemispheres imaged by cerebral angiography after the operation, at a median postoperative interval of 9 (IQR, 8–12) months; among them, 34 (82.9%) hemispheres had Matsushima scores of grade A and grade B. The average postoperative diameters in the STA, DTA and MMA were increased significantly in 41 hemispheres at follow-up (P < 0.001). Sixteen (24.2%) patients suffered from perioperative complications, including focal hyperperfusion syndrome (HS) in 8 (12.2%) patients, cerebral infarction in 3 (4.5%) patients (including one case accompanied by wound infection), cerebral hemorrhage in 2 (3.0%) patients, seizures in 2 (3.0%) patients, and subdural effusion in 1 (1.5%) patient.

Conclusions

The procedure of STA-MCA anastomosis combined with MBH surgery and dural inversion synangiosis may be a safe and effective treatment for adult patients with moyamoya disease.

Modified pedicled temporoparietal fascial flap combined revascularization in adult moyamoya angiopathy

Background

Pedicled temporoparietal fascial flaps (TPFF), which are flexible, thin, and highly vascularized, have been tried for the moyamoya angiopathy (MMA) treatment. To reduce postoperative complications and improve prognosis, we performed surgical modification and followed up to observe the efficacy.

Methods

From February 2018 and June 2022, the clinical data of 31 adult MMA patients who underwent the modified TPFF combined revascularization were collected. The clinical outcomes and complications of the patients were recorded until the cut-off date of follow-up. The primary endpoints were the magnetic resonance perfusion (MRP), modified Rankin Scale (mRS) scores, and Matsushima Grade; the secondary endpoints were the clinical symptom outcome and Postoperative complications. Descriptive statistics and rank sum test to assess the therapeutic effect of the modified TPFF combined revascularization for adult MMA treatment.

Results

The clinical symptoms of MMA were alleviated in 26 patients and disappeared in five. In all patients, MRP showed improvement in cerebral perfusion on the operated side, and no deterioration or new cerebral infarction occurred during follow-up. Postoperative digital subtraction angiography (DSA) showed that the anastomotic site was patent, and the MMA collateral was decreased in all patients. Only 1 case (3%) of Matsushima grade C showed poor collateral compensation. The admission mRS score (1.54±0.66) of the ischemic MMA was significantly reduced compared with ≥6 months postoperatively (0.54±0.72, P<0.01). The admission mRS score (0.57±0.53) of the hemorrhagic MMA was reduced compared with ≥6 months postoperatively (0, P<0.05). Postoperative complications included epileptic seizures in 2 cases, a cerebral hyper-perfusion syndrome in 2 cases, intracranial rebleeding in 2 cases, skin necrosis in 1 case, and skin maceration in 1 case.

Conclusions

Modified TPFF combined revascularization might be a feasible and safe surgical technique for MMA, but it is still necessary to increase the sample size and extend the follow-up time to evaluate its efficacy. Ischemic MMA may have a more significant prognostic benefit than hemorrhagic MMA by this surgery.

Surgical techniques and indications for treatment of adult moyamoya disease

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

Mystery(n) Phenotypic Presentation in Europeans: Report of Three Further Novel Missense RNF213 Variants Leading to Severe Syndromic Forms of Moyamoya Angiopathy and Literature Review

Moyamoya angiopathy (MMA) is a rare cerebral vasculopathy in some cases occurring in children. Incidence is higher in East Asia, where the heterozygous p.Arg4810Lys variant in RNF213 (Mysterin) represents the major susceptibility factor. Rare variants in RNF213 have also been found in European MMA patients with incomplete penetrance and are today a recognized susceptibility factor for other cardiovascular disorders, from extracerebral artery stenosis to hypertension. By whole exome sequencing, we identified three rare and previously unreported missense variants of RNF213 in three children with early onset of bilateral MMA, and subsequently extended clinical and radiological investigations to their carrier relatives. Substitutions all involved highly conserved residues clustered in the C-terminal region of RNF213, mainly in the E3 ligase domain. Probands showed a de novo occurring variant, p.Phe4120Leu (family A), a maternally inherited heterozygous variant, p.Ser4118Cys (family B), and a novel heterozygous variant, p.Glu4867Lys, inherited from the mother, in whom it occurred de novo (family C). Patients from families A and C experienced transient hypertransaminasemia and stenosis of extracerebral arteries. Bilateral MMA was present in the proband’s carrier grandfather from family B. The proband from family C and her carrier mother both exhibited annular figurate erythema. Our data confirm that rare heterozygous variants in RNF213 cause MMA in Europeans as well as in East Asian populations, suggesting that substitutions close to positions 4118–4122 and 4867 of RNF213 could lead to a syndromic form of MMA showing elevated aminotransferases and extracerebral vascular involvement, with the possible association of peculiar skin manifestations.

A rare triad of morning glory disc anomaly, moyamoya vasculopathy, and transsphenoidal cephalocele: pathophysiological considerations and surgical management

Morning glory disc anomaly is a congenital abnormality of the optic disc and peripapillary retina reported as an isolated condition or associated with various anomalies, including basal encephaloceles and moyamoya vasculopathy. However, the co-occurrence of these three entities is extremely rare and the pathogenesis is still poorly understood. Moreover, data on the surgical management and long-term follow-up of the intracranial anomalies are scarce. Here, we describe the case of a 11-year-old boy with morning glory disc anomaly, transsphenoidal cephalocele, and moyamoya vasculopathy, who underwent bilateral indirect revascularization with encephalo-duro-myo-arterio-pericranio-synangiosis at the age of 2 years, and endoscopic repair of the transsphenoidal cephalocele at the age of 6 years. A rare missense variant (c.1081T>C,p.Tyr361His) was found in OFD1, a gene responsible for a X-linked ciliopathy, the oral-facial-digital syndrome type 1 (OFD1; OMIM 311200). This case expands the complex phenotype of OFD1 syndrome and suggests a possible involvement of OFD1 gene and Shh pathway in the pathogenesis of these anomalies.