Intellectual functions and regional cerebral haemodynamics after extensive omental transplantation spread over both frontal lobes in childhood moyamoya disease

Post-Surgical Cognitive Outcomes of Moyamoya Disease: A Systematic Review

BACKGROUND

Moyamoya disease (MMD) is an occlusive arteriopathy leading to stroke. Progressive if left untreated, revascularization surgery has become the mainstay of treatment. Although clinical and radiographic outcomes of MMD after intervention are well-characterized, cognitive outcomes in pediatric patients remain unclear. We aimed to examine postoperative cognitive outcomes in children with MMD, examine factors associated with cognitive changes after intervention, and define the effect of revascularization surgery on cognitive outcomes.

METHODS

A systematic review was conducted following PRISMA guidelines searching PubMed, Embase, and Scopus databases. Articles met inclusion criteria if they studied pediatric patients undergoing revascularization surgery for MMD and examined cognitive outcomes either qualitatively or quantitatively. All data extracted from included articles was examined descriptively.

RESULTS

Of 1091 resultant articles, 12 articles containing 446 patients were included. Surgery was associated with maintained or improved full scale intellectual quotient (IQ), performance IQ, perceptual IQ, memory quotient and verbal memory. However, 70% of patients had impaired cognitive function, with associated poor school performance. Improvements in cognition were associated with increased cerebral blood flow, particularly to the middle cerebral artery, due to the development of collaterals. Female sex, shorter duration from symptom onset to surgery, and surgery after age 7 were predictive of cognitive improvement. Completed ischemic stroke prior to surgery was associated with poorer cognitive outcomes.

CONCLUSIONS

Although children with MMD have improved cognitive outcomes following revascularization overall, a distinct subset experience cognitive impairment. Consideration of patient-specific and treatment-related factors is important to enable proper risk stratification and inform management approaches.

Characterization of Neuropsychological Outcomes in a Cohort of Pediatric Patients with Moyamoya Arteriopathy

INTRODUCTION

Moyamoya arteriopathy is a severe, progressive cerebral arteriopathy that places affected children at high risk for stroke. Moyamoya has been associated with a range of neuropsychological deficits in adults, but data on many cognitive domains remain limited in the pediatric population and little is known about the neuropsychological profile of children with syndromic moyamoya.

METHODS

This is a single-center, retrospective cohort study of children with moyamoya arteriopathy followed at our center who underwent neuropsychological testing between 2003 and 2021. Test scores were extracted from neuropsychological reports. Medical records were reviewed with attention to individual neuropsychological test results, medical comorbidities, presence of infarct(s) on neuroimaging, and history of clinical ischemic stroke.

RESULTS

Of the 83 children with moyamoya followed at our center between 2003 and 2021, 13 had completed neuropsychological testing across multiple cognitive domains. Compared to age-based normative data, children in this sample had lower scores in overall intelligence (p = 0.003), global executive functioning (p = 0.005), and overall adaptive functioning (p = 0.015). There was no significant difference in overall intelligence between children with (n = 6) versus without (n = 7) a history of clinical stroke (p = 0.368), though children with any radiographic infarct scored lower in this domain (p = 0.032).

CONCLUSION

In our cohort, children with moyamoya demonstrated impaired intelligence and executive functioning, even in the absence of clinical stroke. Neuropsychological evaluation should be considered standard of care for all children with moyamoya, even those without a history of clinical stroke.

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.

Fronto-Parietal and White Matter Haemodynamics Predict Cognitive Outcome in Children with Moyamoya Independent of Stroke

Moyamoya disease is a major arteriopathy characterised by progressive steno-occlusion of the arteries of the circle of Willis. Studies in adults with moyamoya suggest an association between abnormal fronto-parietal and white matter regional haemodynamics and cognitive impairments, even in the absence of focal infarction. However, these associations have not been investigated in children with moyamoya. We examined the relationship between regional haemodynamics and ratings of intellectual ability and executive function, using hypercapnic challenge blood oxygen level-dependent magnetic resonance imaging of cerebrovascular reactivity in a consecutive cohort of children with confirmed moyamoya. Thirty children were included in the final analysis (mean age: 12.55 ± 3.03 years, 17 females, 15 idiopathic moyamoya and 15 syndromic moyamoya). Frontal haemodynamics were abnormal in all regardless of stroke history and comorbidity, but occipital lobe haemodynamics were also abnormal in children with syndromic moyamoya. Executive function deficits were noted in both idiopathic and syndromic moyamoya, whereas intellectual ability was impaired in syndromic moyamoya, even in the absence of stroke. Analysis of the relative effect of regional abnormal haemodynamics on cognitive outcomes demonstrated that executive dysfunction was predominantly explained by right parietal and white matter haemodynamics independent of stroke and comorbidity, while posterior circulation haemodynamics predicted intellectual ability. These results suggest that parietal and posterior haemodynamics play a compensatory role in overcoming frontal vulnerability and cognitive impairment.

Characterizing the neurocognitive profiles of children with moyamoya disease using the Das Naglieri cognitive assessment system

Although cognitive impairment is well-documented in children with moyamoya disease (MMD), selective decline in specific neurocognitive domains remains controversial. The purpose of this study was to characterize the neurocognitive profile of children with MMD using the Das Naglieri Cognitive Assessment System (CAS) and the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV). We analyzed the neurocognitive data of 30 children (median age, 7 years) with MMD who were assessed with the CAS and the WISC-IV before surgery. We focused on the comparison of standard scores and intraindividual differences across domains. The CAS scores significantly varied across four measures (standard scores, p < 0.001; intraindividual differences, p < 0.001). Post-hoc analyses revealed that the standard scores and intraindividual differences for successive processing were significantly lower than those for planning and attention. The WISC-IV scores did not significantly vary among the four measures, although the working memory index was the lowest among the four measures. The within-individual weakness in successive processing, a form of working memory function, may be a distinct characteristic of children with MMD. The CAS may be more sensitive than the WISC-IV for detecting this selective neurocognitive weakness in children with MMD.

Surgical revascularization of frontal areas in pediatric Moyamoya vasculopathy: a systematic review

INTRODUCTION

The aim of this study is to systematically review the literature on surgical revascularization techniques for flow-augmentation of the frontal areas and/or anterior cerebral artery (ACA) territory in children with Moyamoya vasculopathy (MMV), to elucidate the current surgical practice and describe the outcome associated to the different techniques.

EVIDENCE ACQUISITION

The systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. MEDLINE, Web of Science and EMBASE were searched up to April 2020. Published techniques were systematically analyzed according to level of evidence, revascularization technique, opening of the interhemispheric fissure (IF), uni- or bilateral revascularization, clinical, neurocognitive, angiographic, perfusion and hemodynamic outcome.

EVIDENCE SYNTHESIS

Twenty-five studies were enrolled, including 829 patients: among these, 13 patients underwent direct revascularization of ACA territories, 570 indirect revascularization and 246 patients combined revascularization. One study reached a level of evidence II (grade of recommendation B), 8 studies were level III (grade B) and 16 studies were level IV (grade C). The surgical techniques proposed in the enrolled papers were systematically described.

CONCLUSIONS

Combined techniques (grade of recommendation B) and indirect techniques (grade of recommendation C) are considered effective for revascularizing the frontal areas and/or anterior cerebral artery (ACA) territory in children with MMV. While performing the revascularization, surgical risks can be reduced by avoiding the exposure of the superior sagittal sinus and opening of IF (recommendation grade C). There is not sufficient evidence to define which type of surgical technique should be preferred. Future studies are needed for a longitudinal assessment of comparable outcomes and to determine which revascularization technique for the frontal areas and/or ACA territory is optimal for this highly specific pediatric population.

Postoperative change of neuropsychological function after indirect revascularization in childhood moyamoya disease: a correlation with cerebral perfusion study

PURPOSE

The relationships between postoperative functional improvement in various cognitive domains and regional hemodynamic change have not been sufficiently studied in childhood moyamoya disease (MMD). The present study aimed to examine the cognitive benefit of indirect revascularization, the underlying biological mechanism, and factors affecting surgical outcome in childhood MMD.

METHODS

Twenty-three patients with MMD aged under 20 years received neuropsychological examinations before and after indirect revascularization surgery, evaluating intellectual function, verbal and visual memory, and executive function. Among them, 13 patients had magnetic resonance perfusion (MRP) studies, in which regional cerebral perfusion was rated.

RESULTS

Postoperative improvement was observed in verbal memory performances (p = 0.02-0.03) and in cerebral perfusion at all 26 cerebral hemispheres (p = 0.003-0.005), especially in the middle cerebral artery (MCA) territories (p = 0.001-0.003). Hemodynamic improvement in the left MCA territories was significantly correlated with improvement of both verbal new learning (p = 0.01) and intellectual function (p = 0.004). Postoperative cognitive improvement of immediate recall and verbal intellectual function was associated with female sex (r = - 0.42) and symptom duration (p = - 0.03), respectively. Hemodynamic improvement in the MCA territories was related to longer follow-up intervals (p = 0.02).

CONCLUSION

The findings revealed that the selective postoperative cognitive improvement was associated with increased regional perfusion in the MCA territories, and indicate the importance of early intervention and the potential of indirect revascularization regarding long-term outcome.

Modified encephalo-duro-periosteal-synangiosis (EDPS) for the revascularization of anterior cerebral artery territory in moyamoya disease: A single-center experience

OBJECTIVES

Anterior cerebral artery (ACA) territory, a crucial area of intellectual development in children, is frequently involved in the progress of moyamoya disease (MMD). However, revascularization surgeries for this area are not as established as surgeries for middle cerebral artery (MCA) territory. This study aimed to describe our experience and study the effect of revascularizing ACA territory with periocranium and dural leaflets, which is referred to as 'encephalo-duro-periosteal-synangiosis (EDPS)'.

PATIENTS AND METHOD

Fourteen hemispheres of 9 MMD patients who had undergone EDPS from November 2015 till July 2017 in our hospital were retrospectively included. Clinical characteristics and procedure-related information were recorded. Cerebral perfusion was evaluated by computed tomography perfusion (CTP). Absolute and relative (r) CTP parameters of ROIs in ACA territory at the level of centrum semiovale and middle basal ganglia were calculated. Preoperative and postoperative parameters were compared.

RESULTS

All EDPS procedures were technically successful with no postoperative complications. The mean operating time was 75.00 ± 22.53 min per hemisphere. Postoperative absolute cerebral blood flow (CBF), rCBF were significantly increased and absolute time to peak (TTP), rTTP, absolute mean transit time (MTT) were significantly reduced in ACA territory at centrum semiovale level (P = 0.002, 0.045, 0.007, 0.005 and 0.039 respectively). Improved outcomes were achieved in five patients, stabilization in three and one patient had deterioration out of intracerebral hemorrhage during follow-up.

CONCLUSION

EDPS is a simple but effective technique to revascularize ACA territory for MMD. EDPS significantly improved cerebral blood perfusion of frontal lobe in the majority of patients without increasing procedure-related risks.

Childhood Moyamoya: Looking Back to the Future

Moyamoya is a chronic, progressive steno-occlusive arteriopathy that typically affects the anterior circulation arteries of the circle of Willis. A network of deep thalamoperforating and lenticulostriate collaterals develop to by-pass the occlusion giving rise to the characteristic angiographic "puff of smoke" appearance. Moyamoya confers a lifelong risk of stroke and neurological demise, with peak age of presentation in childhood ranging between five and 10 years. Moyamoya disease refers to patients who do not have a comorbid condition, whereas moyamoya syndrome refers to patients in whom moyamoya occurs in association with an acquired or inherited disorder such as sickle cell disease, neurofibromatosis type-1 or trisomy 21. The incidence of moyamoya disease and moyamoya syndrome demonstrates geographic and ethnic variation, with a predominance of moyamoya disease in East-Asian populations. Antiplatelet therapy and surgical revascularization procedures are the mainstay of management, as there are no available treatments to slow the progression of the arteriopathy. Future research is required to address the major gaps that remain in our understanding of the pathologic basis, optimal timing for surgery, and determinants of outcome in this high-stroke risk condition of childhood.

Cognitive Functions in Children and Adults with Moyamoya Vasculopathy: A Systematic Review and Meta-Analysis

Background and Purpose

Patients with moyamoya vasculopathy (MMV) may experience cognitive impairment, but its reported frequency, severity, and nature vary. In a systematic review and metaanalysis, we aimed to assess the presence, severity, and nature of cognitive impairments in children and adults with MMV.

Methods

We followed the MOOSE guidelines for meta-analysis and systematic reviews of observational studies. We searched Ovid Medline and Embase for studies published between January 1, 1969 and October 4, 2016. Independent reviewers extracted data for mean intelligence quotient (IQ) and standardized z-scores for cognitive tests, and determined percentages of children and adults with cognitive deficits, before and after conservative or surgical treatment. We explored associations between summary measures of study characteristics and cognitive impairments by linear regression analysis.

Results

We included 17 studies (11 studies reporting on 281 children, six on 153 adults). In children, the median percentage with impaired cognition was 30% (range, 13% to 67%); median IQ was 98 (range, 71 to 107). Median z-score was –0.39 for memory, and –0.43 for processing speed. In adults, the median percentage with impaired cognition was 31% (range, 0% to 69%); median IQ was 95 (range, 94 to 99). Median z-scores of cognitive domains were between –0.9 and –0.4, with multiple domains being affected. We could not identify determinants of cognitive impairment.

Conclusions

A large proportion of children and adults with MMV have cognitive impairment, with modest to large deficits across various cognitive domains. Further studies should investigate determinants of cognitive deficits and deterioration, and the influence of revascularization treatment on cognitive functioning.

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.

Successful Laparoscopic Harvesting of Omental Pedicle Flap for Salvage Cerebral Revascularization in 2 Adults With Moyamoya Disease: Technique and Lessons Learned

Moyamoya is an idiopathic and progressive disease that leads to occlusion of intracranial arteries. When other methods of revascularization fail, omentum can be used as an indirect bypass to improve cerebral perfusion. Laparoscopic mobilization of a pedicled omental flap with subcutaneous tunneling to the brain has been described in small case series in children. We report our techniques and outcomes in 2 adults with Moyamoya to undergo such a procedure. An omental flap based on the right gastroepiploic artery was created and intraoperative fluorescence imaging using indocyanine green was used to assess the viability of the flap and to guide lengthening of the pedicle. The flap was tunneled subcutaneously using skip incisions. There were no intraoperative complications and no postoperative complications related to the omental flap. Follow-up evaluation demonstrates viable omental flaps and improved cerebral vascularization. This technique is feasible in adults who require salvage cerebral revascularization for Moyamoya disease.

Cerebrovascular Reactivity and Intellectual Outcome in Childhood Stroke With Transient Cerebral Arteriopathy

BACKGROUND

Hypercapnic-challenge blood oxygen level-dependent magnetic resonance imaging cerebrovascular reactivity (CVR), measures the regional perfusion response to altered carbon dioxide. CVR correlates with the tissue-level microvascular dysfunction and ischemic risk. Among children with arterial ischemic stroke, transient cerebral arteriopathy (TCA) is a frequent, nonprogressive unilateral intracranial arteriopathy, which typically results in basal ganglia infarction and chronic cerebral artery stenosis. Therefore TCA provides a model for studying the consequences of chronic nonprogressive stenosis using CVR and intellectual outcome. We hypothesized that children with TCA and chronic nonprogressive intracranial artery stenosis have impaired CVR distal to the stenosis and associated cognitive impairment.

METHODS

We studied children with a prior diagnosis of TCA as defined by infarction limited to the basal ganglia, internal capsule, or both; and significant (greater than 50% diameter) residual stenosis of the supraclinoid internal carotid artery, its proximal branches or both. All children had CVR, intellectual function, and infarct volumes quantified.

RESULTS

We performed CVR studies in five children at mean 8.96 years (3.33 to 14.58 years) poststroke. Impaired CVR was limited to the infarct zone and adjacent white matter in most children. Intellectual function was broadly average in all but one subject.

CONCLUSIONS

In children with typical TCA, ipsilateral cortical CVR and intellectual function seem to be preserved despite persistent arterial stenosis in the majority. These findings suggest that chronic revascularization strategies in these children may not be indicated and require further exploration in a larger cohort of children.

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.

Research Progress of Moyamoya Disease in Children

During the onset of Moyamoya disease (MMD), progressive occlusion occurs at the end of the intracranial internal carotid artery, and compensatory net-like abnormal vessels develop in the skull base, generating the corresponding clinical symptoms. MMD can affect both children and adults, but MMD in pediatric patients exhibits distinct clinical features, and the treatment prognoses are different from adult patients. Children are the group at highest risk for MMD. In children, the disease mainly manifests as ischemia, while bleeding is the primary symptom in adults. The pathogenesis of MMD in children is still unknown, and some factors are distinct from those in adults. MMD in children could result in progressive, irreversible nerve functional impairment, and an earlier the onset corresponds to a worse prognosis. Therefore, active treatment at an early stage is highly recommended. The treatment methods for MMD in children mainly include indirect and direct surgeries. Indirect surgeries mainly include multiple burr-hole surgery (MBHS), encephalomyosynangiosis (EMS), and encephaloduroarteriosynangiosis (EDAS); direct surgeries mainly include intra- and extracranial vascular reconstructions that primarily consist of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. Indirect surgery, as a treatment for MMD in children, has shown a certain level of efficacy. However, a standard treatment approach should combine both indirect and direct procedures. Compared to MMD in adults, the treatment and prognosis of MMD in children has higher clinical significance. If the treatment is adequate, a satisfactory outcome is often achieved.

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.

Differential clinical outcomes following encephaloduroarteriosynangiosis in pediatric moyamoya disease presenting with epilepsy or ischemia

PURPOSE

The purpose of this study was to compare clinical outcomes and surgical results after encephaloduroarteriosynangiosis (EDAS) in pediatric patients with Moyamoya disease that manifested as either ischemia or epileptic seizures.

METHODS

We treated 23 children who underwent EDAS; we divided the patients into either ischemic or epileptic groups according to the individuals' clinical presentation. Group Ia included those who mainly presented with cerebral ischemia in the form of preoperative transient ischemic attacks (TIA), while Group Ib presented with ischemia in the form of irreversible neurologic deficits or proven cerebral infarcts. Group II included those who presented with epileptic seizures rather than cerebral ischemia. We compared the clinical outcomes and surgical results following EDAS in the three groups.

RESULTS

We grouped the patients into three groups according to their main preoperative clinical symptoms (Group Ia n = 10, Group Ib n = 6, and Group II n = 7). Group II, the epileptic manifestation group, tended to show more favorable clinical outcomes compared to the ischemic manifestation group, especially the severe ischemic group. However, there were no significant differences in postoperative neuroimaging and hemodynamic assessments between the groups.

CONCLUSIONS

EDAS is a safe and effective surgical technique that prevents epileptic seizures and shows more favorable clinical outcomes when used in patients with Moyamoya disease presenting with epileptic seizures compared to cerebral ischemia.

Less invasive pedicled omental-cranial transposition in pediatric patients with moyamoya disease and failed prior revascularization

BACKGROUND

Patients with moyamoya disease and progressive neurological deterioration despite previous revascularization pose a major treatment challenge. Many have exhausted typical sources for bypass or have ischemia in areas that are difficult to reach with an indirect pedicled flap. Omental-cranial transposition has been an effective, but sparingly used technique because of its associated morbidity.

OBJECTIVE

We have refined a laparoscopic method of harvesting an omental flap that preserves its gastroepiploic arterial supply.

METHODS

The pedicled omentum can be lengthened as needed by dividing it between the vascular arcades. It is transposed to the brain via skip incisions. The flap can be trimmed or stretched to cover ischemic areas of the brain. The cranial exposure is performed in parallel with pediatric surgeons. We performed this technique in 3 pediatric patients with moyamoya disease (aged 5-12 years) with previous superficial temporal artery to middle cerebral artery bypasses and progressive ischemic symptoms. In 1 patient, we transposed omentum to both hemispheres.

RESULTS

Blood loss ranged from 75 to 250 mL. After surgery, patients immediately tolerated a diet and were discharged in 3 to 5 days. The ischemic symptoms of all 3 children resolved within 3 months postoperatively. Magnetic resonance imaging at 1 year showed improved perfusion and no new infarcts. Angiography showed excellent revascularization of targeted areas and patency of the donor gastroepiploic artery.

CONCLUSION

Laparoscopic omental harvest for cranial-omental transposition can be performed efficiently and safely. Patients with moyamoya disease appear to tolerate this technique much better than laparotomy. With this method, we can achieve excellent angiographic revascularization and resolution of ischemic symptoms.

Cognitive function of patients with adult moyamoya disease

BACKGROUND

Neurocognitive impairment is one of several unsolved social issues faced by patients with moyamoya disease. Although efforts have been made to investigate cognitive function using neuropsychologic tasks, generalizability has been limited. Here, in a preliminary study, we used structured neuropsychologic tasks to establish a standardized neuropsychologic assessment for adult moyamoya patients with and without difficulty in social independence.

METHODS

Ten patients with neuroradiologically confirmed adult moyamoya disease (3 male, 7 female) participated. Half of all subjects did not have difficulty with social independence (group 1) and the others had (group 2). Group differences were evaluated after basic cognitive abilities and frontal lobe function were tested.

RESULTS

Although the mean age of group 1 was substantially higher than that of group 2, disease duration did not differ significantly between groups. Means scores for intelligence functions including all subtests for basic cognitive abilities were higher in group 1 compared with group 2. Scores from only 2 frontal lobe evaluation tasks (Trail Making Test B and Theory of Mind) were significantly different between groups.

CONCLUSIONS

This preliminary study provides a profile of neurocognitive dysfunction in adult patients with moyamoya disease using structured neuropsychologic tasks. A broad range of cognitive functions was disrupted particularly in the patients who had difficulty with social independence. To obtain stronger evidence regarding neurocognitive dysfunction in patients with moyamoya disease, a multicenter prospective study is essential.

Combined Bypass Technique for Contemporary Revascularization of Unilateral MCA and Bilateral Frontal Territories in Moyamoya Vasculopathy

Moyamoya vasculopathy (MMV) leads to chronic hypoperfusion predominantly in the middle cerebral artery (MCA) and anterior cerebral artery (ACA) territories. Most revascularization techniques focus on revascularization of the MCA territory. Augmentation of blood flow in the frontal area is important for neurocognition and lower extremity function. In this article we describe a new combined (direct and indirect) one-stage bypass technique consisting of a superficial temporal artery to middle cerebral artery (STA-MCA) bypass with encephalo-duro-synangiosis (EDS) for unilateral MCA revascularization, along with an encephalo-duro-periosteal-synangiosis (EDPS) for bifrontal blood flow augmentation. The strength of this technique is the revascularization of three vascular territories during a single surgical intervention: the MCA unilaterally; and the frontal territories bilaterally. Bifrontal EDPS may also be considered as a supplementary independent procedure for patients who previously underwent revascularization treatment in the MCA territory, but develop symptoms due to frontal hypoperfusion.

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.

Hemodynamic improvement of anterior cerebral artery territory perfusion induced by bifrontal encephalo(periosteal) synangiosis in pediatric patients with moyamoya disease: a study with brain perfusion SPECT

OBJECTIVE

The reinforcement of the anterior cerebral artery (ACA) territory perfusion is important for the future intellectual functioning of pediatric moyamoya disease (MMD) patients. To evaluate the hemodynamic improvement of the ACA territory, bifrontal encephalogaleo-(periosteal)synangiosis [EG(P)S] combined with encephaloduroarteriosynangiosis (EDAS) was compared with EDAS alone in pediatric MMD patients using brain perfusion SPECT.

METHODS

Among 36 patients (M:F = 16:20; mean age, 9.5 ± 3.0 years) who were surgically treated for MMD, EDAS was performed in 17 patients, and EDAS with bifrontal EG(P)S in 19 patients. Hemodynamic parameters consisting of basal cerebral perfusion, acetazolamide-challenge stress perfusion, and cerebrovascular reserve index were estimated using brain perfusion SPECT and probabilistic perfusion maps for the ACA and middle cerebral artery (MCA) territories. Cerebral angiography was performed to confirm revascularization.

RESULTS

Both the EDAS only (p = 0.04) and EDAS with EG(P)S group (p < 0.001) had significant improvements in cerebrovascular reserve of the ipsilateral MCA territory. The EDAS with EG(P)S group had significant improvements, not only in basal perfusion of the ipsilateral ACA territory (p = 0.03) but also in the cerebrovascular reserve of the bilateral ACA territories (p < 0.01). In parallel with the hemodynamic changes assessed by brain perfusion SPECT, neovascularization was noted in the ipsilateral MCA territory in both the EDAS only and EDAS with EG(P)S group, and in the ipsilateral ACA territory in the EDAS with EG(P)S group on the postoperative cerebral angiography.

CONCLUSIONS

EDAS with bifrontal EG(P)S induces significant improvements in the ACA and MCA territories, while EDAS generates significant improvements in the MCA territory only.

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.

Modified encephaloduroarteriosynangiosis with bifrontal encephalogaleoperiosteal synangiosis for the treatment of pediatric moyamoya disease. Technical note

The authors describe a modified technique of encephaloduroarteriosynangiosis (EDAS) with bifrontal encephalogaleoperiosteal synangiosis (EGPS) and present the preliminary results of the procedure. Between January 2004 and June 2005 the authors performed modified EDAS with bifrontal EGPS in 17 patients with moyamoya disease. Surgical results were evaluated in terms of clinical outcomes, changes visible on neuroimages, extent of revascularization noted on angiograms, and hemodynamic changes demonstrated on single-photon emission computed tomography (SPECT) scans. The follow-up period ranged from 6 to 21 months (mean 11.5 months). The overall clinical outcomes were excellent or good in 15 patients (88.2%) and poor in two (11.8%). The overall morbidity rate was 5.9% (one of 17 patients). Based on changes in the anterior cerebral artery (ACA) and middle cerebral artery (MCA) territories after surgery, as shown on SPECT scans following administration of acetazolamide, 14 patients (82.4%) exhibited an improved vascular reserve capacity in both the ACA and MCA territories. It is the authors' opinion that wide covering of the cortex is necessary for sufficient revascularization. In the present study they demonstrate that modified EDAS with bifrontal EGPS is a safe and efficient surgical approach that covers not only the MCA territory but also the ACA territory.

Surgical management of moyamoya syndrome

Moyamoya syndrome, a vasculopathy characterized by chronic progressive stenosis at the apices of the intracranial internal carotid arteries, is an increasingly recognized entity which is associated with cerebral ischemia. Diagnosis is made on the basis of clinical and radiographic findings, including a characteristic stenosis of the internal carotid arteries in conjunction with abundant collateral vessel development. Adult moyamoya patients often present with hemorrhage, leading to rapid diagnosis. In contrast, children usually present with transient ischemic attacks or strokes, which may prove more difficult to diagnose because of patient's inadequate verbal and other skills, leading to delayed recognition of the underlying moyamoya. The progression of disease can be slow, with rare, intermittent events, or it can be fulminant, with rapid neurologic decline. However, regardless of the course, it is apparent that moyamoya syndrome, both in terms of arteriopathy and clinical symptoms, inevitably progresses in untreated patients. Surgery is generally recommended for the treatment of patients with recurrent or progressive cerebral ischemic events and associated reduced cerebral perfusion reserve. Many different operative techniques have been described, all with the main goal of preventing further ischemic injury by increasing collateral blood flow to hypoperfused areas of the cortex, using the external carotid circulation as a donor supply. This article discusses the various treatment approaches, with an emphasis on the use of pial synangiosis, a method of indirect revascularization. The use of pial synangiosis is a safe, effective, and durable method of cerebral revascularization in moyamoya syndrome and should be considered as a primary treatment for moyamoya, especially in the pediatric population.

Prediction of the clinical outcome of pediatric moyamoya disease with postoperative basal/acetazolamide stress brain perfusion SPECT after revascularization surgery

BACKGROUND AND PURPOSE

We evaluated whether basal/acetazolamide stress brain perfusion SPECT performed after revascularization surgery can predict the further clinical outcome of patients with pediatric moyamoya disease.

METHODS

A total of 77 (31 males, 46 females, age 6.6+/-3.2 years) patients with postoperative pediatric moyamoya disease who underwent basal/acetazolamide stress brain perfusion SPECT 6 to 12 months after revascularization surgery and who were followed-up >12 months after SPECT were included. Mean follow-up period after SPECT was 36+/-19 months. Sixty-two patients underwent bilateral ribbon encephaloduroarteriosynangiosis (EDAS), 14 bilateral EDAS, and 1 unilateral EDAS. Ordinal logistic regression analysis using 5 independent variables (infarction on preoperative MRI, age at the first operation, highest Suzuki stage on cerebral angiography, and regional cerebrovascular reserve on postoperative SPECT) against postoperative clinical outcomes was performed.

RESULTS

Fifty-one patients had preserved reserve on postoperative SPECT and their clinical outcomes were excellent (30), good (15), fair (4), and poor (2); 26 patients had decreased reserve (excellent, 1; good, 7; fair, 14; poor, 4). On ordinal logistic regression analysis, age at the first operation (P=0.033) and reserve on postoperative SPECT (P<0.001) were statistically significant.

CONCLUSIONS

Basal/acetazolamide stress brain perfusion SPECT performed at 6 to 12 months after the indirect bypass operation could predict the further clinical outcome of pediatric patients with moyamoya disease. Patients with decreased cerebrovascular reserve will have remaining neurological deficit and ischemic attacks on follow-up.

Moyamoya Disease among Young Patients: Its Aggressive Clinical Course and the Role of Active Surgical Treatment

OBJECTIVE

The prognosis for moyamoya disease (MMD) among young patients is known to be worse than that among older patients. The aim of this study was to investigate the clinical features and treatment outcomes of young patients with MMD.

METHODS

A total of 204 patients with MMD who underwent encephaloduroarteriosynangiosis, with or without bifrontal encephalogaleosynangiosis, were categorized into three groups according to their ages at the time of surgery, i.e., Group A (n = 23, <3 yr of age), Group B (n = 50, 3-6 yr of age), and Group C (n = 131, >6 yr of age). For each group, patterns of presentation and the occurrence of subsequent preoperative or surgery-related infarctions were assessed. Clinical outcomes and postoperative hemodynamic status were analyzed.

RESULTS

At initial presentation, infarctions were significantly more frequent in Group A (87%) and Group B (58%) than in Group C (46%). Subsequent preoperative infarctions occurred significantly more frequently in Group A (39%) than in Group B (6%) or Group C (0.8%). The median interval between the onset of symptoms and a subsequent preoperative infarction was 3 months (range, 1-14 mo). No significant difference in the rates of surgery-related infarctions among the three groups was observed. The rate of favorable clinical outcomes was significantly lower in Group A (58%) than in Group B (84%) or Group C (86%), although the rates of postoperative hemodynamic improvements were similar among the groups. The poor clinical outcomes for Group A were caused mainly by preoperative infarctions.

CONCLUSION

Young-age MMD demonstrates rapid disease progression and results in poor clinical outcomes. These findings indicate the necessity of early surgery for young patients with MMD; however, the actual benefits should be verified with additional controlled studies, with long-term follow-up monitoring.

Surgical approaches to vascular anomalies of the child's brain

The population of pediatric patients with cerebrovascular disease presents a unique set of challenges to the neurosurgeon. The wide scope of pathology, including arteriovenous malformations, cavernous malformations and moyamoya disease, coupled with marked advances in diagnosis and treatment of these conditions over the past several years has resulted in a proliferation of the literature related to this subject. The present review provides an overview of current methods of surgical treatment for pediatric cerebrovascular diseases, focusing on indications and use of recent refinements of pre-existing surgical approaches, and newly evolved operative techniques developed to treat these entities.

Omental free flap reconstruction in complex head and neck deformities

BACKGROUND

Microvascular free flaps continue to revolutionize coverage options in head and neck reconstruction. This article reviews our 25-year experience with omental free tissue transfers.

METHODS

All patients who underwent free omental transfer to the head and neck region were reviewed.

RESULTS

Fifty-five patients were included with omental transfers to the scalp (25%), craniofacial (62%), and neck (13%) region. Indications were tumor resections, burn wound, hemifacial atrophy, trauma, and moyamoya disease. Average follow-up was 3.1 years (range, 2 months-13 years). Donor site morbidities included abdominal wound infection, gastric outlet obstruction, and postoperative bleeding. Recipient site morbidities included partial flap loss in four patients (7%) total flap loss in two patients (3.6%), and three hematomas.

CONCLUSIONS

The omental free flap has acceptable abdominal morbidity and provides sufficient soft tissue coverage with a 96.4% survival. The thickness \and versatility of omentum provide sufficient contour molding for craniofacial reconstruction. It is an attractive alternative for reconstruction of large scalp defects and badly irradiated tissue.

Combined encephaloduroarteriosynangiosis and bifrontal encephalogaleo(periosteal)synangiosis in pediatric moyamoya disease

OBJECTIVE

We compared the surgical results of simple encephaloduroarteriosynangiosis (EDAS) and EDAS with bifrontal encephalogaleo(periosteal)synangiosis for the treatment of pediatric moyamoya disease.

METHODS

Data for 159 children (up to 15 yr of age, 76 boys and 83 girls) who underwent indirect revascularization procedures for the treatment of moyamoya disease between 1987 and 1998 were retrospectively reviewed. Group A patients underwent simple EDAS (n = 67). Group B patients underwent EDAS with bifrontal encephalogaleo(periosteal)synangiosis (n = 92). The surgical results for each group were compared, in terms of clinical outcomes, neuroimaging changes, extent of revascularization evident on angiograms, and hemodynamic changes evident on single-photon emission computed tomographic scans. The average follow-up periods were 45 months for Group A and 22 months for Group B.

RESULTS

The overall clinical outcomes and neuroimaging changes tended to be better for Group B. In terms of single-photon emission computed tomographic changes of the whole brain after surgery, Group B patients exhibited more favorable outcomes than did Group A patients (62 versus 36%, P = 0.003). The surgical results for the anterior cerebral artery territory were significantly better for Group B than for Group A, with respect to outcomes of anterior cerebral artery symptoms (81 versus 40%, P = 0.015), revascularization on angiograms (79 versus 16%, P < 0.001), and hemodynamic changes on single-photon emission computed tomographic scans (70 versus 52%, P = 0.002). The incidences of postoperative infarctions were not significantly different between the two groups.

CONCLUSION

EDAS with bifrontal encephalogaleo(periosteal)synangiosis is a more effective surgical modality for the treatment of pediatric moyamoya disease, compared with simple EDAS, because it covers both the middle cerebral artery and anterior cerebral artery territories of the brain.

The neurochemical basis for the applications of the greater omentum in neurosurgery

The omentum has been utilized in neurosurgery for over 30 years. However, the anatomical and physiological bases for its applications have not been described in great detail. In this paper, we will review the current status of the omentum applications for the management of central nervous system disorders.

Monitoring and management of the paediatric neurosurgical patient

Head injury remains the most common cause of death in children, and tumours of the central nervous system are the most common solid tumour encountered. There is little class 1 evidence on which to base the monitoring and management of the paediatric patient with these conditions, management strategies commonly being extrapolated from those in use for adults. However, the clinical outcome for these conditions appears to be improving, with evidence suggesting that this improvement is being achieved by the management of these children in specialist centres.