Risk Factors for Neurologic Deterioration After Revascularization Surgery in Patients with Moyamoya Disease

Inhalational Anesthesia Reduced Transient Neurological Events After Revascularization Surgery for Moyamoya Disease

BACKGROUND AND OBJECTIVES

The choice between inhalational and total intravenous anesthesia (TIVA) in revascularization surgery for Moyamoya disease (MMD) remains a topic of debate. Anesthesia methods have changed with the advent of new anesthetics. This study investigated whether modern anesthesia methods affected the development of neurological symptoms after revascularization surgery for MMD.

METHODS

This single-center retrospective study included 63 adult patients (82 hemispheres) with MMD treated with direct and indirect bypass surgeries at our hospital between 2013 and 2022. Patients were divided into inhalational anesthesia (IA) and TIVA groups based on the anesthesia maintenance method. Baseline patient characteristics; postoperative neurological symptoms, including hyperperfusion syndrome, cerebral infarction, and transient neurological events (TNEs); and cortical hyperintensity belt (CHB) sign scores (5-point scale from 0 to 4) on postoperative magnetic resonance imaging were compared between the two groups. The operation methods, anesthetics, and intraoperative hemodynamic and ventilatory parameters were compared between patients with and without TNEs.

RESULTS

The IA and TIVA groups comprised 39 and 43 hemispheres, respectively. The frequency of postoperative hyperperfusion syndrome and cerebral infarction did not differ between the groups, but the number of TNEs in the IA group (5/39; 13%) was significantly lower than that in the TIVA group (16/43; 37%). Multivariate logistic regression analysis revealed that TNEs were associated with TIVA (odds ratio, 3.91; 95% CI, 1.24-12.35; P = .02). The median [IQR] postoperative CHB sign score in the IA group (2 [1-3]) was significantly lower than that in the TIVA group (4 [3-4]).

CONCLUSION

The IA group had fewer postoperative TNEs and lower CHB sign scores than the TIVA group. Although further studies are needed, this study provides insights into the prevention of TNEs with IA and reconsideration of the optimal anesthesia for MMD.

Risk factors of postoperative cerebral hyperperfusion syndrome and its relationship with clinical prognosis in adult patients with moyamoya disease

BACKGROUND

To investigate the incidence, risk factors, and clinical prognosis of cerebral hyperperfusion syndrome (CHS) after superficial temporal artery-middle cerebral artery anastomosis combined with encephalo-duro-arterio-synangiosis (STA-MCA/EDAS) in adult patients with moyamoya disease (MMD).

METHODS

The clinical data of 160 adult patients with MMD treated by STA-MCA/EDAS from January 2016 to January 2017 were retrospectively analyzed. According to CHS diagnosis, MMD patients were divided into CHS and non-CHS group. Univariate and multivariate analysis of risk factors and Kaplan-Meier curve of stroke-free survival for CHS were performed.

RESULTS

A total of 12 patients (7.5%) developed postoperative CHS, of which 4 patients (2.5%) presented with cerebral hemorrhage. Univariate and multivariate analysis showed moyamoya vessel on the surgical hemisphere (OR = 3.04, 95% CI = 1.02-9.03, P = 0.046) and left operated hemisphere (OR = 5.16, 95% CI = 1.09-21.34, P = 0.041) were independent risk factors for CHS. The other variables, such as age, gender, presentation, hypertension, diabetes, smoking, mean mRS score on admission, modified Suzuki stage and pre-infarction stage on surgical hemisphere, and bypass patency, had no association with postoperative CHS (P > 0.05). At final follow-up with average 38 months, there were 18 out of 133 patients (13.5%, 4.91% per person year) presented with newly developed complications. There was no significant difference between newly developed complications, mean mRS scores, and Kaplan-Meier curve of stroke-free survival in patients with and without CHS (P > 0.05).

CONCLUSION

The concentration of moyamoya vessels and left operated hemisphere was independent risk factors for CHS, which could not affect the clinical prognosis if treated timely and properly. The current study offers a new perspective of moyamoya vessels and supporting data for choosing MMD candidates on cerebral revascularization.

Transient ischemic attack after indirect revascularization surgery for pediatric patients with moyamoya disease: A retrospective study of intraoperative blood pressure

BACKGROUND

This study aimed to investigate the association between intraoperative blood pressure and postoperative transient ischemic attacks (TIAs) in pediatric patients with moyamoya disease after indirect revascularization surgery.

METHODS

We retrospectively reviewed the medical records of patients with moyamoya disease younger than 15 years who underwent indirect revascularizations under general anesthesia from 2013 to 2019. Perioperative clinical factors and intraoperative blood pressure data were collected and analyzed. Univariate and multivariable mixed-effect logistic regressions were used to identify predictors of postoperative TIA and symptom progression.

RESULTS

Among 444 hemispheres in 296 pediatric patients, 70 cases (16%) experienced postoperative TIAs within 2 weeks after surgery, and 34 cases (7.7%) developed postoperative symptom progression. Baseline mean blood pressure (MBP) (adjusted odds ratio, 1.261; 95% confidence interval, 1.037-1.528; P < 0.001), Average mean arterial pressure (MAP) (adjusted odds ratio, 1.137; 95% confidence interval, 1.052-1.228; P = 0.006), and Ipsilateral magnetic resonance angiography (MRA) score (adjusted odds ratio, 1.464; 95% confidence interval, 0.886-2.419; P = 0.012) were statistically significant risk factors for postoperative TIA. Average real variability of MAP (ARV-MAP), which were measures of intraoperative MAP variability (adjusted odds ratio, 4.731; 95% confidence interval, 1.419-15.257; P = 0.003) and maximum MAP declination (MaxD-MAP) (adjusted odds ratio, 1.271; 95% confidence interval, 1.013-1.520; P = 0.010) were statistically significant risk factors for postoperative symptom progression.

CONCLUSION

Higher pre-induction baseline blood pressure and ipsilateral MRA score were independent risk factors predicting postoperative TIA in pediatric patients with moyamoya disease after indirect revascularization. The high variability and drastic decline in intraoperative MAP showed predictive value in postoperative symptom progression.

Ten-year experience with laparoscopic pedicled omental flap for cerebral revascularization in patients with Moyamoya disease

BACKGROUND

The omental flap has numerous extraperitoneal applications in reconstruction and revascularization given its favorable immunologic and angiogenic properties. In patients with Moyamoya disease, cerebral revascularization using a pedicled omental flap has proven to be a viable option following direct revascularization procedures. Historically, harvesting omentum involved laparotomy with the associated risk of complications; herein we describe outcomes from a 10-year experience of laparoscopic harvesting of pedicled omental flap for cerebral revascularization in Moyamoya patients.

METHODS

A retrospective chart review was performed of all patients with Moyamoya disease who underwent laparoscopic omental cerebral transposition between 2011 and 2021. Intraoperative and postoperative complications, length of stay (LOS), and outcomes at follow-up were analyzed.

RESULTS

Twenty-one patients underwent the procedure during the study period. Three intraoperative complications occurred (one segmental transverse colectomy for mesenteric injury, one converted to omental free flap, and one requiring micro anastomosis). Average overall LOS was 6 ± 6 days, with 3 ± 3.5 days in the ICU (mean±SD). Following discharge, complications included epigastric incisional hernia at the graft fascial exit site, recurrent neck pain at subcutaneous tunneling site, and partial scalp necrosis. One patient required subsequent direct bypass seven months after the initial procedure owing to the progression of the disease. All other patients had partial or complete resolution of symptoms.

CONCLUSION

Our retrospective observational study indicates that laparoscopic pedicled omental flap mobilization and transposition is a safe and effective method of indirect cerebral revascularization in patients with Moyamoya disease.

LEVEL OF EVIDENCE

N/A.

Endovascular treatment of main trunk aneurysms in the residual anterior circulation in moyamoya disease

BACKGROUND

Main trunk aneurysms in the residual anterior circulation in moyamoya disease (MMD) are uncommon, and in such cases, endovascular treatment (EVT) is a good choice.

MATERIALS AND METHODS

A retrospective study was performed on 35 consecutive patients admitted to our hospital who were diagnosed with MMD and main trunk aneurysms in the residual anterior circulation and were treated with EVT.

RESULT

The 35 patients were aged 38-77 years (mean, 56.1 ± 8.8 years) and included 17 females (48.6%, 17/35). There were 29 cases (82.9%, 29/35) of hemorrhagic onset. In 35 patients, there were 38 main trunk aneurysms in the residual anterior circulation. Thirty-eight aneurysms underwent coiling; among them, coiling with stent assistance was used in the treatment of 6 (15.8%, 6/38) aneurysms. The immediate modified Raymond-Roy classification (MRRC) was grade I for all aneurysms. Among 35 patients, intraoperative bleeding occurred in 2 (5.7%, 2/35) patients. After EVT, immediate hemiplegia occurred in 4 (11.4%, 4/35) patients, and immediate coma occurred in 1 (2.9%, 1/35) patient. At discharge, in 35 patients, the Glasgow Outcome Scale (GOS) was five in 88.6% of them. Of 35 patients, 68.6% had follow-up data, GOS was five in 87.5% patients, and the MRRC was grade I for all aneurysms in the follow-up angiography.

CONCLUSION

For main trunk aneurysms in the residual anterior circulation in MMD, although EVT was accompanied by potential ischemic and hemorrhagic complications, which should be considered, EVT can still offer an acceptable prognosis in more than 85% of patients.

Timing of Revascularization in Ischemic Moyamoya Disease: Association of Early Versus Delayed Surgery with Perioperative and Long-Term Outcomes

OBJECTIVE

Patients with nmoyamoya disease (MMD) who present primarily with ischemic stroke are known to have greater rates of perioperative strokes as compared with those who present with nonstroke symptoms. The optimal timing for revascularization for these patients remains unclear.

METHODS

From 1994 to 2015, 91 patients with MMD presented with signs and symptoms of an acute ischemic stroke with diffusion restriction correlate on magnetic resonance imaging, and these patients were subdivided into those who underwent early revascularization (<90 days from last stroke), versus those who underwent delayed revascularization (≥90 days after last stroke), based on evidence that most neurological recovery after stroke occurs during the first three months. Perioperative and long-term outcomes were compared between the 2 surgical cohorts.

RESULTS

In total, 27 patients underwent early revascularization, and 64 patients underwent delayed revascularization. Patients who underwent early revascularization had a statistically greater rate of perioperative stroke (P = 0.04) and perioperative mortality (P = 0.03), and overall complication rate (P = 0.049). At last follow-up of 5.2 ± 4.3 years, patients who underwent delayed revascularization had a lower mortality rate (P = 0.01) and a lower overall postoperative stroke incidence (P = 0.002). As a function of time, patients with MMD undergoing delayed revascularization had a statistically higher length of stroke-free survival (P = 0.005).

CONCLUSIONS

Patients with MMD who present with ischemic stroke are more likely to have perioperative strokes, overall perioperative complications, worse long-term mortality rates, and lower rates of stroke-free survival if revascularization surgery occurred within 90 days of last stroke.

Outcomes of Combined Revascularization Surgery for Moyamoya Disease without Preoperative Cerebral Angiography

OBJECTIVE

Cerebral angiography is the gold standard for diagnosing moyamoya disease (MMD), whereas magnetic resonance (MR) imaging/angiography is becoming more popular in the field of cerebrovascular disease due to its low invasiveness. Although there are concerns about using only MR imaging/angiography for preoperative analysis of MMD, considering the underestimation of pre-existing transdural collateral circulations and dangerous collaterals related to the risk of hemorrhage, we retrospectively reviewed our 10-year experience of MR imaging-first diagnosis and analyzed the perioperative outcomes.

METHODS

We analyzed 160 consecutive direct/indirect combined revascularization procedures for MMD preoperatively assessed using MR imaging/angiography alone. Perioperative complications were assessed for up to 2 weeks after surgery. Locations of the lesions responsible for complications were further classified into the surgical field, the ipsilateral hemisphere outside the surgical field, and the contralateral hemisphere.

RESULTS

Sixty-four revascularization procedures were performed in 38 children, and 96 procedures were performed in 68 adults. There was no difference in the incidence of perioperative ischemic complications between adults (6.3%) and pediatric patients (4.7%), but hemorrhagic complications were more frequently observed in adults (7.3%) than in children (0%) (P < 0.05). There was no specific lesion deviation for ischemic complications; however, hemorrhagic complications predominantly occurred in the surgical field.

CONCLUSIONS

Direct/indirect combined revascularization surgery based on our preoperative diagnostic protocol with the MR-first strategy resulted in favorable outcomes in pediatric MMD patients with relatively low complication rates. However, the validity of the MR-first diagnostic protocol should be further evaluated in adult patients with MMD.

A single - center retrospective observational study on patients undergoing Encephalo-Duro-Arterio -Myo-Synangiosis in patients with moyamoya disease

BACKGROUND:

Many cases of moyamoya disease are refractory to conventional medical therapy, hence surgical revascularization techniques have emerged as one of the primary choices of treatment. In this study, we present the functional and angiographic outcomes of patients undergoing encephalo-duro-arterio-myo-synangiosis (EDAMS).

METHODS:

This is a retrospective observational cohort study, done over 8 years (2012–2020) in a neurological center in Eastern India. Data were retrieved from the hospital's electronic system, recorded in a standard data abstract sheet, and analyzed.

RESULTS:

This study included 75 patients, with a male (n = 42; 56.0%) preponderance. Majority belonged to the pediatric age group (≤18 years) (n = 70; 93.3%); remaining adult population included 5 (6.6%) patients. The most common presenting complaint was that of an ischemic cerebrovascular accident (CVA) (n = 57; 76.0%). Symptomatic hemispheres (n = 69; 92.0%) were treated and later followed if they had progressed to bilateral disease formation. Preoperative DSA showed 50 (71.4%) to have Suzuki grade 3 type of angiographic findings. Postoperative complications included worsening unilateral hemiparesis 4 (40%), slurring of speech (n = 2; 20.0%), hematoma (n = 2; 20.0%), and surgical site infection (n = 2; 20.0%). One patient succumbed to his illness on the second postoperative day. A postoperative angiogram showed regression of moyamoya vessels in the majority (n = 69; 93.3%) of patients. All (n = 74; 100%) had an intensification of transdural vessels; none had a regression. None of the study participants showed an intensification of moyamoya vessels. Many of our patients (83.8%) had a good grade of revascularization (modified Matsushima and Inaba A and B), while 16.2% had low-grade revascularization (grade C). On assessing outcomes using a modified Rankin Score, a large number of our patients had an excellent (n = 45, 60%) neurological outcomes.

CONCLUSION:

There was a bimodal age distribution with most of them presenting with ischemic CVA. This procedure (EDAMS) had good angiographic (Matsushima and Inaba) and functional (modified Rankin Score) outcomes.

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

BACKGROUND

Transient neurological deficits (TNDs) develop after cerebral revascularization in patients with moyamoya disease (MMD). The authors report a rare pediatric MMD case with extensive decreased cerebral blood flow (CBF) and prolonged TNDs after combined revascularization.

OBSERVATIONS

A 9-year-old boy presented with transient left upper limb weakness, and MMD was diagnosed. A right-sided combined surgery was performed. Two years after the surgery, frequent but transient facial (right-sided) and upper limb weakness appeared. The left internal carotid artery terminal stenosis had progressed. Therefore, a left combined revascularization was performed. The patient’s motor aphasia and right upper limb weakness persisted for approximately 10 days after surgery. Magnetic resonance angiography showed that the direct bypass was patent, but extensive decreases in left CBF were observed using single photon emission tomography. With adequate fluid therapy and blood pressure control, the neurological symptoms eventually disappeared, and CBF improved.

LESSONS

The environment of cerebral hemodynamics is heterogeneous after cerebral revascularization for MMD, and the exact mechanism of CBF decreases was not identified. TNDs are significantly associated with the onset of stroke during the early postoperative period. Therefore, appropriate treatment is desired after determining complex cerebral hemodynamics using CBF studies.

Effects of end-tidal carbon dioxide levels in patients undergoing direct revascularization for Moyamoya disease and risk factors associated with postoperative complications

A history of transient ischemic attack, severity of disease, urinary output, hematocrit, hypocapnia, and hypotension during direct revascularization (superficial temporal artery to middle cerebral artery [STA-MCA]) in patients with Moyamoya disease (MMD) may lead to a poor prognosis, however, to our knowledge evidence for end-tidal carbon dioxide (ETCO2) targets is lacking. Within the ranges of standardized treatment, the article was primarily designed to study the risk factors associated with the neurologic outcomes during STA-MCA for MMD especially including ETCO2 ranges and the duration in different groups. The primary goals of this study were to investigate the risk factors for neurologic deterioration and explore the association between ETCO2 ranges and neurologic outcome during general anesthesia for STA-MCA.This retrospective observational study included 56 consecutively adult Moyamoya patients who underwent STA-MCA under general anesthesia between January 2015 and August 2019. ETCO2 was summarized per patient every 5 minutes. Clinical outcome was assessed with clinical presentation, computed tomography findings, magnetic resonance imaging findings, cerebral angiography, and the modified Rankin Scale scores at discharge as main outcome measure. The outcomes were also compared for the duration of surgery, anesthesia, and the length of stay.A total of 56 patients were studied, all patients had comprehensive ETCO2 measurements. The incidence of postoperative complications was 44.6% (25/56). There was no association between age, sex, hypertension, diabetes, smoking history, drinking history, sevoflurane use, invasive arterial blood pressure monitoring, combined encephalomyosynangiosis and postoperative complications. Duration of surgery (P = .04), anesthesia (P = .036), hospital stay (P = .023) were significant correlates of postoperative complications. In the multiple logistic regression model, they were not the significant predictors. The ETCO2 ranges and the length of time in different groups within the current clinical setting was not associated with postoperative complications (P > .05).Within a standardized intraoperative treatment strategy, we found that postoperative complications had no significant correlation with sex, age, hypertension, diabetes, smoking history, drinking history, invasive arterial blood pressure monitoring, combined encephalomyosynangiosis, or sevoflurane use. Further, hypocapnia and hypercapnia during STA-MCA were not found to be associated with postoperative complications in patients with MMD.

Revascularisation surgery for paediatric moyamoya disease: The Singapore experience

Moyamoya disease (MMD) is characterized by the spontaneous occlusion of the distal internal carotid arteries and resultant neo-angiogenesis of fragile collateral blood vessels. Direct and indirect revascularization surgeries have shown to effectively reduce stroke risks in paediatric MMD, whereby the latter is a more utilised technique in children. This study was undertaken to determine the outcomes of revascularization in Singapore's multi-ethnic, Southeast Asian paediatric population. This is an ethics-approved study conducted in Singapore's 2 tertiary children hospital units: KK Women's and Children's Hospital and National University Hospital. Sixteen patients with a diagnosis of ischaemic-type MMD are recruited between 01 January 2002 to 31 January 2019; and a total of 24 surgeries are undertaken (24 cerebral hemispheres). There are 2 cases of stroke within 30 days post-surgery. However, no stroke recurrence is observed beyond 30 days after surgery in all patients. Four patients reported recurrent transient ischaemic attack symptoms in the follow-up period ranging from 3 months to 12 years. Data analyses show a statistically significant improvement in modified Rankin's Scale (mMRS) in post-operative patients from baseline to discharge, and at 3 months after surgery. Our study also observes that predictors of recurrent ischaemic events include higher pre-operative MRS, Suzuki stage and perioperative infarction. To the authors' knowledge, this is the first study to date reporting the outcomes of revascularisation in a paediatric Southeast Asian cohort.

Complications following Encephalo-Duro-Arterio-Myo-Synangiosis in a case of Moyamoya disease

We report a case of an 18-year-old girl diagnosed to have Moyamoya disease (MMD), who underwent bilateral encephalo-duro-arterio-myo-synangiosis. Literature search has clearly inferred that in comparison to an adult patient, children with MMD can have a good prognosis if early diagnosis and active surgical intervention are achieved. Evidence has demonstrated that active surgical management, including indirect bypass surgery, may improve the cerebral circulation on a relatively larger scale than direct bypass surgeries, which can only improve the cerebral circulation in the area of the vascular reconstruction.

Postoperative Symptomatic Cerebral Infarction in Pediatric Moyamoya Disease: Risk Factors and Clinical Outcome

BACKGROUND

Indirect bypass surgery is used to improve the hemodynamic status of pediatric patients with moyamoya disease (MMD). Symptomatic cerebral infarction during the early postoperative period may be the most frustrating complication. This study was conducted to investigate the factors associated with early postoperative symptomatic cerebral infarction.

METHODS

Between January 2000 and February 2014, we performed 1241 indirect bypass surgeries in 659 pediatric MMD patients. Symptomatic infarction during the early postoperative period was diagnosed in 63 operations in 61 patients.

RESULTS

The overall incidence of symptomatic cerebral infarction after indirect bypass surgery was 5.1%. The median age of the patients with postoperative infarction was 6 years (mean, 6.4 years; range, 1-15 years). The performance of 2 craniotomies in single operation was associated with a higher rate of cerebral infarction. Moreover, the incidence was higher in young patients (age <6 years) compared with older patients. In a matched analysis, an immediate postoperative hemoglobin level >13 g/dL was associated with decreased risk of infarction (odds ratio, 0.144; P = 0.003). Mutation of the methylenetetrahydrofolate reductase (MTHFR) gene occurred in a relatively high proportion of our infarction cohort.

CONCLUSIONS

Postoperative symptomatic infarctions can occur despite a unified surgical method and formulaic perioperative management protocol. Patient-centered factors, such as young age, genetic background of MTHFR, and certain medical conditions, including hyperthyroidism, renovascular hypertension, and hemolytic uremic syndrome, as well as management-related factors, including 2 craniotomies and low immediate postoperative hemoglobin level, could be risk factors for early postoperative symptomatic cerebral infarction.

Risk factors for postoperative stroke in adults patients with moyamoya disease: a systematic review with meta-analysis

Background

This systematic review and meta-analysis aimed to clarify the risk factors for postoperative stroke in adult patients with moyamoya disease (MMD).

Methods

We comprehensively searched MEDLINE/PubMed, Web of Science, and Cochrane Library for eligible published literature with regard to the risk factors and postoperative complications in adult patients with MMD. Statistical analysis was conducted using Stata version 12.0. Pooled odds ratio (OR) with 95% confidence interval (CI) were assessed for each risk factor.

Results

There were 8 studies encompassing 1649 patients who underwent surgery with MMD were selected for analysis. Preoperative ischemic event significantly increase the risk of postoperative stroke events (OR = 1.40; 95%CI = 1.02–1.92; P = 0.039). PCA involvement correlate with an increased risk of post-infarction (OR = 4.60; 95%CI = 2.61–8.11; P = 0.000). Compared to direct bypass, patients who underwent indirect bypass or combined bypass could significantly increase the risk of postoperative stroke events. (OR = 1.17; 95%CI = 1.03–1.33; p = 0.017). MMD patients with diabetes were associated with an increased risk of postoperative stroke events (OR = 4.02, 95% CI = 1.59–10.16; p = 0.003). MMD patients with hypertension, age at onset and male sex were not associated with an increased risk of postoperative stroke events (P > 0.05).

Conclusions

This systematic review and meta-analysis indicated that preoperative ischemic events, PCA involvement and diabetes were independent risk factors for postoperative stroke in MMD patients. Therefore, in order to ensure the curative effect of patients with MMD, it is very necessary to detect these risk factors and prevent postoperative complications in time.

Novel Indirect Revascularization Technique with Preservation of Temporal Muscle Function for Moyamoya Disease Encephalo-Duro-Fascio-Arterio-Pericranial-Synangiosis: A Case Series and Technical Note

BACKGROUND

Direct and/or indirect bypass surgery is the established approach for preventing stroke in patients with moyamoya disease. However, conventional indirect revascularization, including encephalo-myo-synangiosis, has some disadvantages associated with the mass effect of the temporal muscle under the bone flap and postsurgical depression in the temporal region. We devised a novel indirect revascularization method, using only the temporal fascia, to address the aforementioned disadvantages.

METHODS

A skin incision was performed along the superficial temporal artery. The temporal fascia was cut such that the base of the fascia flap was on the posterior side. The fascia and temporal muscles were dissected separately. After turning over the fascia, the muscle was cut such that the base of the muscle flap was on the anterior side. Craniotomy, direct bypass, and encephalo-duro-synangiosis were performed conventionally. Only the temporal fascia was used for indirect revascularization and duraplasty. The muscle was replaced in the anatomically correct position after replacing the bone flap.

RESULTS

We performed the aforementioned surgery on 18 (13 women and 5 men) consecutive patients (21 cerebral hemispheres) enrolled between 2012 and 2016. The average age was 28.7 years. The mean follow-up period was 31.6 months. In 17 patients (94%), the symptoms and cerebral blood flow improved. Digital subtraction angiography showed satisfactory angiogenesis from the temporal fascia. Depression in the temporal region and atrophy of the temporal muscle were negligible.

CONCLUSIONS

This surgical technique provides good clinical and cosmetic outcomes. It may also be one of the good surgical treatments available for symptomatic moyamoya disease.

Risk Factors Associated with Neurologic Deterioration After Combined Direct and Indirect Revascularization in Patients with Moyamoya Disease on the East Coast of China

OBJECTIVE

Neurologic deterioration is the primary distinctive complication after revascularization surgery in patients with moyamoya disease (MMD). The present study investigated the risk factors for neurologic deterioration after combined direct and indirect revascularization in patients with MMD.

METHODS

A retrospective review of 123 patients with MMD undergoing 138 combined direct and indirect revascularization procedures was performed. Demographics, clinical manifestation, medical history, neurologic deterioration complications, and relevant information of the operation were recorded.

RESULTS

There were 25 (18.12%) postoperative neurologic deterioration complications (13 reversible neurologic deficits, 9 infarctions with neurologic sequelae, and 3 hemorrhages). Preoperative multiple symptom episodes and one-staged bilateral revascularization were significantly correlated with postoperative neurologic deterioration complications (P < 0.05 and P < 0.01, respectively). The incidence rate (26.39%) of postoperative neurologic deterioration in ischemic MMDs was significantly greater than hemorrhagic MMDs (7.69%; P < 0.01) In total, 34.78% of patients with transient ischemic attack onset and 22.45% of patients with infarction onset suffered from postoperative neurologic deterioration, and there was no significant difference between them (P > 0.05). Postoperative neurologic deterioration complications had no significant correlation with sex, age at the time of surgery, type of surgical procedure, unilateral MMD or not, interval between the last attack and operation, and history of thyroid disease, hypertension, and autoimmune disease.

CONCLUSIONS

Preoperative multiple symptom episodes and one-staged bilateral revascularization are risk factors associated with postoperative neurologic deterioration in patients with MMD. Therefore, 2 unilateral revascularization procedures performed successively rather than one-staged bilateral revascularization procedures should be performed in patients with bilateral MMD.

Chronologic Evaluation of Cerebral Hemodynamics by Dynamic Susceptibility Contrast Magnetic Resonance Imaging After Indirect Bypass Surgery for Moyamoya Disease

OBJECTIVE

Although indirect bypass surgery is an effective treatment option for patients with ischemic-onset moyamoya disease (MMD), the time point after surgery at which the patient's hemodynamic status starts to improve and the time point at which the improvement reaches a maximum have not been known. The objective of the present study is to evaluate the hemodynamic status time course after indirect bypass surgery for MMD, using dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI).

METHODS

We retrospectively analyzed the cases of 25 patients with MMD (37 sides; mean age, 14.7 years; range, 3-36 years) who underwent indirect bypass surgery and repeated DSC-MRI measurement within 6 months after the operation. The difference in the mean transit time (MTT) between the target regions and the control region (cerebellum) was termed the MTT delay, and we measured the MTT delay's chronologic changes after surgery.

RESULTS

The postoperative MTT delay was 1.81 ± 1.16 seconds within 1 week after surgery, 1.57 ± 1.01 at weeks 1-2, 1.55 ± 0.68 at weeks 2-4, 1.32 ± 0.68 at months 1-2, 0.95 ± 0.32 at months 2-3, and 0.77 ± 0.33 at months 3-6. Compared with the preoperative value (2.11 ± 0.98 seconds), the MTT delay decreased significantly from 2 to 4 weeks after surgery (P < 0.05).

CONCLUSIONS

The amelioration of cerebral hemodynamics by indirect bypass surgery began soon after surgery and gradually reached a maximum at 3 months after surgery. DSC-MRI detected small changes in hemodynamic improvement, which are suspected to be caused by the initiation of angiogenesis and arteriogenesis in the early postoperative period.

Revascularization of Moyamoya Angiopathy in Older Adults

BACKGROUND

Moyamoya angiopathy most often manifests in patients in the second and third decades of life. Although uncommon, it can also manifest later in life. We present our results in patients >50 years old with moyamoya angiopathy who were treated with surgical revascularization via either direct bypass or indirect bypass (encephaloduroarteriosynangiosis).

METHODS

A retrospective review was conducted to identify patients with moyamoya disease who were treated with surgical revascularization at our institution between 2002 and 2015. Outcomes and complications were analyzed.

RESULTS

We identified 33 patients with moyamoya angiopathy >50 years old (mean age 59.0 years ± 7.6) who were treated with surgical revascularization of 45 affected hemispheres. Of the affected hemispheres, 27 (60%) were treated with indirect bypasses and 18 (40%) were treated with direct bypasses. Neurologic complications occurred in 4 (12%) patients. The mean length of follow-up was 18.7 months ± 18.6; 4 patients were lost to follow-up. At last follow-up, 11 of 18 (61%) direct bypasses were patent. Treatment failed in 5 of 45 (11%) treated hemispheres (stroke in 2 and persistent transient ischemic attacks in 3). In terms of functional outcome at last follow-up, 16 of 29 (55%) patients were the same as before surgery, 10 (35%) were better, and 3 (10%) were worse (including 1 death).

CONCLUSIONS

Although uncommon, moyamoya angiopathy can manifest in older adults. Surgical revascularization is a reasonable treatment option with good functional outcomes and an acceptable complication rate.

Direct versus indirect revascularization procedures for moyamoya disease: a comparative effectiveness study

OBJECTIVE Moyamoya disease (MMD) is a chronic cerebrovascular disease that can lead to devastating neurological outcomes. Surgical intervention is the definitive treatment, with direct, indirect, and combined revascularization procedures currently employed by surgeons. The optimal surgical approach, however, remains unclear. In this decision analysis, the authors compared the effectiveness of revascularization procedures in both adult and pediatric patients with MMD. METHODS A comprehensive literature search was performed for studies of MMD. Using complication and success rates from the literature, the authors constructed a decision analysis model for treatment using a direct and indirect revascularization technique. Utility values for the various outcomes and complications were extracted from the literature examining preferences in similar clinical conditions. Sensitivity analysis was performed. RESULTS A structured literature search yielded 33 studies involving 4197 cases. Cases were divided into adult and pediatric populations. These were further subdivided into 3 different treatment groups: indirect, direct, and combined revascularization procedures. In the pediatric population at 5- and 10-year follow-up, there was no significant difference between indirect and combination procedures, but both were superior to direct revascularization. In adults at 4-year follow-up, indirect was superior to direct revascularization. CONCLUSIONS In the absence of factors that dictate a specific approach, the present decision analysis suggests that direct revascularization procedures are inferior in terms of quality-adjusted life years in both adults at 4 years and children at 5 and 10 years postoperatively, respectively. These findings were statistically significant (p < 0.001 in all cases), suggesting that indirect and combination procedures may offer optimal results at long-term follow-up.

Risk Factors for Newly Developed Cerebral Infarction After Surgical Revascularization for Adults with Moyamoya Disease

OBJECTIVE

It is important to recognize the incidence and risk factors for ischemic complications after surgical revascularization for moyamoya disease (MMD). However, most studies focus on pediatric MMD or pediatric and adult MMD. Our study identified the incidence and risk factors of newly developed cerebral infarction after surgical revascularization for adult MMD.

METHODS

Ischemic complications were defined as newly developed cerebral infarction within 15 days after surgery, as identified by imaging studies. To identify the incidence and these risk factors for adult patients ≥18 years, we retrospectively reviewed our experience with 194 adult MMD patients with 241 surgical revascularizations.

RESULTS

The incidence of symptomatic infarction after surgical revascularization was 5.8% (14 cases); 30 cases (12.4%) experienced a silent infarction. In univariate analysis, initial presentation as infarction, initial presentation as hemorrhage, transient ischemic attacks (TIAs) >3 times/month, involvement of the posterior cerebral artery (PCA), combined bypass, and using muscle for revascularization were variables related to the newly developed cerebral infarction. Multivariate analysis revealed that the following factors were independently associated with newly developed cerebral infarction after surgery: cerebral infarction as initial presentation (odds ratio [OR] 1.150; 95% confidence interval [CI] 1.038-1.273; P = 0.0073), TIAs >3times/month (OR 1.188; 95% CI 1.058-1.335; P = 0.0035), and PCA involvement (OR 1.095; 95% CI 1.005-1.194; P = 0.039).

CONCLUSIONS

Our findings demonstrate that newly developed, silent cerebral infarction developed more frequently than symptomatic cerebral infarction in adult patients. Cerebral infarction as initial presentation, frequent TIA before surgery, and PCA involvement were also independent risk factors for newly developed cerebral infarction after surgical revascularization for adult MMD.

Clinical implications of the cortical hyperintensity belt sign in fluid-attenuated inversion recovery images after bypass surgery for moyamoya disease

OBJECTIVE Transient neurological symptoms are frequently observed during the early postoperative period after direct bypass surgery for moyamoya disease. Abnormal signal changes in the cerebral cortex can be seen in postoperative MR images. The purpose of this study was to reveal the radiological features of the "cortical hyperintensity belt (CHB) sign" in postoperative FLAIR images and to verify its relationship to transient neurological events (TNEs) and regional cerebral blood flow (rCBF). METHODS A total of 141 hemispheres in 107 consecutive patients with moyamoya disease who had undergone direct bypass surgery were analyzed. In all cases, FLAIR images were obtained during postoperative days (PODs) 1-3 and during the chronic period (3.2 ± 1.13 months after surgery). The CHB sign was defined as an intraparenchymal high-intensity signal within the cortex of the surgically treated hemisphere with no infarction or hemorrhage present. The territory of the middle cerebral artery was divided into anterior and posterior parts, with the extent of the CHB sign in each part scored as 0 for none; 1 for presence in less than half of the part; and 2 for presence in more than half of the part. The sum of these scores provided the CHB score (0-4). TNEs were defined as reversible neurological deficits detected both objectively and subjectively. The rCBF was measured with SPECT using N-isopropyl-p-[¹²³I]iodoamphetamine before surgery and during PODs 1-3. The rCBF increase ratio was calculated by comparing the pre- and postoperative count activity. RESULTS Cortical hyperintensity belt signs were detected in 112 cases (79.4%) and all disappeared during the chronic period. Although all bypass grafts were anastomosed to the anterior part of the middle cerebral artery territory, CHB signs were much more pronounced in the posterior part (p < 0.0001). TNEs were observed in 86 cases (61.0%). Patients with TNEs showed significantly higher CHB scores than those without (2.31 ± 0.13 vs 1.24 ± 0.16, p < 0.0001). The CHB score, on the other hand, showed no relationship with the rCBF increase ratio (p = 0.775). In addition, the rCBF increase ratio did not differ between those patients with TNEs and those without (1.15 ± 0.033 vs 1.16 ± 0.037, p = 0.978). CONCLUSIONS The findings strongly suggest that the presence of the CHB sign during PODs 1-3 can be a predictor of TNEs after bypass surgery for moyamoya disease. On the other hand, presence of this sign appears to have no direct relationship with the postoperative local hyperperfusion phenomenon. Vasogenic edema can be hypothesized as the pathophysiology of the CHB sign, because the sign was transient and never accompanied by infarction in the present series.

Voxel Based Analysis of Surgical Revascularization for Moyamoya Disease: Pre- and Postoperative SPECT Studies

Moyamoya disease (MMD) is a chronic, progressive, cerebrovascular occlusive disease that causes abnormal enlargement of collateral pathways (moyamoya vessels) in the region of the basal ganglia and thalamus. Cerebral revascularization procedures remain the preferred treatment for patients with MMD, improving the compromised cerebral blood flow (CBF). However, voxel based analysis (VBA) of revascularization surgery for MMD based on data from pre- and postoperative data has not been established. The latest algorithm called as Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) has been introduced for VBA as the function of statistical parametric mapping (SPM8), and improved registration has been achieved by SPM8 with DARTEL. In this study, VBA was conducted to evaluate pre- and postoperative single photon emission computed tomography (SPECT) images for MMD by SPM8 with DARTEL algorithm, and the results were compared with those from SPM8 without DARTEL (a conventional method). Thirty-two patients with MMD who underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery as the first surgery were included and all patients underwent pre- and postoperative 3D T1-weighted imaging and SPECT. Pre- and postoperative SPECT images were registered to 3D T1-weighted images, then VBA was conducted. Postoperative SPECT showed more statistically increased CBF areas in the bypassed side cerebral hemisphere by using SPM8 with DARTEL (58,989 voxels; P<0.001), and increased ratio of CBF after operation was less than 15%. Meanwhile, postoperative SPECT showed less CBF increased areas by SPM8 without DARTEL. In conclusion, VBA was conducted for patients with MMD, and SPM8 with DARTEL revealed that postoperative SPECT showed statistically significant CBF increases over a relatively large area and with at most 15% increase ratio.

Long term outcome and predictors of ischemic stroke recurrence in adult moyamoya disease

OBJECTIVE

We sought to identify the clinical outcome and predictors for ischemic stroke recurrence in adults with symptomatic moyamoya disease (MMD).

METHODS

We analyzed 104 adult MMD patients with ischemic stroke or TIA registered at our institution. All patients underwent digital subtraction angiography and single photon emission computed tomography to measure disease severity and cerebral vascular reserve (CVR). A Cox regression model was used to identify predictors of recurrent ischemic stroke.

RESULTS

Fifty-nine patients were non-surgically treated and 45 patients were surgically treated. In the non-surgical group, the Kaplan-Meier estimate of ischemic stroke recurrence was 1.6% in the first year and 11.8% in the 5th year. Hypertension (hazard ratio [HR]=0.07, 95% confidence interval [CI] 0.01-0.99), diabetes (HR=35.16, 95% CI 2.61-474.16), presence of steno-occlusive lesion in posterior cerebral arteries (HR=17.53, 95% CI 2.02-152.43), and extended or global decreased CVR (HR=13.62, 95% CI 1.55-119.84) were independent predictors of recurrence. In the surgical group, the Kaplan-Meier estimate of ischemic stroke recurrence was 24.4% in the first year and 24.4% in the 5th year. Half of the recurred patients experienced recurrent ischemic strokes postoperatively. Diabetes was the only predictor of recurrent ischemic stroke (HR=6.17, 95% CI 1.31-29.14).

CONCLUSIONS

In non-surgically treated MMD, PCA stenosis and CVR were identified as predictors of ischemic stroke recurrence. Diabetes was an independent predictor of recurrent ischemic stroke in both non-surgical and surgically treated MMD groups.

Cognitive Outcome of Pediatric Moyamoya Disease

Quality of life is the current trend and issue for the most of human diseases. In moyamoya disease (MMD), surgical revascularization has been recognized as the possible assistance to reduce the neurological insult. However, the progressive nature of the disease has been invincible so far. To improve the quality of life of MMD patients not only the protection from the neurological insult but also the maintenance or improvement of cognitive function is inevitable. For pediatric MMD patients, younger age or longer duration of disease is the key factor among the prognostic factors for bad neurological outcomes. Hence, 'the earlier, the better' is the most precious rule for treatment. Protection from neurological insult is very critical and foremost important to improve cognitive outcome. Clinicians need to know the neuropsychological profile of MMD patients for the care of whole person and make an effort to protect the patients from neurological insults to maintain or improve it.

The frequency of postoperative stroke in moyamoya disease following combined revascularization: a single-university series and systematic review

Object

Although combined direct and indirect anastomosis in patients with moyamoya disease immediately increases cerebral blood flow, the surgical procedure is more complex. Data pertinent to the postoperative complications associated with combined bypass are relatively scarce compared with those associated with indirect bypass. This study investigated the incidence and characteristics of postoperative stroke in combined bypass and compared them with those determined from a literature review to obtain data from a large population.

Methods

A total of 358 revascularization procedures in 236 patients were retrospectively assessed by reviewing clinical charts and radiological data. PubMed was searched for published studies on surgical treatment to determine the incidence of postoperative complications in a larger population.

Results

Seventeen instances of postoperative stroke were observed in 16 patients (4.7% per surgery, 95% CI 2.8%–7.5%). Postoperative stroke was more frequent (7.9% per surgery) in adults than in pediatric patients (1.7% per surgery, OR 4.07, 95% CI 1.12–14.7; p < 0.05). Acute progression of stenoocclusive changes were identified in the major cerebral arteries (anterior cerebral artery, n = 3; middle cerebral artery, n = 1; posterior cerebral artery, n = 2). The postoperative stroke rate was comparable with that (5.4%) determined from a literature search that included studies reporting more than 2000 direct/combined procedures. No differences in the stroke rates between the direct/combined and indirect procedures were found. In the literature review, direct/combined bypass was more often associated with excellent revascularization (angiographic opacification greater than two-thirds) than indirect bypass (p < 0.05).

Conclusions

This experience of 358 consecutive procedures is one of the largest series for which the postoperative stoke rate for direct/combined bypass performed with a unified strategy has been reported. A systematic review confirmed that the postoperative stroke rate for the direct/combined procedure was comparable to that for the indirect procedure.

Surgical outcomes for moyamoya angiopathy at barrow neurological institute with comparison of adult indirect encephaloduroarteriosynangiosis bypass, adult direct superficial temporal artery-to-middle cerebral artery bypass, and pediatric bypass: 154 revascularization surgeries in 140 affected hemispheres

BACKGROUND

Untreated, moyamoya angiopathy is a progressive vaso-occlusive process that can lead to ischemic or hemorrhagic stroke.

OBJECTIVE

To review 1 institution's surgical experience with both direct and indirect bypass (encephaloduroarteriosynangiosis) in adult and pediatric groups.

METHODS

A retrospective review was conducted of a consecutive series of patients treated for moyamoya angiopathy between 1995 and 2009.

RESULTS

Thirty-nine adult patients underwent indirect bypass as their initial therapy; 29 adult patients underwent direct bypass. Twenty-four pediatric patients included 20 indirect bypasses and 4 direct bypasses. Overall, 140 hemispheres were treated; 48 patients received revascularization of both hemispheres. There were 14 additional revascularization procedures (10% per hemisphere) performed over a site of continued hypoperfusion postoperatively. Fourteen postoperative ischemic strokes occurred during the entire follow-up (10% per hemisphere), and the Kaplan-Meier analysis was not significantly different between groups (P = .59). Four grafts (9.09%) had failed at radiographic follow-up of the 44 direct bypasses performed. Before the initial surgery, the modified Rankin Scale score was 1.58 ± 0.93, 1.48 ± 0.74, and 1.8 ± 1.1 in the pediatric, adult direct, and adult indirect groups (P = .39). At last follow-up, it was 1.29 ± 1.31, 1.09 ± 0.90, and 1.94 ± 1.51 (P = .04) in the pediatric, adult direct, and adult indirect groups.

CONCLUSION

This series demonstrates that both direct and indirect bypasses can be equally effective in preventing stroke. However, in adult patients, direct bypass patients had significantly greater improvement in symptoms, as seen in modified Rankin Scale scores. Pediatric patients, despite undergoing predominantly indirect bypasses, fared roughly the same as the adults in the direct bypass group.

Clinical features, surgical treatment and long-term outcome in adult patients with Moyamoya disease in China

BACKGROUND

Moyamoya disease (MMD) develops mostly in Asian countries including Japan, Korea, mainland China and Taiwan. However, there are few detailed demographic and clinical data about Chinese patients with MMD. Currently, the most effective treatment in adult patients with MMD is unknown. There have only been a few small case series reporting on encephaloduroarteriosynangiosis (EDAS) in an adult population. Here we describe the clinical features, surgical treatment and long-term outcome of adults with MMD treated at a single institution in China.

METHODS

Our cohort included 470 adult patients with MMD. The demographic and clinical characteristics were obtained by retrospective chart review and long-term outcome was evaluated using the stroke status. The modified Rankin Scale (mRS) was used to determine the neurological functional outcome. Univariate and multivariate logistic regression analyses were performed to determine risk factors for postoperative morbidity and functional outcome. The risk of subsequent stroke was determined using the Kaplan-Meier method and Cox regression was used to determine risk factors for postoperative or subsequent strokes.

RESULTS

The median age for the onset of symptoms was 36.8 (range, 18-59) years. The ratio of female to male patients was 1:1 (231/239). Familial occurrence of MMD was 2.3%. The most common initial symptom was a cerebral ischemic event. The incidence of postoperative ischemic events or hemorrhage was 5.9% (9.8% of patients). Older age at symptom onset, posterior cerebral artery (PCA) involvement and the presence of transient ischemic attack (TIA) were identified as predictors of adverse postoperative events. The Kaplan-Meier estimate stroke risk was 10.1% in the first 2 years, and the 5-year Kaplan-Meier risk of stroke was 13% after surgery for all patients treated with surgical revascularization. Older age at symptom onset, PCA involvement and the presence of TIA were identified as predictors of postoperative or subsequent strokes. Overall, 73.2% of patients had an independent life with no significant disability, with the strongest predictor being the preoperative mRS score.

CONCLUSION

Clinical characteristics of adult MMD in China are different from those in other Asian countries. EDAS in adult patients with MMD carries a low risk, is effective at preventing future ischemic events and improves quality of life.

Moyamoya disease: functional and neurocognitive outcomes in the pediatric and adult populations

OBJECT

Moyamoya disease is an occlusive cerebrovascular disorder commonly resulting in neurocognitive impairment. The cognitive outcome parameters commonly affected are intelligence, memory, executive function, and quality of life. In this paper, the authors review the existing literature on cognitive and clinical outcomes in adult and pediatric moyamoya populations separately.

METHODS

A systematic review of the cognitive and clinical outcome literature was performed using the PubMed/MEDLINE database. Outcomes data were contrasted between adult and pediatric populations.

RESULTS

Intelligence is the main cognitive outcome parameter affected in pediatric patients with moyamoya disease, whereas adults most commonly suffer from executive function impairment. Memory has not been studied sufficiently in pediatric patients, and its dysfunction in the adult population remains controversial. Quality of life has not been studied appropriately in either population. Surgical revascularization is the only beneficial treatment option, and a combination of direct and indirect bypass techniques has shown benefit, but the impact on the above-mentioned parameters has not been sufficiently elucidated.

CONCLUSIONS

Moyamoya disease affects the cognition and daily function in pediatric patients to a greater extent than in adult patients. Due to the rarity of the disease, there is a distinct lack of high-level evidence regarding cognitive and clinical outcomes.

Ischemic complications occurring in the contralateral hemisphere after surgical treatment of adults with moyamoya disease

OBJECTIVE

Direct revascularization surgery is regarded as the most effective method of treatment of adults with moyamoya disease. These patients, however, have a higher risk of perioperative ischemic complications than do patients with atherosclerotic stroke, and are at risk for ischemic complications in the hemisphere contralateral to the one operated on. We investigated the incidence and risk factors for ischemic stroke in the contralateral hemisphere after surgical treatment of adults with moyamoya disease.

METHODS

We retrospectively reviewed the medical records and results of neuroimaging studies on 79 hemispheres of 73 consecutive patients with adult moyamoya disease (mean±SD age, 37.96±11.27 years; range, 18-62 years) who underwent direct bypass surgery over 6 years.

RESULTS

Ischemic complications occurred in 4 of 79 (5.1%) contralateral hemispheres, one with Suzuki stage 3 and three with Suzuki stage 4. Three patients showed posterior cerebral artery (PCA) involvement by moyamoya vessels. Advanced stage of moyamoya disease (Suzuki stages 4/5/6; p=0.001), PCA involvement (p=0.001) and postoperative hypotension (mean arterial blood pressure <80% of preoperative mean arterial blood pressure) on the first (p<0.0001) and second (p=0.003) days after surgery were significantly correlated with postoperative contralateral ischemic complications.

CONCLUSION

In patients with advanced moyamoya disease and involvement of the PCA, intentional hypotension can result in ischemic stroke in the hemisphere contralateral to the one operated on. Careful control of perioperative blood pressure is crucial for good surgical results.

Unpredictable postoperative global cerebral infarction in the patient of williams syndrome accompanying moyamoya disease

We report a rare case of Williams syndrome accompanying moyamoya disease in whom postoperative global cerebral infarction occurred unpredictably. Williams syndrome is an uncommon hereditary disorder associated with the connective tissue abnormalities and cardiovascular disease. To our knowledge, our case report is the second case of Williams syndrome accompanying moyamoya disease. A 9-year-old boy was presented with right hemiparesis after second operation for coarctation of aorta. He was diagnosed as having Williams syndrome at the age of 1 year. Brain MRI showed left cerebral cortical infarction, and angiography showed severe stenosis of bilateral internal carotid arteries and moyamoya vessels. To reduce the risk of furthermore cerebral infarction, we performed indirect anastomosis successfully. Postoperatively, the patient recovered well, but at postoperative third day, without any unusual predictive abnormal findings the patient's pupils were suddenly dilated. Brain CT showed the global cerebral infarction. Despite of vigorous treatment, the patient was not recovered and fell in brain death one week later. We suggest that in this kind of labile patient with Williams syndrome accompanying moyamoya disease, postoperative sedation should be done with more thorough strict patient monitoring than usual moyamoya patients. Also, we should decide the revascularization surgery more cautiously than usual moyamoya disease. The possibility of unpredictable postoperative ischemic complication should be kept in mind.

Incidence and Pathogenesis of Transient Cheiro-Oral Syndrome After Surgical Revascularization for Moyamoya Disease

BACKGROUND:

There are no reports that denote transient cheiro-oral syndrome (COS) after surgical revascularization for moyamoya disease.

OBJECTIVE:

To clarify the incidence and pathogenesis of transient COS after surgical revascularization for moyamoya disease.

METHODS:

This study included 21 patients who underwent superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and indirect bypass because of Moyamoya disease. Their medical records were evaluated to identify clinical features of postoperative transient COS. The findings on MRI, magnetic resonance angiography, and single-photon emission computed tomography were also analyzed.

RESULTS:

Transient COS developed in 8 (22.9%) of 35 operated hemispheres, or in 6 (28.6%) of 21 patients between 3 and 20 days after surgery. Most of the COS were associated with mild weakness of the ipsilateral face and hand. Simultaneous radiological studies detected no findings of cerebral infarct or postoperative hyperperfusion. STA-MCA anastomosis was patent in all patients. However, their disease stage more frequently progressed owing to considerable blood flow via STA-MCA anastomosis, and basal moyamoya vessels disappeared or diminished in patients with transient COS rather than in those without.

CONCLUSION:

Transient COS after surgical revascularization for moyamoya disease is not rare. Bypass flow through STA-MCA anastomosis may stimulate a rapid progression of disease stage and diminish basal moyamoya vessels, causing transient COS within 3 weeks after surgery.

Novel Bypass Surgery for Moyamoya Disease Using Pericranial Flap: Its Impacts on Cerebral Hemodynamics and Long-term Outcome

OBJECTIVE

We reviewed our 11-year experience with a novel bypass procedure, superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and encephalo-duro-myo-arterio-pericranio-synangiosis (EDMAPS), for moyamoya disease regarding cerebral hemodynamics and long-term outcome.

METHODS

This prospective study included 75 patients with moyamoya disease, including 28 children and 47 adults. We performed STA-MCA anastomosis and EDMAPS on 123 hemispheres of 75 patients. In addition to conventional STA-MCA anastomosis and indirect bypass for the MCA territory, the medial frontal lobe was revascularized using the frontal pericranial flap through medial frontal craniotomy. Surgical results were analyzed with magnetic resonance imaging, cerebral angiography, and single-photon emission computed tomography/positron emission tomography.

RESULTS

Overall incidences of mortality and morbidity were 0% and 5.7%, respectively. The annual risk of cerebrovascular events during the follow-up periods was very low: 0% in pediatric patients and 0.4% in adults over approximately 67 months. Postoperative cerebral angiography showed that the pericranial flap functioned well as donor tissue for indirect bypass, especially in pediatric patients. Follow-up single-photon emission computed tomography/positron emission tomography studies revealed that cerebral blood flow and its reactivity to acetazolamide markedly improved in both the MCA and anterior cerebral artery territories.

CONCLUSION

These findings strongly suggest that STA-MCA anastomosis and EDMAPS using a frontal pericranial flap is a safe and effective surgical procedure to further improve the long-term prognosis in moyamoya disease by improving cerebral hemodynamics in both the MCA and anterior cerebral artery territories.

Clinical implications of intraoperative infrared brain surface monitoring during superficial temporal artery-middle cerebral artery anastomosis in patients with moyamoya disease

OBJECT

Surgical revascularization for moyamoya disease prevents cerebral ischemic attacks by improving cerebral blood flow (CBF). Symptomatic cerebral hyperperfusion is a potential complication of this procedure, but its treatment is contradictory to that for ischemia. Because intraoperative techniques to detect hyperperfusion are still lacking, the authors performed intraoperative infrared monitoring in moyamoya disease using a novel infrared imaging system.

METHODS

During superficial temporal artery-middle cerebral artery anastomosis in 25 patients (26 hemispheres) with moyamoya disease, the authors monitored the brain surface temperature intraoperatively with the IRIS-V infrared imaging system. The average gradation value change (indicating temperature change) was calculated using commercial software. Magnetic resonance imaging, MR angiography, and N-isopropyl-p-[(123)I]iodoamphetamine SPECT studies were performed routinely before and within 10 days after surgery.

RESULTS

Patency of bypass, detailed local hemodynamics, and changes in cortical surface temperature around the anastomosis site were well recognized by the IRIS-V infrared imaging system in all cases. In the present study, 10 patients suffered transient neurological symptoms accompanied by an increase in CBF around the anastomosis site, recognized as symptomatic hyperperfusion. The increase in temperature was significantly higher in these patients. Intensive blood pressure control was undertaken, and free-radical scavengers were administered. No patient in the present study suffered a permanent neurological deficit.

CONCLUSIONS

Although the present method does not directly monitor surface CBF, temperature rise around the anastomosis site during surgery might be an indicator of postoperative hyperperfusion. Prospective evaluation with a larger number of patients is necessary to validate this technique.

Clinical outcome after 450 revascularization procedures for moyamoya disease

Object

Moyamoya disease (MMD) is a rare cerebrovascular disease mainly described in the Asian literature. To address a lack of data on clinical characteristics and long-term outcomes in the treatment of MMD in North America, the authors analyzed their experience at Stanford University Medical Center. They report on a consecutive series of patients treated for MMD and detail their demographics, clinical characteristics, and long-term surgical outcomes.

Methods

Data obtained in consecutive series of 329 patients with MMD treated microsurgically by the senior author (G.K.S.) between 1991 and 2008 were analyzed. Demographic, clinical, and surgical data were prospectively gathered and neurological outcomes assessed in postoperative follow-up using the modified Rankin Scale. Association of demographic, clinical, and surgical data with postoperative outcome was assessed by chi-square, uni- and multivariate logistic regression, and Kaplan-Meier survival analyses.

Results

The authors treated a total of 233 adult patients undergoing 389 procedures (mean age 39.5 years) and 96 pediatric patients undergoing 168 procedures (mean age 10.1 years). Direct revascularization technique was used in 95.1% of adults and 76.2% of pediatric patients. In 264 patients undergoing 450 procedures (mean follow-up 4.9 years), the surgical morbidity rate was 3.5% and the mortality rate was 0.7% per treated hemisphere. The cumulative 5-year risk of perioperative or subsequent stroke or death was 5.5%. Of the 171 patients presenting with a transient ischemic attack, 91.8% were free of transient ischemic attacks at 1 year or later. Overall, there was a significant improvement in quality of life in the cohort as measured using the modified Rankin Scale (p < 0.0001).

Conclusions

Revascularization surgery in patients with MMD carries a low risk, is effective at preventing future ischemic events, and improves quality of life. Patients in whom symptomatic MMD is diagnosed should be offered revascularization surgery.

Understanding and treating moyamoya disease in children

Moyamoya disease, a known cause of pediatric stroke, is an unremitting cerebrovascular occlusive disorder of unknown etiology that can lead to devastating, permanent neurological disability if left untreated. It is characterized by progressive stenosis of the intracranial internal carotid arteries and their distal branches and the nearly simultaneous appearance of basal arterial collateral vessels that vascularize hypoperfused brain distal to the occluded vessels. Moyamoya disease may be idiopathic or may occur in association with other syndromes. Most children with moyamoya disease present with recurrent transient ischemic attacks or strokes. Although there is no definitive medical treatment, numerous direct and indirect revascularization procedures have been used to improve the compromised cerebral circulation, with outcomes varying according to procedure type. Such techniques improve the long-term outcome of patients with both idiopathic and syndrome-associated moyamoya disease. This review provides a comprehensive discussion of moyamoya disease in children, with an emphasis on the most effective surgical treatment options.

Surgical management of moyamoya disease

Moyamoya disease (MMD) is a progressive, occlusive disease of the distal internal carotid arteries associated with secondary stenosis of the circle of Willis. Symptoms include ischemic infarcts in children and hemorrhages in adults. Bypass of the stenotic vessel(s) is the primary surgical treatment modality for MMD. Superficial temporal artery-to-middle cerebral artery bypass is the most common direct bypass method. Indirect techniques rely on the approximation of vascularized tissue to the cerebral cortex to promote neoangiogenesis. This tissue may be in the form of muscle, pericranium, dura, or even omentum. This review highlights the surgical options available for the treatment of MMD.

Moyamoya disease: current concepts and future perspectives

Moyamoya disease is an uncommon cerebrovascular disease that is characterised by progressive stenosis of the terminal portion of the internal carotid artery and its main branches. The disease is associated with the development of dilated, fragile collateral vessels at the base of the brain, which are termed moyamoya vessels. The incidence of moyamoya disease is high in east Asia, and familial forms account for about 15% of patients with this disease. Moyamoya disease has several unique clinical features, which include two peaks of age distribution at 5 years and at about 40 years. Most paediatric patients have ischaemic attacks, whereas adult patients can have ischaemic attacks, intracranial bleeding, or both. Extracranial-intracranial arterial bypass, including anastomosis of the superficial temporal artery to the middle cerebral artery and indirect bypass, can help prevent further ischaemic attacks, although the beneficial effect on haemorrhagic stroke is still not clear. In this Review, we summarise the epidemiology, aetiology, clinical features, diagnosis, surgical treatment, and outcomes of moyamoya disease. Recent updates and future perspectives for moyamoya disease will also be discussed.

Effect of preoperative skull block on pediatric moyamoya disease

OBJECT

Stable hemodynamics, normocapnia, and adequate pain relief are considered important factors in the reduction of neurological complications in pediatric patients undergoing encephaloduroarteriomyosynangiosis (EDAMS) operations for the treatment of moyamoya disease. A preoperative skull block may reduce hemodynamic fluctuations and hypo- or hyperventilation due to emergence delirium or oversedation and provide adequate pain relief, thereby reducing postoperative morbidity.

METHODS

Pediatric patients (age 3-13 years) undergoing EDAMS surgery for moyamoya disease were randomly divided into a nerve block (NB) group (18 cases) or control group (21 cases). The treatment group patients received a preoperative NB (0.25% 5-8 ml bupivacaine mixed with 20-40 mg methylprednisolone) targeting the supraorbital, supratrochlear, auriculotemporal, and posterior auricular nerves. Patients in the control group did not receive NB. General anesthesia with sevoflurane was induced in both groups.

RESULTS

In the NB group, stable hemodynamic parameters were obtained with a lower sevoflurane concentration than in the control group. For delirious awakening, the odds ratio in the control group was 4.9 compared with the NB group. Pain and analgesic requirement were higher in the control patients than in the NB-treated patients during the postanesthesia care unit stay. However, the arterial CO(2) tension in the postanesthesia care unit did not differ between the 2 groups. The odds ratio in the control group for the rate of morbidity (cerebral infarction and reversible ischemic neurological deficits) during the first 24 hours following the operation was 3.2 compared with the NB group.

CONCLUSIONS

The use of skull block during EDAMS surgery provided easy hemodynamic control, calm awakening, and better pain relief and may be related to the reduced postoperative morbidity.

Long-term outcome of superficial temporal artery-middle cerebral artery bypass for patients with moyamoya disease in the US

OBJECT

The authors report the long-term results of a series of direct superficial temporal artery-middle cerebral artery (STA-MCA) bypass procedures in patients with moyamoya disease from the western US.

METHODS

All patients with moyamoya disease treated at the University of Washington from 1990 through 2004 (39 patients) were included in this study. Patients underwent pre- and postoperative evaluation of cerebral perfusion dynamics. Surgical revascularization procedures were performed in all patients with impaired cerebral blood flow (CBF) findings.

RESULTS

The mean age of patients at diagnosis was 34 years (range 10-55 years). All 39 patients had impaired CBF and/or vasomotor reserve and underwent revascularization procedures: 26 patients underwent bilateral operations, 13 unilateral (65 total procedures). An STA-MCA bypass was technically possible in 56 procedures (86.2%); saphenous vein interposition grafts were required in 3 procedures (4.6%); encephaloduroarteriosynangiosis was performed in 6 procedures (9.2%). Three patients died due to postoperative complications, yielding a procedure-related mortality rate of 4.61%, and 8 experienced non-life threatening complications (for a procedure-related rate of 12.3%). Long-term follow-up appeared to indicate a reduction in further ischemic events in surviving patients compared with the natural history. Cerebral perfusion dynamics improved postoperatively in all 36 surviving patients.

CONCLUSIONS

Moyamoya disease may differ in the US and Asia, and STA-MCA bypass procedures may prevent future ischemic events in patients with this condition.

Symptomatic hyperperfusion after superficial temporal artery-middle cerebral artery anastomosis in a child with moyamoya disease

OBJECT

Surgical revascularization for moyamoya disease prevents cerebral ischemic attacks by improving cerebral blood flow (CBF). It is undetermined, however, how rapid increase in CBF affects ischemic brain at acute stage, especially in children.

CASE REPORT

A 4-year-old girl with moyamoya disease underwent right superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. She suffered temporary left facial palsy 5 days after surgery. Postoperative N-isopropyl-p-[123I]iodoamphetamine single-photon emission computed tomography (123I-IMP-SPECT) revealed focal intense increase in CBF at the sites of anastomosis. Magnetic resonance imaging/angiography showed the apparently patent STA-MCA anastomosis as a thick high signal without ischemic changes. Her symptom improved 9 days after surgery, and single-photon emission computed tomography (SPECT) 2 months later showed normalization of CBF. Surgical revascularization completely relieved the transient ischemic attack on her left hand that was seen before surgery.

CONCLUSION

We demonstrated, for the first time, that delayed focal neurological deficit after STA-MCA anastomosis can be caused by focal hyperperfusion in childhood moyamoya disease.

Effects of intravenous anesthesia with propofol on regional cortical blood flow and intracranial pressure in surgery for moyamoya disease

BACKGROUND

The aim of this study was to compare the effects of inhalation anesthesia with sevoflurane and intravenous anesthesia with propofol on ICP and rCoBF during revascularization surgery for patients with MMD.

METHODS

Between 1999 and 2004, a total of 90 revascularization surgeries were performed on 58 patients. Among them, in 20 consecutive operations on 14 patients, continuous monitoring of ICP was performed with an ICP monitoring probe. Subsequently, in 14 consecutive operations on 9 patients (CoBF group), intraoperative monitoring of rCoBF was carried out with a laser Doppler flowmeter probe. The monitoring of ICP and rCoBF was performed for more than 20 minutes after the administration of anesthetic was changed from 1.5% to 2.5% sevoflurane to 6 mg/kg per hour of propofol. In all cases, the Paco(2) of these patients was strictly maintained between 38 and 40 mm Hg throughout the operations.

RESULTS

In both the ICP and the CoBF groups, the values of physiologic parameters obtained under inhalation anesthesia did not differ statistically from those obtained under intravenous anesthesia. The value for ICP under anesthesia with propofol was significantly lower than that under anesthesia with sevoflurane (P < .0001). The value for rCoBF in the frontal lobe under anesthesia with propofol was significantly higher than that under anesthesia with sevoflurane.

CONCLUSIONS

Intravenous anesthesia with propofol has potential to provide brain protection and preservation of rCBF in the frontal lobes in surgery for MMD. Whether choice of anesthetic agents might be important in surgery for MMD should be investigated further.

Temporary neurologic deterioration due to cerebral hyperperfusion after superficial temporal artery-middle cerebral artery anastomosis in patients with adult-onset moyamoya disease

BACKGROUND

Surgical revascularization for moyamoya disease prevents cerebral ischemic attacks by improving CBF, but little is known about the change in CBF and its effect on neurologic status during the acute stage after revascularization.

METHODS

123I-IMP-SPECT was performed 1 and 7 days after STA-MCA anastomosis on 34 sides of 27 consecutive patients with adult-onset moyamoya disease (6 men, 21 women; 22-62 years old). The follow-up period ranged from 5 to 28 months (mean, 17.6 months).

RESULTS

Thirteen patients (13 sides, 38.2%) suffered temporary neurologic deterioration due to hyperperfusion several days after surgery, which was sustained for several days (7.4 days in average). Postoperative magnetic resonance imaging/angiography showed the STA as a higher intensity signal than the preoperative finding without ischemic changes in all 13 patients. Postoperative SPECT revealed focal intense increase in CBF at the sites of anastomosis in all 13 patients. Eleven patients (32.4%) had transient focal neurologic deficit mimicking ischemic attack. Two patients (5.9%) had cerebral hyperperfusion syndrome associated with subarachnoid hemorrhage extending to the ipsilateral sylvian cistern. Symptoms were relieved by intensive blood pressure control, and no patients had permanent neurologic deficit or delayed neurologic deterioration during the follow-up period.

CONCLUSIONS

Surgical revascularization including STA-MCA anastomosis is a safe and effective treatment for moyamoya disease, although temporary neurologic deterioration due to hyperperfusion could occur at a substantial rate. Routine CBF measurement is recommended for accurate diagnosis of postoperative hyperperfusion in moyamoya disease because its treatment is contradictory to that for ischemia.

Acute carotid arterial occlusion after burr hole surgery for chronic subdural haematoma in moyamoya disease

Ischaemic strokes and neurological deterioration have been described after revascularisation surgery in patients with moyamoya disease, but accelerated acute occlusion of the internal carotid artery after burr hole surgery has not been reported in this setting. A 66-year-old woman with known moyamoya disease who presented with right motor weakness underwent burr hole surgery for a bilateral chronic subdural haematoma. Postoperatively, the patient had a crescendo transient ischaemic attack and then deteriorated. Angiography showed complete occlusion of the left internal carotid artery. Burr hole surgery may cause postoperative acute occlusion of a preexisting stenotic artery in patients with moyamoya disease.

[Spinal anaesthesia and Moya Moya disease]

Moya Moya is a rare disease of uncertain origin, characterised by stenosis of one or both of the internal carotid arteries and responsible of several neurological signs. We present the case of a boy with Moya Moya disease who was scheduled for an epiphisiodesis of the lateral malleola and had a spinal anaesthesia with hyperbaric bupivacaine 0.5% 10 mg without any perioperative complications. Any anaesthetic method could be used, provided special attention is given to avoid changes of capnea and blood pressure to preserve cerebral blood flow and palliate to cerebral flow steal.

Frontal lobe infarction due to hemodynamic change after surgical revascularization in moyamoya disease--two case reports

A 60-year-old female and a 40-year-old male underwent surgical revascularization for moyamoya disease and suffered small infarction in the ipsilateral frontal lobe 3 or 4 days postoperatively. Neuroimaging suggested that the bypass flow had caused rapid progression of occlusive changes in the carotid forks, a diminishing of moyamoya vessels, and flow reduction in the anterior cerebral artery ipsilateral to surgery, leading to critical ischemia in the frontal lobe. Surgical revascularization improves the outcome of patients with moyamoya disease, but postoperative management such as hydration is important to avoid ischemic complications due to frontal lobe infarction.

Direct and combined revascularization in pediatric moyamoya disease

OBJECTIVE

Surgical revascularization of moyamoya disease can improve neurological outcomes, compared with the natural history of the disease or the results of medical treatment. Controversy exists regarding whether direct or indirect revascularization yields better outcomes. This study involves a single-center experience with direct anastomosis and is the first North American series using direct revascularization for pediatric patients with moyamoya disease.

METHODS

Twelve patients (age range, 5-17 yr; mean age, 10.2 yr) underwent direct revascularization of 21 hemispheres. Two patients had experienced failure of previous indirect revascularization procedures, with continued clinical deterioration. Superficial temporal artery-middle cerebral artery anastomosis was performed in 19 hemispheres (with concurrent encephaloduroarteriosynangiosis in 6). Middle meningeal artery-middle cerebral artery anastomosis and omental transposition were each performed in one hemisphere. Follow-up periods ranged from 12 to 65 months (mean, 35 mo), and monitoring included neurological examinations, angiography, magnetic resonance imaging, and cerebral blood flow studies.

RESULTS

The neurological conditions of all patients were stable or improved after surgery. None of the patients developed new strokes, and no new ischemic lesions were seen in magnetic resonance imaging scans. All grafts evaluated by follow-up angiography were patent. Postoperative cerebral blood flow studies showed significantly improved blood flow (54.4 versus 42.5 ml/100 g/min; P = 0.017, n = 4) and hemodynamic reserve (70.3 versus 43.9 ml/100 g/min; P = 0.009, n = 4), compared with preoperative studies.

CONCLUSION

Surgical revascularization by direct anastomosis in pediatric patients is technically feasible, is well tolerated, and can improve the progressive natural history, the angiographic appearance, and the cerebral blood flow abnormalities associated with the disease. Direct revascularization has the advantage of providing immediate and high-flow revascularization and is particularly useful for patients who have experienced failure of previous indirect revascularization procedures.