OBJECTIVE: The primary purpose of this study was to develop and implement a novel Hemispheric Surgical Score to guide the treatment of pediatric patients with Moyamoya disease (MMD). Additionally, we aimed to describe a comprehensive flowchart for the evaluation, treatment, and follow-up of these patients and to share our experience with the interdisciplinary management of a large pediatric cohort at a referral pediatric hospital.
METHODS: We conducted a retrospective observational study using medical records of patients diagnosed with MMD at the Pediatric Hospital \"Prof. Dr. Juan P. Garrahan\" in Buenos Aires, Argentina, from July 2013 to July 2023. From July 2016 onward, data were analyzed prospectively following the implementation of the Hemispheric Surgical Score and the flowchart. Evaluations included clinical, MRI, and angiographic criteria, and patients were managed by an interdisciplinary team. Demographic, clinical, and neuroimaging data were collected and analyzed.
RESULTS: Eighty hemispheres from 40 patients were analyzed, with cerebral revascularization performed on 72 hemispheres from 37 patients. The Hemispheric Surgical Score and flowchart standardized treatment decisions, and reduced the need for invasive studies like angiographies for follow-up. The majority of patients (79.1%) had favorable outcomes, with complete disease progression arrest and no worsening of imaging nor clinical scores during a median follow-up of 35.8 months.
CONCLUSIONS: The Hemispheric Surgical Score and the comprehensive flowchart have improved the management of MMD in pediatric patients by standardizing treatment and reducing unnecessary invasive procedures. This interdisciplinary approach has led to better patient outcomes, highlighting the need for further validation in larger studies and comparisons of different revascularization techniques through randomized clinical trials.

暂无摘要。

Recent cohort studies on hemorrhagic and asymptomatic moyamoya disease have revealed that choroidal anastomosis, a type of fragile periventricular collateral pathway (periventricular anastomosis) typical of the disease, is an independent predictor of hemorrhagic stroke. However, treatment strategies for less-symptomatic nonhemorrhagic patients with choroidal anastomosis remain unclear. The Moyamoya Periventricular Choroidal Collateral (P-ChoC) Registry is an ongoing multicentered observational study that will test the hypothesis that extracranial-intracranial bypass prevents de novo hemorrhagic stroke in less symptomatic, nonhemorrhagic patients with choroidal anastomosis and may thus contribute to improving the prognosis of moyamoya disease. In this study, we report the study protocol of the moyamoya P-ChoC Registry and review the literature on choroidal anastomosis as a fragile collateral pathway.

BACKGROUND: Cerebral Revascularization (CR) remained an indispensable arm in the neurosurgical arsenal, especially managing symptomatic hemisphere with misery perfusion (SHMP).
METHODS: We described an a mid-aged gentleman diagnosed with progressive middle cerebral steno-occlusion following carotid endarterectomy by employing individualized arterial reconstruction with tentative clamping method (TCM) under supervision of intraoperative monitoring. An operative video was also accompanied to demonstrate further details.
CONCLUSIONS: The optimal treatment strategy for SHMP should be tailored by individuals. The risk of postoperative adverse sequel can be minimized and improved neuro-cognitive status was accomplished with an aid of TCM for such prophylactic procedure.
BACKGROUND: NA.

BACKGROUND: Revascularization surgery is recommended for all pediatric patients with moyamoya disease (MMD) with ischemic symptoms because the brains of such patients are still developing. By contrast, no clear guidelines for selective revascularization surgery in adult patients (30 years or more) with ischemic presentation have been established. Regarding the age of initial onset of ischemic MMD, patients in their 20s are at the bottom of the distribution and this age group may share features with both adult and pediatric patients. The present prospective study aimed to clarify the clinical features and treatment outcomes of patients in their 20s (younger patients) with ischemic MMD compared with patients aged 30-60 years (older patients).
METHODS: While patients with misery perfusion in the symptomatic cerebral hemisphere on 15O-positron emission tomography underwent combined surgery including direct and indirect revascularizations in the first study period and indirect revascularization alone in the second study period, patients without misery perfusion in that hemisphere received pharmacotherapy alone through the two study periods. Cerebral angiography via arterial catheterization and neuropsychological testing were performed before and after surgery.
RESULTS: During 12 years, 12 younger patients were included and comprised 6% of all adult patients (194 patients). The incidence of misery perfusion in the affected hemisphere was significantly higher in younger (12/12 [100%]) than in older patients (57/182 [31%]) (p < 0.0001). No difference in the incidence of cerebral hyperperfusion syndrome and postoperatively declined cognition was seen between younger (2/5 [40%] and 2/5 [40%], respectively) and older (11/36 [31%] and 15/36 [42%], respectively) cerebral hemispheres undergoing combined revascularization surgery. No difference in the incidence of postoperatively formed collateral flows feeding more than one-third of the middle cerebral artery cortical territory on angiograms and postoperatively improved cognition was seen between younger (9/10 [90%] and 6/10 [60%], respectively) and older (18/22 [83%] and 14/22 [64%], respectively) cerebral hemispheres undergoing indirect revascularization surgery alone.
CONCLUSIONS: Patients in their 20s with ischemic MMD always exhibit misery perfusion in the affected hemisphere, unlike older patients, and sometimes develop cerebral hyperperfusion syndrome after combined revascularization surgery, leading to cognitive decline, similar to older patients. Moreover, indirect revascularization surgery alone forms sufficient collateral circulation and restores cognitive function in patients in their 20s, similar to older patients.

OBJECTIVE: Posterior circulation cerebral bypasses often show higher risks and lower patency. Only few reports discussed occipital artery (OA)-vertebral artery (VA) bypasses. We present our illustrative cases to address current gaps in the literature on OA-VA bypass.
METHODS: A single-center retrospective review was conducted to include all institutional cases of OA-VA bypass, discussing the technique and outcomes.
RESULTS: Four institutional cases undergoing a total of 5 bypasses were evaluated, including 3 males and 1 female, with median age of 65 years (range, 62-73). All patients had vertebrobasilar insufficiency (VBI) with recurrent strokes/TIAs due to intracranial atherosclerosis, leading to unilateral VA stenosis with contralateral occlusion (1, 25%), bilateral VA stenosis (1, 25%) or occlusion (1, 25%). Medical management included aspirin for all cases (100%), with clopidogrel in 3 (75%). Surgery was performed through a far lateral approach, connecting the OA to the VA-3 segment, with no inter-positional graft. One patient underwent contralateral OA-VA bypass 6 months after the prior surgery due to worsening of the contralateral VA stenosis. Bypass patency was confirmed in all cases with post-operative angiography. All patients had clinical improvement, with one case of wound dehiscence managed conservatively. All patients were alive at last follow-up (median 7.0 months; range: 1.5-18).
CONCLUSIONS: OA-VA bypass is a challenging yet effective strategy in selected patients with VBI. Current literature lacks unique definitions of surgical indications and techniques, which we addressed in our series. Surgical education should focus on expanding the microsurgery anatomy knowledge.

BACKGROUND: In adults, moyamoya disease (MMD) often presents with slight neurocognitive impairment, which may result from frontal lobe hemodynamic insufficiency.
METHODS: In this study, we performed revascularization surgery by superficial temporal artery-anterior cerebral artery (ACA) direct bypass in 20 adults with MMD with poor anterograde ACA flow (Group M). The pre- and postoperative neurocognitive test results of these patients were retrospectively analyzed. The comparative group (Group C) included 23 patients with unruptured aneurysms or brain tumors who underwent craniotomy, as well as the same neurocognitive tests as Group M. We calculated the compositive frontal lobe function index (CFFI) based on the results of seven neurocognitive tests for each patient, and the difference between the pre- and postoperative CFFI values (CFFI Post - Pre) was compared between the two groups.
RESULTS: Frontal perfusion improved postoperatively in all patients in Group M. The CFFI Post - Pre was significantly higher in Group M than in Group C (0.23 ± 0.44 vs. - 0.20 ± 0.32; p < 0.001). After adjusting for postoperative age, sex, preoperative non-verbal intelligence quotient, and preoperative period of stress, Group M had a significantly higher CFFI Post - Pre than Group C in the multiple regression analysis (t value = 4.01; p < 0.001).
CONCLUSIONS: Improving frontal lobe hemodynamics might be the key for improving neurocognitive dysfunction in adults with MMD. The surgical indication and method should be considered from the perspective of both stroke prevention and neurocognitive improvement or protection.

Background: Brachiocephalic steal is a rare phenomenon that may lead to hemodynamic abnormalities in the ipsilateral vertebral and carotid arteries. Current treatment includes management of vascular risk factors, endovascular stenting, and surgical management depending on the severity of symptoms. Case Information: We describe a patient with multiple vascular risk factors who presented with mild neurological symptoms and chronic right arm weakness associated with concurrent brachiocephalic steal and right MCA M1 stenosis on neuroimaging. Use of right superficial temporal artery to middle cerebral artery bypass and aorta-right subclavian bypass resulted in improved flow to the right hemisphere on quantitative magnetic resonance angiography and single-photon emission computed tomography, significantly lowering the risk of catastrophic ischemic stroke. Conclusion: Complex steal phenomena increase stroke risk. In cases of high-grade occlusion or advanced symptoms, endovascular or surgical management should be considered for optimal stroke prevention.

The horizontal part of the third segment (V3) of the vertebral artery (VA) is a critical anastomotic site for bypass procedures involving either donor or recipient vessels. It is rare for the V3 segment to deviate from its typical course of passing through the atlanto-transverse foramen. V3 anomaly encountered in occipital artery (OA)-V3 bypass surgery has not been previously reported. Here, we present a case involving a patient undergoing bypass surgery due to recurrent post-stent occlusion at the first segment (V1) of the left VA. During the operation, it was noted that the V3 horizontal segment could not be identified within the left VA groove, leading to initial suspicion of left V3 disuse atrophy attributed to prolonged chronic ischaemia. Consequently, there was a need to modify the operative method and to transition from an OA-V3 bypass to an OA-posterior inferior cerebellar artery bypass. Post-operative computed tomography angiography confirmed that indeed, the left V3 did not traverse through the transverse foramen of the atlas and instead entered the dural membrane between the first cervical vertebra (C1) and the second cervical vertebra (C2).

BACKGROUND: Recent advances are in the genetics, diagnosis, pathophysiology, and management of moyamoya disease (MMD), and moyamoya syndrome (MMS), a term used to describe moyamoya-like vasculopathy associated with various systemic diseases or conditions.
CONCLUSIONS: Ring finger protein (RNF213) has been reported to be a susceptibility gene not only for MMD but also for atherosclerotic intracranial arterial stenosis and ischemic stroke attributable to large artery atherosclerosis. The latest guidelines by the Research Committee on MMD of the Japanese Ministry of Health, Labor, and Welfare, removed limitations of the previous definition that required bilateral involvement of the intracranial carotid artery to make the diagnosis, given the increasing evidence of progression to bilateral involvement in unilateral MMD. 3-dimensional constructive interference in steady-state MRI is useful for the differential diagnosis of MMD from atherosclerosis. Recent advances in the pathophysiology of MMD suggest that genetic and environmental factors play important roles in vascular angiogenesis and remodeling via complex mechanisms. The latest Japanese Guidelines and American Scientific Statement described that antiplatelet therapy can be considered reasonable. Endovascular interventional stent placement fails to prevent ischemic events and does not halt MMD progression. In the Japan Adult Moyamoya trial, a randomized controlled trial for bilateral extracranial-intracranial direct bypass versus conservative therapy in patients with MMD, who had intracranial hemorrhage, recurrent bleeding, completed stroke, or crescendo transient ischemic attack was significantly fewer with direct bypass than with conservative care.
CONCLUSIONS: This review presents updated information on genetics, diagnosis, pathophysiology, and treatment of adult MMD and MMS. Despite recent advances, many mysteries still exist in the etiologies of moyamoya vasculopathy. The diagnostic criteria and treatment guidelines have been updated but not yet been globally established. Ongoing and future studies investigating underlying pathophysiological mechanisms of MMD and MMS may clarify potentially effective medical, surgical, or endovascular treatments.