Encephaloduroarteriosynangiosis for hemorrhagic moyamoya disease: long-term outcome of a consecutive series of 95 adult patients from a single center

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.

The Characteristics of Extracranial Internal Carotid Artery and Their Relationship With Surgical Outcomes in Patients With Moyamoya Disease: A Combined Head-and-Neck Vessel Wall MR Imaging Study

BACKGROUND

The features of intracranial arteries in patients with Moyamoya disease (MMD) have been widely investigated. However, the MR characteristics of extracranial internal carotid artery (EICA) and their effect on outcomes of revascularization treatment are not fully understood.

PURPOSE

To investigate the characteristics of EICA and their relationship with outcomes of revascularization treatment in adult patients with MMD based on higher-resolution MRI (HRMRI).

STUDY TYPE

Prospective interventional outcomes.

SUBJECTS

Two hundred eighty-eight consecutive patients with MMD (mean age: 43.7 ± 11.2 years; 140 male).

FIELD STRENGTH/SEQUENCE

Turbo inversion recovery magnitude T1-weighted imaging and turbo spin echo (TSE) T2-weighted imaging, three-dimensional time-of-flight MR angiography, T2-fluid attenuated inversion recovery, and 3D T1-SPACE vessel wall imaging at 3.0 T.

ASSESSMENT

The HRMRI characteristics of EICA were determined. The relationship between the characteristics of EICA (proximal stenosis, diffuse wall thickening, carotid plaques, and luminal thrombosis) and stroke outcomes of revascularization treatment in patients with MMD was analyzed. The discriminative ability of EICA characteristics in combination with intracranial carotid artery features (involvement of vessel segments, bilateral involvement, and Suzuki stage) to determine stroke outcomes was compared with that of intracranial artery features alone during a mean 8.0 months follow-up period.

STATISTICAL TESTS

Cox proportional hazards models and Kaplan-Meier curves to calculate the hazard ratios (HRs) for stroke with 95% confidence intervals (CIs). Area under the receiver operating characteristic curve (AUC) for assessing discriminative performance. A P value <0.05 was considered statistically significant.

RESULTS

During a mean 8.0 ± 2.2 months follow-up, of the 288 participants, 137 had proximal stenosis (47.6%), 106 had diffuse wall thickening (36.8%), 60 had carotid plaques (20.8%), and 27 had luminal thrombosis (9.4%) of EICA. Of these features, proximal stenosis (HR = 2.86; 95% CI = 1.13-7.29) and diffuse wall thickening (HR = 2.62; 95% CI = 1.16-5.94) of EICA were significantly associated with stroke after surgery, before and after adjusting for confounding factors. In discriminating the stroke outcomes after surgery, combining characteristics of EICA with features of intracranial arteries resulted in a significant incremental improvement (DeLong test, P < 0.05) in the AUC over that obtained with features of intracranial arteries alone (AUC: 0.73 vs. 0.60-0.64).

CONCLUSION

Proximal stenosis and diffuse wall thickening of EICA were significantly associated with stroke outcomes after surgery in patients with MMD. Our findings suggest that understanding the characteristics of EICA has added value for intracranial vessels in predicting future events after surgery in patients with MMD.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 4.

Surgical outcomes following encephaloduroarteriosynangiosis in moyamoya disease associated with hyperhomocysteinemia

INTRODUCTION

This study investigated the effect of indirect revascularization surgery in adult patients with moyamoya disease (MMD) complicated with hyperhomocysteinemia (HHcy), and the effect of HHcy on the progression of adult MMD.

METHODS

A retrospective case-control study was conducted in patients with MMD, with or without HHcy (n = 123). Postoperative collateral angiogenesis was evaluated using the Matsushima grading system and disease progression using the Suzuki staging system. Cerebral blood flow was evaluated before and after surgery using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) and neurological function prognosis using the improved Rankin score (mRS). Univariate and multivariate logistic regression analyses were performed to determine risk factors for the clinical outcomes.

RESULTS

There was no significant difference in the Suzuki stage composition ratios between the HHcy group and the non-HHcy group before and after surgery. Non-HHcy patients were more likely to grow new collateral circulating vessels after encephaloduroarteriosynangiosis (EDAS). Moreover, postoperative DSC-MRI indicated that the time to peak significantly improved.

CONCLUSIONS

HHcy level may be a specific predictor of adverse clinical outcomes after EDAS in patients with MMD and a risk factor for poor collateral circulation and poor prognosis. Patients with MMD complicated with HHcy need to strictly control homocysteine levels before EDAS surgery.

Physiological and pathophysiological mechanisms of the molecular and cellular biology of angiogenesis and inflammation in moyamoya angiopathy and related vascular diseases

Rationale

The etiology and pathophysiological mechanisms of moyamoya angiopathy (MMA) remain largely unknown. MMA is a progressive, occlusive cerebrovascular disorder characterized by recurrent ischemic and hemorrhagic strokes; with compensatory formation of an abnormal network of perforating blood vessels that creates a collateral circulation; and by aberrant angiogenesis at the base of the brain. Imbalance of angiogenic and vasculogenic mechanisms has been proposed as a potential cause of MMA. Moyamoya vessels suggest that aberrant angiogenic, arteriogenic, and vasculogenic processes may be involved in the pathophysiology of MMA. Circulating endothelial progenitor cells have been hypothesized to contribute to vascular remodeling in MMA. MMA is associated with increased expression of angiogenic factors and proinflammatory molecules. Systemic inflammation may be related to MMA pathogenesis.

Objective

This literature review describes the molecular mechanisms associated with cerebrovascular dysfunction, aberrant angiogenesis, and inflammation in MMA and related cerebrovascular diseases along with treatment strategies and future research perspectives.

Methods and results

References were identified through a systematic computerized search of the medical literature from January 1, 1983, through July 29, 2022, using the PubMed, EMBASE, BIOSIS Previews, CNKI, ISI web of science, and Medline databases and various combinations of the keywords "moyamoya," "angiogenesis," "anastomotic network," "molecular mechanism," "physiology," "pathophysiology," "pathogenesis," "biomarker," "genetics," "signaling pathway," "blood-brain barrier," "endothelial progenitor cells," "endothelial function," "inflammation," "intracranial hemorrhage," and "stroke." Relevant articles and supplemental basic science articles almost exclusively published in English were included. Review of the reference lists of relevant publications for additional sources resulted in 350 publications which met the study inclusion criteria. Detection of growth factors, chemokines, and cytokines in MMA patients suggests the hypothesis of aberrant angiogenesis being involved in MMA pathogenesis. It remains to be ascertained whether these findings are consequences of MMA or are etiological factors of MMA.

Conclusions

MMA is a heterogeneous disorder, comprising various genotypes and phenotypes, with a complex pathophysiology. Additional research may advance our understanding of the pathophysiology involved in aberrant angiogenesis, arterial stenosis, and the formation of moyamoya collaterals and anastomotic networks. Future research will benefit from researching molecular pathophysiologic mechanisms and the correlation of clinical and basic research results.

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.

The Potential Mechanism Behind Native and Therapeutic Collaterals in Moyamoya

Background and Purpose

To explore the genetic basis and molecular mechanism of native arteriogenesis and therapeutic synangiosis in moyamoya disease (MMD).

Methods

An angiography-based study using patients from a prospective trial of encephaloduroarteriosynangiosis (EDAS) surgery was performed. The spontaneous collaterals grades were evaluated according to the system described by a new grading system. Blood samples were collected from all the recruited patients before EDAS and during the second hospitalization 3 months post-EDAS. We performed Boolean analysis using a combination of specific cell surface markers of CD34^briCD133⁺CD45^dimKDR⁺. Genotyping of p.R4810K was also performed. The correlation of age, sex, initial symptoms at diagnosis, collateral grade, Suzuki stages, the RNF213 genotype, time to peak (TTP), and endothelial progenitor cell (EPC) count with good collateral circulation was evaluated.

Results

Eighty-five patients with MMD were included in this study. The mutation rate of RNF213 p.R4810K in our study was 25.9% (22/85). The heterozygous mutations were occurred significantly more frequently in the cases that were presented with infarction, worse neurological status, severe posterior cerebral artery (PCA) stenosis, and longer TTP delay. Further, the heterozygous mutations occurred significantly more frequently in the poor collateral stage group. Lower grades were significantly correlated with severe ischemia symptoms, worse neurological status, and a longer TTP delay. The post-operative angiographic findings showed that a good Matsushima grade was correlated with heterozygous mutations, a lower collateral stage, and a longer TTP delay. The CD34^briCD133⁺CD45^dimKDR⁺ cell count in patients 3 months post-EDAS was significantly higher as compared to the count before EDAS in the good Matsushima grade group. However, this change was not observed in the poor Matsushima grade group.

Conclusions

These data imply that mutations of RNF213 p.R4810K affect the establishment of spontaneous collateral circulation, and EPCs are involved in the process of formation of new EDAS collaterals.

Daily Remote Ischemic Conditioning Can Improve Cerebral Perfusion and Slow Arterial Progression of Adult Moyamoya Disease—A Randomized Controlled Study

Background and Purpose

Moyamoya disease (MMD) is a complicated cerebrovascular disease with recurrent ischemic or hemorrhagic events. This study aimed to prove the safety and efficacy of remote ischemic conditioning (RIC) on MMD.

Methods

In total, 34 patients with MMD participated in this pilot, prospective randomized controlled study for 1 year. 18 patients were allocated into the RIC group, and 16 patients accepted routine medical treatment only. RIC-related adverse events were recorded. The primary outcome was the improvement ratio of mean cerebral blood flow (mCBF) in middle cerebral artery territory measured by multidelay pseudocontinuous arterial spin labeling, and the secondary outcomes were the cumulative incidence of major adverse cerebrovascular events (MACEs), the prevalence of stenotic-occlusive progression, and periventricular anastomosis at 1-year follow-up.

Results

In total, 30 of the 34 patients with MMD completed the final follow-up (17 in the RIC group and 13 in the control group). No adverse events of RIC were observed. The mCBF improvement ratio of the RIC group was distinctively higher compared with the control group (mCBF−whole-brain: 0.16 ± 0.15 vs. −0.03 ± 0.13, p = 0.001). Stenotic-occlusive progression occurred in 11.8% hemispheres in the RIC group and 38.5% in the control group (p = 0.021). The incidence of MACE was 5.9% in the RIC group and 30.8% in the control group (hazard ratio with RIC, 0.174; 95% CI, 0.019–1.557; p = 0.118). No statistical difference was documented in the periventricular anastomosis between the two groups after treatment.

Conclusions

Remote ischemic conditioning has the potential to be a safe and effective adjunctive therapy for patients with MMD largely due to improving cerebral blood flow and slowing the arterial progression of the stenotic-occlusive lesions. These findings warrant future studies in larger trials.

Macrohistory of Moyamoya Disease Analyzed Using Artificial Intelligence

INTRODUCTION

Moyamoya disease is characterized by progressive stenotic changes in the terminal segment of the internal carotid artery and the development of abnormal vascular networks called moyamoya vessels. The objective of this review was to provide a holistic view of the epidemiology, etiology, clinical findings, treatment, and pathogenesis of moyamoya disease. A literature search was performed in PubMed using the term "moyamoya disease," for articles published until 2021.

RESULTS

Artificial intelligence (AI) clustering was used to classify the articles into 5 clusters: (1) pathophysiology (23.5%); (2) clinical background (37.3%); (3) imaging (13.2%); (4) treatment (17.3%); and (5) genetics (8.7%). Many articles in the "clinical background" cluster were published from the 1970s. However, in the "treatment" and "genetics" clusters, the articles were published from the 2010s through 2021. In 2011, it was confirmed that a gene called Ringin protein 213 (RNF213) is a susceptibility gene for moyamoya disease. Since then, tremendous progress in genomic, transcriptomic, and epigenetic profiling (e.g., methylation profiling) has resulted in new concepts for classifying moyamoya disease. Our literature survey revealed that the pathogenesis involves aberrations of multiple signaling pathways through genetic mutations and altered gene expression.

CONCLUSION

We analyzed the content vectors in abstracts using AI, and reviewed the pathophysiology, clinical background, radiological features, treatments, and genetic peculiarity of moyamoya disease.

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

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

Encephaloduroarteriosynangiosis (EDAS) treatment of moyamoya syndrome: evaluation by computed tomography perfusion imaging

OBJECTIVE

To explore the value of computed tomography perfusion (CTP) imaging for evaluating the efficacy of encephaloduroarteriosynangiosis (EDAS) treatment of moyamoya syndrome (MMS).

METHODS

Forty-three patients with MMS (48 hemispheres) who received EDAS treatment were examined using CTP and DSA before and after surgery. CTP of the ipsilateral cortex, contralateral mirror area, and pons region were measured, and the relative cerebral blood flow (rCBF) and volume (rCBV), mean transit time (rMTT), and time-to-peak (rTTP) were calculated. Based on postoperative DSA, 48 hemispheres were apportioned to two groups based on rich (grades 2, 3) or poor (grades 0, 1) collateral vessel formation, and the pre- and post-operative differences in perfusion changes were compared. The association between clinical outcome, CTP, and the degree of DSA collateral vessels was explored.

RESULTS

rCBF and rMTT significantly improved in both the poor and rich collateral vessel formation groups (n = 21 and 27, respectively), while rTTP significantly improved only in the latter. Postoperative CTP improved in the rich and the grade 1 collateral vessel groups (p < 0.01). The clinical improvement was consistent with the improvement of CTP (p = 0.07), but less consistent with the degree of collateral angiogenesis (p = 0.003).

CONCLUSION

CTP can quantitatively evaluate the improvement of brain tissue perfusion in the operated area after EDAS. Brain tissue perfusion in operated areas improved regardless of postoperative rich or poor collateral vessel formation observed via DSA. A significant improvement in rTTP in the operated area may indicate the formation of abundant collateral vessels.

KEY POINTS

• CTP showed that brain tissue perfusion in the operated area after EDAS improved regardless of rich or poor collateral vessel formation observed via DSA. • Significant improvement of rTTP in the operated area may indicate the formation of abundant collateral vessels.

Delayed Anastomotic Occlusion after Direct Revascularization in Adult Hemorrhagic Moyamoya Disease

Delayed anastomotic occlusion occurred in a considerable proportion of hemorrhagic moyamoya disease (MMD) patients undergoing direct revascularization. This study aimed to investigate the predictors and outcomes of delayed anastomotic occlusion in adult hemorrhagic MMD. The authors retrospectively reviewed 87 adult hemorrhagic MMD patients. Univariate and multivariate logistic regression analyses were performed. After an average of 9.1 ± 6.9 months of angiographic follow-up, the long-term graft patency rates were 79.8%. The occluded group had significantly worse angiogenesis than the non-occluded group (p < 0.001). However, the improvement of dilated anterior choroidal artery–posterior communicating artery was similar (p = 0.090). After an average of 4.0 ± 2.5 years of clinical follow-up, the neurological statues and postoperative annualized rupture risk were similar between the occluded and non-occluded groups (p = 0.750; p = 0.679; respectively). In the multivariate logistic regression analysis, collateral circulation Grade III (OR, 4.772; 95% CI, 1.184–19.230; p = 0.028) and preoperative computed tomography perfusion (CTP) Grade I–II (OR, 4.129; 95% CI, 1.294–13.175; p = 0.017) were independent predictors of delayed anastomotic occlusion. Delayed anastomotic occlusion in adult hemorrhagic MMD might be a benign phenomenon. Good collateral circulation (Grade III) and compensable preoperative intracranial perfusion (CTP Grade I–II) are independent predictors for this phenomenon. Moreover, the delayed anastomotic occlusion has no significant correlations with the long-term angiographic and neurological outcomes, except neoangiogenesis.

Computed tomographic angiography may be used for assessing the dilatation of the anterior choroidal and posterior communicating arteries in patients with moyamoya syndrome

OBJECTIVE

To evaluate the feasibility of CT angiography (CTA) for assessing anterior choroidal artery (AChA) and posterior communicating artery (PComA) dilatation in patients with moyamoya syndrome (MMS).

METHODS

Eighty-eight MMS patients who underwent digital subtraction angiography (DSA) and CTA within 1 month were enrolled. The AChA was graded using both DSA and CTA. Given the features of dual blood supply, DSA was firstly used for grading of the PComA. Then, the calibers of PComA, P1 or P2 segment of the posterior cerebral artery (PCA), were recorded from CTA. Taking DSA as a reference standard, the optimal cutoff values of the PComA/P1 or PComA/P2 were calculated to determine the dilatation of PComA. Both the AChA and PComA were classified as extreme dilatation (ED, grade 2) or non-extreme dilatation (NED, grade 0 or 1).

RESULTS

The AChA was evaluated in 149 affected hemispheres of 88 patients while the PComA was evaluated in 70 affected hemispheres of 49 patients. The sensitivity and specificity of CTA in diagnosing AChA-ED were 92% and 93.5% respectively. Both the PComA/P1 (p < 0.001) and PComA/P2 (p = 0.4) ratios were increased in the PComA-ED group with the former yielding a better detecting performance than the latter (AUC = 0.92 vs 0.85, p = 0.046). When using 0.71 as a cutoff value, the sensitivity and specificity of the PComA/P1 ratio for diagnosis of PComA-ED cases were 91.3% and 83.3% respectively.

CONCLUSIONS

CTA could be used for the AChA classification in MMS patients, while a PComA/P1 ratio greater than 0.71 indicates the existence of PComA-ED.

KEY POINTS

• CTA showed a high sensitivity, specificity, and accuracy in diagnosing AChA-ED in patients with MMS. • PComA/P1 ratio greater than 0.71 on CTA signified an extremely dilated PComA. • CTA could be used to assess the dilatation of AChA and PComA in MMS patients, especially for routine postoperative follow-up.

Hemorrhagic patterns and their risk factors in patients with moyamoya disease

BACKGROUND AND PURPOSE

The aim was to describe the profiles of hemorrhagic patterns of moyamoya disease (MMD) and analyze the risk factors in a large population.

METHODS

A total of 335 conservatively managed MMD patients with hemorrhage in our hospital were included in this cross-sectional study. The correlation between clinical and angiographic characteristics and hemorrhagic patterns (anterior or posterior hemorrhage) was assessed in the hemorrhagic hemisphere by univariate and multivariate logistic regression models. In addition, stratified analysis was performed.

RESULTS

The 335 hemorrhagic hemispheres (patients) comprised 179 (53.4%) anterior and 156 (46.6%) posterior hemorrhages. For all cases, age at onset [odds ratio (OR) 0.98; 95% confidence interval (CI) 0.96-1.00; P = 0.048] and choroidal anastomosis (OR 1.87; 95% CI 1.19-2.94; P = 0.007) were found by multivariate regression analysis to be negatively and positively associated with a significantly increased risk of posterior hemorrhage, respectively. After stratified analysis, hypertension (OR 0.37; 95% CI 0.14-0.97; P = 0.043) was identified by multivariate regression analysis as a risk factor for anterior hemorrhage in patients without dilation of choroidal anastomosis. On the other hand, choroidal anastomosis (OR 2.62; 95% CI 1.02-6.72; P = 0.045) and involvement of the posterior cerebral artery (OR 3.39; 95% CI 1.20-9.63; P = 0.022) were associated with significantly increased risk of posterior hemorrhage in children and young adults (<30 years of age).

CONCLUSIONS

A dynamic change in hemorrhagic patterns in MMD patients with increasing age at onset was observed. Choroidal anastomosis is a predictor of posterior hemorrhage. Hypertension is a risk factor for anterior hemorrhage in patients without extreme dilation of choroidal anastomosis.

Clinical and Radiological Outcomes After Revascularization of Hemorrhagic Moyamoya Disease

Objective: To evaluate clinical and radiological outcomes after revascularization of hemorrhagic moyamoya disease (MMD).

Materials and Methods: We retrospectively collected patients with hemorrhagic MMD who received revascularization from January 2011 to June 2018 at a high-volume stroke center. Rebleeding, ischemic stroke, modified Rankin Scale (mRS) and death after revascularization were used to evaluate long-term clinical outcome. Poor neurological outcome was defined as a mRS>2. The changes of original and revascularization collaterals were used to evaluate radiological outcome. The clinical and radiological outcomes between patients with different surgical revascularization were compared.

Results: A total of 312 patients (319 hemispheres) were recruited, including 133 hemispheres (41.7%) with indirect revascularization and 186 hemispheres (58.3%) with direct revascularization. In 308 hemispheres with clinical follow-up data, Postoperative rebleeding, ischemic stroke, poor neurological outcome and death occurred in 13.0% (40/308), 2.6% (8/308), 12.0% (37/308), and 6.2% (19/308) of the hemispheres, respectively. The rates of postoperative rebleeding (8.5 vs. 19.1%, P = 0.006) and poor neurological outcome (8.5 vs. 16.8%, P = 0.026) were lower in hemispheres with direct revascularization than those with indirect revascularization. However, there was no statistically significant difference in the rates of postoperative ischemic stroke (1.1 vs. 4.6%, P = 0.129) and death (4.5 vs. 8.4%, P = 0.162) between the two groups. Multivariate logistic regression analysis indicated that the risk of postoperative rebleeding was higher in those with untreated aneurysms, repetitive bleeding episodes, normal perfusion status, and indirect revascularization (P < 0.05). In 78 hemispheres with radiological follow-up data, the regression of moyamoya vessels, anterior choroidal artery (AchA), posterior communicating artery (PcomA) and aneurysms were present in 44.9, 47.4, 25.6, and 11.5% of the hemispheres, respectively. The regression of original collaterals and establishment of revascularization collaterals were more significant in hemispheres with direct revascularization than those with indirect revascularization (P < 0.05).

Conclusion: Direct revascularization may be superior to indirect revascularization for prevention of rebleeding and poor neurological outcome in adults with hemorrhagic MMD. The risk of postoperative rebleeding was higher in those with untreated aneurysms, repetitive bleeding episodes, normal perfusion status, and indirect revascularization. The regression of original collaterals and establishment of revascularization collaterals after revascularization were more significant in hemispheres with direct revascularization than those with indirect revascularization.

Cerebral Hemodynamic Changes After Revascularization in Patients With Hemorrhagic Moyamoya Disease

Objective: To explore the cerebral hemodynamic changes after revascularization in patients with hemorrhagic moyamoya disease (MMD).

Materials and Methods: We retrospectively included 57 hemorrhagic MMD patients in a high-volume stroke center from January 2016 to December 2018. All subjects were evaluated with whole-brain CT perfusion (CTP) before and after surgical revascularization. Absolute and relative CTP values in the regions of cortical middle cerebral artery territory (CMT) and deep brain area (DBA) of hemorrhagic hemispheres were measured. Differences between pre- and post-operative CTP values were assessed comprehensively. The patients were categorized into subgroups based on revascularization subtypes and postoperative CTP intervals.

Results: The relative cerebral blood volume (rCBV) in DBA and CMT significantly reduced in postoperative CTP (P < 0.05). The median and interquartile range of the proportion of rCBV decrease (rCBVc%) were 7.2% (2.3–13.2%). The rCBV reduction retained statistical significant in patients who received subtypes of revascularization, and in patients with variable intervals of follow-up (P < 0.05). There was no significant difference of rCBVc% between patients who received different revascularization and among patients with different postoperative CTP intervals (P > 0.05). The relative mean transit time (rMTT) and relative time to peak (rTTP) also showed downward trends, but without retainable statistical significance in stratified analysis. There was no significant change in relative cerebral blood flow (rCBF) (P > 0.05).

Conclusion: In patients with hemorrhagic MMD, the CBV appeared to decrease and be relatively stable in the chronic phase after revascularization, with varying degrees of MTT and TTP shortening. However, there was no significant change in CBF.

Postoperative collateral formation after indirect bypass for hemorrhagic moyamoya disease

Background

The research on postoperative collateral formation for hemorrhagic moyamoya disease (MMD) evaluated by using digital subtraction angiography (DSA) is limited. Our study objective was to investigate the postoperative collateral formation after indirect bypass for hemorrhagic MMD.

Methods

All consecutive inpatients with hemorrhagic MMD who received indirect bypass at Beijing Tiantan Hospital, Capital Medical University from January 2010 through December 2018 were screened. The site of the hemorrhage was classified as either anterior or posterior. Postoperative collateral formation was evaluated on lateral views using the Matsushima scale. Univariate and multivariate logistic regression analyses were carried out to determine the factors influencing postoperative collateral formation.

Results

Six-four patients (64 hemispheres) were included in this study. After a median 8.5 months DSA follow-up, 14 (21.9%) hemispheres had grade A collateral circulation, 13 (20.3%) had grade B, and 37 (57.8%) had grade C. Twenty-seven (42.2%) hemispheres had good postoperative collateral formation and 37 (57.8%) had poor postoperative collateral formation. The univariate logistic regression analyses showed that age at operation (OR, 0.954; 95% CI, 0.908–1.003; p = 0.066), hemorrhagic site (OR, 4.694; 95% CI, 1.582–13.923; p = 0.005), and PCA involvement (OR, 3.474; 95% CI, 0.922–13.086; p = 0.066) may effect postoperative collateral formation. The multivariate logistic regression analyses showed that only anterior hemorrhage (OR, 5.222; 95% CI, 1.605–16.987; p = 0.006) was significantly related to good postoperative collateral formation.

Conclusion

Anterior hemorrhage was significantly related to good postoperative collateral formation after indirect bypass.

Moyamoya angiopathy: long-term follow-up study in a Finnish population

BACKGROUND AND PURPOSE

Moyamoya angiopathy (MMA) is a chronic cerebrovascular disorder predominantly starting in childhood or early adulthood and thus affects the whole lifetime. Little is known on MMAs long-term outcomes in European patients. We report long-term follow-up data on Finnish MMA patients.

METHODS

We included patients from our Helsinki University Hospital MMA database and arranged long-term follow-up visits for all the patients. This follow-up included a review of the medical records accumulated in due time, detailed neurological and neuropsychological evaluation, and outcome measures modified Rankin Scale (mRS) and Barthel Index (BI).

RESULTS

There were 61 MMA patients with a mean follow-up period of 9.5 years (SD 6.7 years; range 1.3-35.4 years; 581 patient-years). Only two patients had died and two-thirds (n = 40, 65.6%) had no new events during the follow-up period. Eight patients (13.1%) had an ischemic and five patients (8.2%) a hemorrhagic stroke during the follow-up. There were no differences between operated (n = 26) and conservatively (n = 35) treated groups regarding recurrent events or the outcome measured with mRS or BI. Finnish MMA patients reported significantly poorer physical and psychological health aspects of QOL when compared to the general Finnish population. Symptoms of low mood were found in 27 (56%) patients.

CONCLUSIONS

Finnish MMA patients have a benign and stable course with a ~3.5 % annual stroke risk. We found no differences in the clinical outcomes between the operated and conservative groups, however, the psychosocial well-being requires more attention in MMA patients.