Posterior cerebral territory ischemia in pediatric moyamoya: Surgical techniques and long-term clinical and radiographic outcomes.

PURPOSE: To describe a surgical technique for posterior cerebral revascularization in pediatric patients with moyamoya arteriopathy. Here, we describe the clinical characteristics, surgical indications, operative techniques, and clinical and radiographic outcomes in a series of pediatric patients with moyamoya disease affecting the posterior cerebral artery (PCA) territory. METHODS: A retrospective single-center series of all pediatric patients with moyamoya disease who presented to our institute between July 2009 through August 2019 were reviewed. The clinical characteristics, surgical indications, operative techniques, and long-term clinical and radiographic outcomes of pediatric moyamoya patients with PCA territory ischemia were collected and analyzed. RESULTS: A total of 10 PCA revascularization procedures were performed in 9 patients, 5 female, ages 1 to 11.1 years (average 5.2 years). Complications included 1 stroke, with no infections, hemorrhages, seizures, or deaths. One patient had less than 1 year of radiographic and clinical follow-up. In 8 of 9 patients with at least 1 year of radiographic follow-up, there was engraftment of surgical vessels present in all cases. No new strokes were identified on long-term follow-up despite the radiographic progression of the disease. In the 8 cases available for analysis, the average follow-up was 50.8 months with a range of 12 to 117 months. CONCLUSIONS: PCA territory ischemia in patients with progressive moyamoya disease can be surgically treated with indirect revascularization. Here, we describe our experience with PCA revascularization procedures for moyamoya disease, including pial pericranial dural (PiPeD) revascularization and pial synangiosis utilizing the occipital artery. These surgical options may be useful for decreasing the risk of stroke in pediatric moyamoya patients with severe posterior circulation disease.

Technical evolution of pediatric neurosurgery: moyamoya disease.

Moyamoya disease (MMD) is a rare steno-occlusive disease of the bilateral internal carotid arteries that predominantly occurs in East Asia. Since the first description of the MMD by Suzuki and Takaku in 1969, significant advances have been made in both basic and clinical understanding of the disease. The incidence and prevalence of pediatric MMD have increased, potentially due to improved detection rates. The advancement of neuroimaging techniques has enabled MRI-based diagnostics and detailed visualization of the vessel wall. Various methods of surgical treatments are successful in pediatric MMD patients, and recent studies emphasize the importance of reducing postoperative complications since the goal of MMD surgery is to prevent future cerebral infarction and hemorrhage. Long-term outcomes following appropriate surgical treatment in pediatric MMD patients have shown promising results, including favorable outcomes in very young patients. Further studies with a large patient cohort are needed to establish individualized risk group stratification for determining the optimal timing of surgical treatment and to conduct multidisciplinary outcome assessments.

The neurosurgical management of Severe Hemophilia A and Moyamoya (SHAM): challenges, strategies, and literature review.

INTRODUCTION: Severe Hemophilia A and Moyamoya arteriopathy (SHAM syndrome) is a rare genetic disorder caused by deletion of portions of the cytogenic band Xq28. A case of SHAM syndrome requiring bilateral cerebral revascularization is described with an emphasis on perioperative management. CASE REPORT: A 5-year-old boy with severe hemophilia A complicated by factor VIII inhibition presented with right-sided weakness. Imaging revealed multiple strokes and vascular changes consistent with Moyamoya disease. The patient underwent two-staged indirect cerebral bypass revascularizations, first on the left side and several months later on the right. Perioperative management required balancing the administration of agents to prevent coagulopathy and perioperative hemorrhage while mitigating the risk of thromboembolic events associated with bypass surgery. Despite a multidisciplinary effort by the neurosurgery, hematology, critical care, and anesthesiology teams, the post-operative course after both surgeries was complicated by stroke. Fortunately, the patient recovered rapidly to his preoperative functional baseline. CONCLUSION: We describe a rare case of SHAM syndrome in a pediatric patient who required bilateral revascularizations and discuss strategies for managing the perioperative risk of hemorrhage and stroke. We also review existing literature on SHAM syndrome.

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.

Early and noninvasive evaluation using superficial temporal artery duplex ultrasonography after indirect bypass for adult ischemic moyamoya disease.

BACKGROUND: The validity of indirect bypass for adult patients with moyamoya disease is still debatable. Some patients are poor responders to indirect bypass, and additive intervention is occasionally required in these cases. Therefore, it is necessary to evaluate the development of collateral circulation as early as possible postoperatively. METHODS: Fifteen adult patients (>17 years old) with moyamoya disease (22 affected sides) who underwent encephalo-duro-arterio-synangiosis (EDAS) at Fukuoka University Hospital from April 2008 to August 2014 were included. All patients had ischemic symptoms of at least one hemisphere. Superficial temporal artery duplex ultrasonography (STDU) was performed before and 3, 6, and 12 months postoperatively. Digital subtraction angiography was performed 1 year after the operation to evaluate the development of collateral circulation. Hemispheres exhibiting collateral formation of more than one-third of the MCA distribution were defined as good responders, and those with less than one-third were defined as poor responders. RESULTS: EDAS induced the formation of well-developed collaterals in 17 of 22 affected sides (77.3%) of adult patients with ischemic moyamoya disease. Regardless of the degree of collateral formation, the ischemic event subsided eventually with time in all patients. In good responders, the pulsatility index obtained by STDU showed a drastic decrease 3 months after the operation, while it did not change significantly in poor responders. Absence of this decrease in the pulsatility index along with no change in the flow velocity reliably indicated poor responders. CONCLUSIONS: Neovascularization after EDAS can be evaluated noninvasively in early phase using STDU.

Hemodynamic study with duplex ultrasonography on combined (direct/indirect) revascularization in adult moyamoya disease.

BACKGROUND: To evaluate the hemodynamic changes by duplex ultrasonography in adult moyamoya disease (MMD) patients who underwent combined direct and indirect revascularization surgery. METHODS: Seventeen adult patients underwent direct and indirect revascularization surgery in our hospital. Hemodynamic parameters, peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistance index (RI), were determined by color Doppler at the baseline, 2 weeks, and 6 months after bypass. RESULTS: Both the PSV and EDV of direct bypass were lower at 6 months after surgery compared with those at 2 weeks postoperatively. The EDV of indirect revascularization surgery of the maxillary artery (MA) at 6 months after surgery was higher and the RI of the MA lower compared with the baseline levels. Decreased PSV and EDV in the bypass vessel did not significantly correlate with increased EDV or decreased RI of the MA. CONCLUSIONS: Duplex ultrasonography is a reliable, noninvasive tool to assess hemodynamic changes and evaluate the therapeutic performance of combined bypass surgery in adult MMD.

Superficial Temporal Artery Size Changes After Encephaloduroarteriosynangiosis (EDAS) for the Treatment of Moyamoya Disease.

BACKGROUND AND OBJECTIVES: Surgery is the mainstay of stroke prevention in patients with symptomatic Moyamoya disease. We present the results of a single-center retrospective study of indirect revascularization surgery for adult moyamoya disease, emphasizing angiographic outcomes, including dilation of the superficial temporal artery and formation of new collaterals. METHODS: A prospectively maintained database of procedures performed for Moyamoya disease was reviewed. Adult patients treated with indirect revascularization and with long-term angiographic follow-up were included. Pre-operative 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 (EDAS) for treatment. A follow-up angiogram was performed at a median of 13.8 months postoperatively, showing 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. CONCLUSION: A significant increase in STA diameter on follow-up angiography after EDAS 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.

Indirect Bypass With Pericranial Transposition for Moyamoya Syndrome in an Infant.

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

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.

Revascularization Surgery for Moyamoya Vasculopathy: An Australian Experience.

BACKGROUND: Moyamoya vasculopathy is a rare steno-occlusive cerebrovascular disorder presenting with ischemia or hemorrhage. There are racial and geographic differences in presentation and outcome. There is little information regarding moyamoya in Australia. METHODS: Moyamoya patients undergoing surgery from 2001 to 2022 were studied retrospectively. The outcomes of revascularization surgery in adult and pediatric patients, with ischemic and hemorrhagic disease were analyzed, including functional outcomes, postoperative complications, bypass patency, and long-term rates of ischemic and hemorrhagic events. RESULTS: A total of 68 patients with 122 revascularized hemispheres and 8 posterior circulation revascularizations were included in this study. Eighteen patients were of Asian descent and 46 were of Caucasian origin. Presentation was with ischemia in 124 hemispheres and hemorrhage in six hemispheres. There were 92 direct, 34 indirect, and 4 combined revascularization surgeries performed. Early postoperative complications occurred in 3.1% (n = 4) of operations and delayed complications (infection, subdural hematoma) occurred after 4.6% (n = 6) of operations. Mean follow-up was 6.5 years (3-252 months). There was 100% patency of direct grafts at last follow-up. There were no hemorrhagic events following surgery and 1 new ischemic event 2 years after surgery. There was significant improvement in physical health functional outcomes at most recent follow-up (P < 0.05); mental health outcomes were not different between preoperative and postoperative assessments. CONCLUSIONS: The majority of Australian moyamoya patients are Caucasian and the most common clinical presentation is ischemia. Revascularization surgery had excellent outcomes with very low rates of ischemia and hemorrhage, comparing favorably to the natural history of moyamoya vasculopathy.

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.

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.

Salvage Superficial Temporal Artery to Middle Cerebral Artery Direct Bypass Using an Interposition Graft for Failed Encephaloduroarteriosynangiosis in Moyamoya Disease.

BACKGROUND: Moyamoya disease may present with either hemorrhagic or ischemic strokes. Surgical bypass has previously demonstrated superiority when compared to natural history and medical treatment alone. The best bypass option (direct vs. indirect), however, remains controversial in regard to adult ischemic symptomatic moyamoya disease. Multiple studies have demonstrated clinical as well as angiographic effectiveness of direct bypass in adult hemorrhagic moyamoya disease. In particular, there are limited data regarding strategies in the setting of failed indirect bypass with recurrent hemorrhagic strokes. Here, we describe a salvage procedure. METHODS: We describe a case of a 52-year-old man who presented with hemorrhagic moyamoya disease and failed previous bilateral encephaloduroarteriosynangiosis (EDAS) procedures at an outside institution. On a 3-year follow-up diagnostic cerebral angiogram, no synangiosis was noted on the right side and only minimal synangiosis was present on the left. The left hemisphere was significant for a left parietal hypoperfusion state. We performed a salvage left proximal superficial temporal artery to distal parietal M4 middle cerebral artery bypass using the descending branch of the lateral circumflex artery as an interposition graft with preservation of the existing EDAS sites. RESULTS: The patient underwent the procedure successfully and recovered well with resolution of headaches and no further strokes or hemorrhages on the 1-year follow-up magnetic resonance imaging of the brain. CONCLUSIONS: This case presents the use of a salvage direct bypass technique for recurrent symptomatic hemorrhagic moyamoya disease after failed EDAS. The strategy, approach, and technical nuances of this unique case have implications for revascularization options.

A meta-analysis of comparisons of various surgical treatments for moyamoya diseases.

PURPOSE: Ischemia is one of the most familiar complications in the different procedures for moyamoya disease (MMD), but the optimal surgical approaches for MMD remain unknown. We aimed to evaluate the efficiency of various surgical treatments. METHODS: A literature search word was performed through four databases such as Cochrane Library, Web of Science, PubMed, and EMBASE for the literature published until May 2021. The I2 statistic was used to assess heterogeneity. A random/fixed-effects model was used to pool. RESULTS: There are a total of 18 studies including three surgical treatments such as including indirect, direct, and combined bypass in this study. The result revealed that indirect bypass was related to a higher incidence of recurrence stroke compared to the direct and combined bypass treatment (p = .001). Furthermore, the cases undergoing direct bypass were associated with a better angiographic change than the indirect bypass (OR = 3.254, p = .013). CONCLUSION: This meta-analysis demonstrated a positive effect of using the direct and combined bypass to treat MMD compared to indirect bypass due to their lower rates of recurrence stroke.

Postoperative neovascularization, cerebral hemodynamics, and clinical prognosis between combined and indirect bypass revascularization procedures in hemorrhagic moyamoya disease.

OBJECTIVE: We evaluated what few studies emphasized the postoperative collateral formation and cerebral hemodynamics of hemorrhagic moyamoya disease (MMD). METHODS: Hemorrhagic MMD patients treated surgically were retrospectively collected and dichotomized into combined bypass (CB) and indirect bypass (IB) groups. CB used superficial temporal artery-to-middle cerebral artery anastomosis combined with encephaloduroarteriomyosynangiosis (STA-MCA+EDAMS), and IB used encephaloduroarteriomyosynangiosis (EDAMS) for revascularization. Postoperative complications and clinical prognosis, as well as pre- and post-operative Modified Rankin Scale (mRS), collateral circulation status, and cerebral hemodynamics were observed and compared between the CB and IB groups. RESULTS: A total of 37 patients with hemorrhagic MMD were identified. Of the 68 cerebral hemispheres, 47(69.1%) were combined revascularization, and the rest were indirect. During an average follow-up of 16.5 ± 8.7 months, the recurrent stroke events were significantly lower, as well as having a postoperative mRS scores≤ 2. A satisfactory postoperative collateral formation, and an improved dilation or extension of the anterior choroidal/posterior communication artery (AchA/PcoA) were significantly higher in the CB group than in the IB group (all P < .05). Compared with preoperative cerebral hemodynamics, relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), mean transit time (MTT), and relative time to peak (rTTP) in the CB group; rCBF, rCBV, and MTT in the IB group were significantly improved (all P < .001). The CB group's postoperative rCBF was significantly improved compared with the IB group (P < .001). CONCLUSIONS: STA-MCA bypass combined with EDAMS can obtain better postoperative collateral formation, cerebral hemodynamics, and clinical prognosis than EDAMS alone.

Use of a panel of four microRNAs in CSF as a predicted biomarker for postoperative neoangiogenesis in moyamoya disease.

INTRODUCTION AND AIMS: At present, the treatment for moyamoya disease (MMD) primarily consists of combined direct and indirect bypass surgery. Nevertheless, more than half of indirect bypass surgeries fail to develop good collaterals from the dura and temporal muscle. This study aimed to investigate whether microRNAs (miRNAs) in cerebrospinal fluid (CSF) could serve as biomarkers for the prediction of postoperative collateral formation. METHODS: Moyamoya disease patients with indirect bypass surgery were divided into angiogenesis and non-angiogenesis groups, CSF was obtained, and miRNA sequencing was performed using the CSF. Candidate miRNAs were filtered and subsequently verified through qRT-PCR. The diagnostic utility of these differential miRNAs was investigated by using receiver operating characteristic (ROC) curve analysis. Finally, the potential biological processes and signaling pathways associated with candidate miRNAs were analyzed using R software. RESULTS: The expression levels of four miRNAs (miR-92a-3p, miR-486-3p, miR-25-3p, and miR-155-5p) were significantly increased in the angiogenesis group. By combining these four miRNAs (area under the curve [AUC] =0.970), we established an accurate predictive model of collateral circulation after indirect bypass surgery in MMD patients. GO and KEGG analyses demonstrated a high correlation with biological processes and signaling pathways related to angiogenesis. CONCLUSION: The 4-miRNA signature is a good model to predict angiogenesis after indirect bypass surgery and help the surgeon to select a appreciate bypass strategy.

Association between bilateral postoperative neoangiogenesis in patients with moyamoya disease.

OBJECTIVE: The research on neoangiogenesis after indirect bypass for moyamoya disease (MMD) evaluated by using digital subtraction angiography (DSA) is limited. Our study objective was to investigate association of bilateral postoperative neoangiogenesis in patients with MMD. PATIENTS AND METHODS: All consecutive inpatients with MMD who received bilateral indirect bypass at Beijing Tiantan Hospital, Capital Medical University from January 2011 through December 2017 were screened. Bilateral neoangiogenesis was evaluated on lateral views and anteroposterior views by using DSA. RESULTS: Twenty-two patients (44 hemispheres) were included in this study. After a median 7.5 months DSA follow-up, on lateral views, 9 (40.9 %) hemispheres had grade A, 8 (36.4 %) hemispheres had grade B, and 5 (22.7 %) hemispheres had grade C after bypass on one side; 11 (50.0 %) hemispheres had grade A, 7 (31.8 %) hemispheres had grade B, and 4 (18.2 %) hemispheres had grade C after bypass on contralateral side. On anteroposterior views of ECA, 2 (9.1 %) hemispheres had level 0, 3 (13.6 %) had level 1, 6 (27.3 %) had level 2, and 11 (50.0 %) had level 3 after bypass on one side; 2 (9.1 %) hemispheres had level 0, 2 (9.1 %) had level 1, 6 (27.3 %) had level 2, and 12 (54.6 %) had level 3 after bypass on contralateral side. There was strong association between bilateral postoperative neoangiogenesis on lateral views (rs = 0.770; p = 0.000) and the anteroposterior views (rs = 0.548; p = 0.008). CONCLUSIONS: There was strong association between bilateral postoperative neoangiogenesis. Postoperative neoangiogenesis on one side might predict the postoperative neoangiogenesis on the other side.

Simultaneous Left Superficial Temporal Artery-Middle Cerebral Artery Bypass and Encephalodurovenosynangiosis for Progressive Atherosclerosis of the Left Internal Carotid Artery Communicating Segment.

Combined direct and indirect bypass have been described in the literature as a complementary technique.1 Direct superficial temporal artery-to-middle cerebral artery bypass is a cornerstone for adult moyamoya disease and syndrome as it provides immediate vascular supply.2 However, the donor vessel caliber and thus blood flow are subject to decrease over time, mainly due to new collateral formation.3 Encephaloduroarteriosynangiosis provides long-term blood supply and new collateral formation. We describe a case of progressive left internal carotid artery communicating segment atherosclerosis in a 34-year-old woman. An indirect bypass using the superficial temporal vein was chosen on the basis of absence of the left parietal branch of the superficial temporal artery.

Time Course of Neoangiogenesis After Indirect Bypass Surgery for Moyamoya Disease : Comparison of Short-term and Long-term Follow-up Angiography.

OBJECTIVE: Indirect bypass surgery, which induces spontaneous neoangiogenesis in ischemic brain tissue and improves cerebral blood flow, is an effective treatment for moyamoya disease (MMD). The time course of neoangiogenesis development has not yet been investigated. This study aimed to determine the critical period of neovascularization after indirect bypass in MMD patients. METHODS: Patients with MMD who underwent indirect bypass surgery at Peking University International Hospital between January 2015 and October 2017 were retrospectively reviewed. Surgically treated hemispheres with short-term (3-6 months) and long-term (1 year) follow-up digital subtraction angiography (DSA) were included. The effects of revascularization were evaluated on lateral and anteroposterior views using angiography and compared between two follow-ups of the same hemisphere. RESULTS: This study included 25 hemispheres from 24 MMD patients (mean age: 22.48 ± 14.83 years), among whom 13 were pediatric patients and 12 were adults. Qualitative measurements including the Matsushima scale and coverage of neoangiogenesis on anteroposterior views were not significantly different between the short term and long term (P = 0.083 and P = 0.157, respectively). Quantitative measurements including the greatest width and height of the area covered by neovascularization on lateral views of DSA and the greatest depth of neovascularization penetration on anteroposterior views (P = 0.488, 0.298 and 0.527, respectively) were also not significantly different. The mean count of newly formed veins was more at long-term than short-term follow-up (5.5 ± 2.5 vs. 5.1 ± 2.4, P = 0.005). Subgroup analysis of pediatric patients and adults yielded the same results as in the whole series. CONCLUSION: After indirect bypass surgery, the major time window of arterial neoangiogenesis development was within 6 months after surgery. The general effect of revascularization was very similar in the short and long term; therefore, a follow-up angiography scheduled at 6 months after surgery is recommended. Growth of veins might continue after 6 months.

Occipital to Angular Artery Bypass for Post-irradiation Ischemia: 3-Dimensional Operative Video.

The authors present a 3D surgical video of a direct occipital to angular artery bypass for cerebral revascularization in the setting of Post-irradiation middle cerebral artery stenosis and symptomatic hypoperfusion. The case refers to a 50-yr-old woman with a history of an unresectable residual skull base meningioma, previously approached through a left frontotemporal craniotomy, and treated with radiation 5 yr prior to presentation. She now presented with right-sided limb shaking transient ischemic attacks and aphasia, along with evidence of left middle cerebral artery territory ischemia. Her symptoms were progressive, despite extensive external carotid collateral blood supply through the prior craniotomy. The video analyzes the surgical steps of the procedure, emphasizing multiple surgical pearls. After positioning, an incision is designed to expose the full course of the occipital artery. After dissection of the donor vessel, a craniotomy is performed to expose the distal sylvian fissure. The donor and recipient vessels are prepared, and the anastomosis is performed with interrupted sutures given the sub-millimeter diameter of the recipient vessel (suture used: 10-0 Ethilon BV75-3 Taper, Ethicon, Johnson & Johnson). Every step of the closure is modified to avoid any constriction of the donor vessel. The patient tolerated the procedure well, and multiple modalities, both intra- and post operatively confirmed patency of, and robust flow within the bypass. No identifying patient information is included. However, the patient's consent was obtained for this publication.