Revascularization For Moyamoya Disease Research Articles

Postoperative stroke and neurological outcomes in the early phase after revascularization surgeries for moyamoya disease: an age-stratified comparative analysis.

Stroke and neurological outcomes in the early phase following revascularization for moyamoya disease (MMD) may depend on the patient's age. In this study, an age-stratified comparative analysis was performed to clarify this issue. We reviewed 105 MMD patients who underwent 179 revascularization surgeries. The demographic characteristics were collected in four age groups (≤ 5 and 6-17years for pediatric patients and 18-49 and ≥ 50years for adults). Additionally, we assessed the incidence of subsequent stroke and deterioration of modified Rankin Scale (mRS) score. Then, we evaluated predictors of postoperative stroke and mRS deterioration using logistic regression. The mean patient age was 26.2 ± 18.5years. No significant difference in the incidence of postoperative stroke was observed between age groups; however, the incidence tended to be increased among patients aged ≤ 5years (17.9%) and patients aged ≥ 50years (16.7%). Deterioration of mRS scores was significantly associated with ages ≤ 5years (17.9%) and ≥ 50years (11.1%). Logistic regression showed that posterior cerebral artery involvement (odds ratio [OR], 4.6) and postoperative transient neurological events (TNEs) (OR, 5.93) were risk factors for postoperative stroke. Age ≤ 5years (OR, 9.73), postoperative TNEs (OR, 7.38), and postoperative stroke (OR, 49) were identified as predictors of unfavorable neurological outcomes. The novel feature of this comparative analysis by age group is that membership in the early-childhood MMD patient group (under 5years old) was an independent risk factor for unfavorable short-term neurological outcomes and was mainly associated with the incidence of postoperative severe cerebral infarction.

Intraoperative Early Venous Filling Phenomenon as an Intrinsic Sign of the Local Hemodynamic Change after Revascularization Surgery in a Patient with Adult Moyamoya Disease: Implications of a Potential Arteriovenous Shunt

After revascularization surgery for patients with moyamoya disease (MMD), local and global hemodynamic changes occur intraoperatively and in the early postoperative period. Local cerebral hyperperfusion and watershed shift ischemia are well-known perioperative pathologies after revascularization for MMD, but early venous filling phenomenon is markedly rare. We report the case of a 19-year-old woman with hemorrhagic-onset MMD who presented with grand mal seizure and subarachnoid hemorrhage. She underwent superficial temporal artery (STA)–middle cerebral artery (MCA) anastomosis combined with indirect pial synangiosis on the affected hemisphere. Intraoperatively, notable early arterial blood filling in the fine cortical vein was observed around the site of anastomosis right after the STA–MCA anastomosis under the surgical microscope and fluorescence indocyanine green video angiography. Recovery of consciousness after general anesthesia was normal, although she exhibited a focal seizure 1 hour later. Postoperative magnetic resonance imaging was not remarkable, and cerebral hemodynamics significantly improved in the acute stage after surgical revascularization. Considering the intrinsic vulnerability of the microvascular anatomy of MMD, the present case is notable because early venous filling was observed intraoperatively. This phenomenon suggests the existence of a potential arteriovenous shunt as an underlying pathology of MMD, but its implications in the early postoperative course should be further verified in a larger number of MMD patients undergoing surgical revascularization.

Incidental De Novo Cerebral Microhemorrhages are Predictive of Future Symptomatic Macrohemorrhages After Surgical Revascularization in Moyamoya Disease.

Patients with moyamoya disease who develop incidental cerebral microhemorrhages (CMHs) on magnetic resonance imaging (MRI) have higher risk of developing subsequent symptomatic repeat macro hemorrhages. To evaluate the effect of surgical revascularization on development of de novo CMHs and assess its correlation with repeat hemorrhage rates and functional outcome in hemorrhagic onset moyamoya disease (HOMMD). We retrospectively reviewed a prospectively managed departmental database of all patients presenting with HOMMD treated between 1987 and 2019. The search yielded 121 patients with adequate MRI follow-up for inclusion into the study. In total, 42 preoperative CMHs were identified in 18 patients (15%). Patients presenting with preoperative CMH were more likely to develop de novo CMH after surgical revascularization. 7 de novo CHMs were identified in 6 patients (5%) on routine postoperative MRI at distinct locations from previous sites of hemorrhage or CMH. Symptomatic repeat macro hemorrhage was confirmed radiographically in 15 patients (12%). A total 5 (83%) of 6 patients with de novo CMHs later suffered symptomatic repeat macro hemorrhage with 4 of 5 (80%) hemorrhages occurring at sites of previous CMH. On univariate and multivariate analysis, de novo CMHs was the only significant variable predictive for developing repeat symptomatic hemorrhage. Development of delayed repeat symptomatic hemorrhage was prognostic for higher modified Rankin Score and therefore poorer functional status, whereas preoperative functional status was predictive of final outcome. De novo CMHs after surgical revascularization might serve as a radiographic biomarker for refractory disease and suggest patients are at risk for future symptomatic macro hemorrhage.

Incidental De-novo Cerebral Micro-hemorrhages are Predictive of Future Symptomatic Macro-hemorrhages after Surgical Revascularization in Moyamoya Disease

Incidental De-novo Cerebral Micro-hemorrhages are Predictive of Future Symptomatic Macro-hemorrhages after Surgical Revascularization in Moyamoya Disease

Preoperatively estimated graft flow rate contributes to the improvement of hemodynamics in revascularization for Moyamoya disease

Objectives: Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass operation is an effective treatment for patients with Moyamoya disease, and the hemodynamic parameters are reported to be improved after operation. However, there is no report concerning hemodynamic changes from the viewpoint of the preoperative anatomical structure of grafts. In this study, we evaluated the correlation between the preoperatively estimated blood flow of the graft obtained through image-based computational fluid dynamics (CFD) analysis and the hemodynamic changes in the acute phase after revascularization. Materials and methods: A total of 30 hemispheric sides of 23 patients were examined. The blood flow, that is, flow rate (FR) of the STA branches that were anastomosed to the MCA was evaluated using CFD analysis based on computed tomography (CT) angiography imaging data. The correlations between the FR and the hemodynamic changes in the acute phase after revascularization obtained through CT perfusion were assessed. Results: The preoperatively estimated FR of the graft was moderately correlated with the changes in the mean transit time significantly and weakly correlated with those in the cerebral blood flow and cerebral blood volume. In addition, the FR was strongly correlated with age and the diameter of the STA from the origin to the bifurcation.Conclusion: The preoperatively estimated FR of the graft obtained through image-based CFD analysis contributed to the improvement of the mean transit time after revascularization. Because the FR of the graft was associated with the diameter of the STA, the size of the STA might be an important factor in postoperative hemodynamic changes. This might lead to the risk assessment of acute drastic hemodynamic changes as cerebral hyperperfusion, and consequently, better surgical outcomes might be expected.

Intraoperative transit-time ultrasonography combined with FLOW800 predicts the occurrence of cerebral hyperperfusion syndrome after direct revascularization of Moyamoya disease: a preliminary study.

Cerebral hyperperfusion syndrome (CHS) is a common complication after direct bypass surgery in patients with Moyamoya disease (MMD). Since preventive measures may be inadequate, we assessed whether the blood flow difference between the superficial temporal artery (STA) and recipient vessels (△BF) and the direct perfusion range (DPR) are related to CHS. We measured blood flow in the STA and recipient blood vessels before bypass surgery by transit-time probe to calculate △BF. Perfusion changes around the anastomosis before and after bypass were analyzed with FLOW800 to obtain DPR. Multiple factors, such as △BF, DPR, and postoperative CHS, were analyzed using binary logistic regression. Forty-one patients with MMD who underwent direct bypass surgery were included in the study. Postoperative CHS symptoms occurred in 13/41 patients. △BF and DPR significantly differed between the CHS and non-CHS groups. The optimal receiver operating characteristic (ROC) curve cut-off value was 31.4ml/min for ΔBF, and the area under the ROC curve (AUC) was 0.695 (sensitivity 0.846, specificity 0.500). The optimal cut-off value was 3.5cm for DPR, and the AUC was 0.702 (sensitivity 0.615, specificity 0.750). Postoperative CHS is caused by multiple factors. △BF is a risk factor for CHS while DPR is a protective factor against CHS.

STA-enhanced vascularized galeal flap for revascularization of moyamoya disease: technical report.

A variety of revascularization techniques have been reported for the management of moyamoya disease to prevent risks of stroke. STA (superficial temporal artery)-MCA (middle cerebral artery) microanastomosis, single or double bypass, with temporal muscle or galeal onlay graft has been the standard operative procedure. Our rationale of revascularization surgery has been a combination of STA-MCA double bypass using the frontal and the parietal branches of STA and transfer of a highly vascularized thick galeal flap with maintained STA vasculature. This STA-enhanced vascularized galeal flap graft is extremely effective for revascularization of moyamoya disease.

Quantitative Angiographic Hemodynamic Evaluation After Revascularization Surgery for Moyamoya Disease

The corresponding hemodynamic changes of the internal carotid artery (ICA) after the revascularization surgery for moyamoya disease (MMD) remain unclear. The aim of this study was to analyze the hemodynamic changes of the ipsilateral ICA after the combined direct and indirect extracranial-intracranial (EC-IC) bypass. MMD patients undergoing combined EC-IC bypass were retrospectively reviewed. The mean transit time (MTT) of ICA was evaluated by color-coding angiography before revascularization and at follow-up. The MTT defined as the blood transit time between the end of cervical portion (C1) and the C7 segment of ICA. The clinical prognosis was assessed with Matsushima grading system, moyamoya vessel reduction system, and modified Rankin Scale (mRS). The correlation between hemodynamic parameter and prognosis was analyzed. Subgroup analysis was conducted between different presentations and different ages. Fifty-one patients were identified and the mean imaging follow-up interval was 5.5 months. The ICA-MTT was increased after the combined revascularization (P < 0.001) compared with contralateral ICA. Faster preoperative ICA-MTT was significantly associated with improved mRS in the ischemic group (P = 0.05). The increased ICA-MTT was significantly associated with favorable neoangiogenesis (P = 0.04), moyamoya vessel reduction (> 50%) (P = 0.023), and improved mRS score (P = 0.008). In subgroup analysis, the correlation in the ischemic subgroup and adult subgroup remained significant. In this cohort, the ICA-MTT increased after the combined EC-IC bypass, and there was a positive correlation between the increased blood transit time and favorable outcomes. Color-coding DSA proved to be useful as a quantitative and serial method to monitor postoperative courses after revascularization in MMD.

Perfusion Quantification using Arterial Spin Labeling Magnetic Resonance Imaging after Revascularization for Moyamoya Disease.

The hemodynamics in the brains of individuals with Moyamoya disease are complex and variable. Cerebral revascularization is an important treatment when hemodynamics are severely damaged. It's of great value to accurately quantify blood perfusion of different functional brain regions for better postoperative prognosis. In this study, we developed methods to segment territory of middle cerebral arteries (MCA) and its functional brain regions based on T1 and arterial spin labeling (ASL) imaging, absolute and normalized cerebral blood perfusion (CBF) were calculated for target regions-of-interest (ROI), spatial coefficient of variation was introduced to detect information of arterial transit time (ATT) contained in CBF images. After revascularization of Moyamoya disease, we detected perfusion improvement within MCA territory, while different alterations exist within different functional sub-regions. We also conformed that the spatial coefficient of variation of ASL CBF images can be used as an alternative ROI-based hemodynamic measurement to predict alterations of ATT. In summary, our methods show potential in postoperative evaluation of patients with Moyamoya disease.

Predictors of neoangiogenesis after indirect revascularization in moyamoya disease: a multicenter retrospective study.

The effect of indirect revascularization to improve cerebral perfusion for moyamoya disease (MMD) is based on ingrowth of new vessels into the cortical brain. Preoperative indicators for neoangiogenesis would be helpful to the selection of appropriate procedures for MMD patients but have not yet been investigated. Our study aimed to identify potential predictors for neovascularization after indirect bypass surgery. The authors reviewed consecutive cases with complete clinical and radiological documentation of patients who had undergone surgery between December 2010 and January 2018. Patients who were treated with indirect bypass surgery were included. Cerebrovascular characteristics were evaluated by catheter angiography. Neoangiogenesis after indirect bypass was determined as "good" or "poor" based on the Matsushima standard. Univariate and multivariate analyses were performed to identify predictors for neoangiogenesis after indirect bypass. Subgroup analyses by onset type and surgical type were carried out to identify specific predictors for different populations. In total, 231 hemispheres of 209 patients (mean ± SD age 23.06 ± 15.09 years, range 3-61 years) were retrospectively included. In 146 (63.2%) hemispheres, good neoangiogenesis was observed after indirect revascularization. Multivariate analysis showed that the status of ICA moyamoya vessels (p < 0.001, OR [95% CI] 3.242 [2.007-5.236]) is a predictor of favorable neoangiogenesis after indirect bypass surgery, whereas hemorrhagic onset (p < 0.001, OR [95% CI] 0.138 [0.054-0.353]) is a risk factor for poor neoangiogenesis. In addition, younger age was significantly associated with good neovascularization in patients with hemorrhagic onset (p = 0.027, OR [95% CI] 0.893 [0.808-0.987]), whereas age was not a significant predictor for neovascularization in non-hemorrhagic-onset patients (p = 0.955). Hemispheres with good revascularization had lower incidence of rebleeding, lower modified Rankin Scale scores, and more improvement of symptoms during long-term follow-up (p = 0.026, 0.006, and 0.013, respectively). Hemorrhagic onset predicts poor neovascularization after indirect bypass surgery for MMD patients. Abundant ICA moyamoya vessels indicate good neoangiogenesis after indirect bypass and vice versa, whereas absent ICA moyamoya vessels predict poor revascularization. Good neovascularization was associated with better long-term outcome. Future studies are needed to further address this issue and clarify the underlying pathophysiological mechanisms.

An experimental study on antispasmodic treatment of superficial temporal artery graft during revascularization for moyamoya disease

Objective To compare the antispasmodic effects of nitroglycerin, nimodipine and diltiazem on the superficial temporal artery(STA) during the superficial temporal artery-middle cerebral artery bypass (STA-MAC). Methods A total of sixty- five patients with moyamoya disease who underwent STA-MAC were divided into three groups according to random number table. GroupⅠ was administered nitroglycerin (n=22), groupⅡ was given nimodipine (n=22), and group Ⅲ was given diltiazem (n=21). The patients were continuously pumped with 0.3-0.5 μg·kg-1·min-1 during the surgery. Then, the maximum flow velocity (Vmax), the minimum flow velocity (Vmin), the mean flow velocity (Vm), resistance index (RI), and inside diameter (ID) of the STA before graft (T1), immediately after extubation (T2) and three days after operation (T3) were recorded using vascular ultrasound. Meanwhile, the mean arterial pressure (MAP), heart rate and central venous pressure (CVP) were recorded. Results The three groups showed remarkably increased Vmax, Vmin, and Vm, and ID and decreased RI at T3 compared with those at T1 (P 0.05). Conclusions Nimodipine and diltiazem are superior to nitroglycerin in the diastolic and antispasmodic effects on STA-MAC. Key words: Moyamoya disease; Superficial temporal artery-middle cerebral artery bypass; Nitroglycerin; Nimodipine; Diltiazem

Strategies for and Outcome of Repeat Revascularization Surgery for Moyamoya Disease: An American Institutional Series.

Revascularization for moyamoya disease (MMD) effectively prevents future ischemic events. However, small subsets of patients with persistent or new symptoms due to inadequate collateralization require repeat revascularizations. To investigate the clinical and radiological outcome of repeat revascularization in MMD patients with previous indirect or direct bypasses. Single institution, retrospective analysis of a prospective MMD database. From 1991 to 2014, this institution performed 1244 revascularization bypasses (1107 direct, 137 indirect) in 765 patients, of whom 57 were repeat revascularizations (38 indirect, 19 direct bypass). When initially performed at the institution, the repeat revascularization rate was 4% for indirect and 1% for direct bypasses (P = .03). Cohorts with previous indirect vs direct bypass were slightly younger (mean age 23 vs 30 yr), with fewer females (61% vs 84%, P = .08), and a similar mean duration between initial bypass and repeat revascularization (49 vs 47 mo). Both groups had similar repeat revascularization due to transient ischemic attacks (66% vs 63%). One acute graft occlusion in the previous direct bypass group was revised within 1 wk postoperatively. Over 50% of the repeat revascularizations in both groups were direct bypasses; the major difference being that the repeat bypass in the direct group was to augment another vascular territory. At nearly 5 yr mean follow-up, over 80% of patients in both groups are well, free from stroke/transient ischemic attack symptoms, with excellent radiological results. Repeat revascularization can safely and effectively prevent future ischemic events. Indirect bypass has a higher rate of repeat revascularization than direct bypass.

Treatment of moyamoya phenomenon in Thailand: A comparison between medical treatment and surgical revascularization

Background: Surgical revascularization in moyamoya disease mainly aimed to improve cerebral hemodynamics and reduce stroke events. It is also believed that the procedures also help washout of thromboemboli. With the same mechanism, antithrombotic agents are potentially useful; however, no comparison between surgical and medical interventions has been stated in Thailand.

Effect of Intraoperative Anesthetic Management on Patient Outcomes for Surgical Revascularization for Moyamoya Disease: A 7-year Retrospective Study

Effect of Intraoperative Anesthetic Management on Patient Outcomes for Surgical Revascularization for Moyamoya Disease: A 7-year Retrospective Study

Direct Anastomosis Using Occipital Artery for Additional Revascularization in Moyamoya Disease After Combined Superficial Temporal Artery-Middle Cerebral Artery and Indirect Bypass.

The posterior cerebral artery (PCA) is involved in approximately 30% of moyamoya disease (MMD) cases. However, there have been insufficient reports describing revascularization techniques in the posterior portion of the brain, particularly of direct anastomosis. To perform a technical assessment in patients with MMD who underwent either occipital artery (OA)-PCA bypass or OA-middle cerebral artery (MCA) bypass. A total of 428 revascularization procedures in 368 patients were retrospectively assessed by reviewing clinical charts and radiological data. Ten patients (3.5%) were treated with direct bypass after the anterior revascularization with a median interval of 30months (range, 5months-16years). Seven patients were < 18years of age (average age, 17.5 ± 15.6years). Preoperative symptoms included transient motor deficits involving the lower extremities (n = 5), visual disturbances (n = 6), and cerebral infarctions (n = 6). A favorable outcome (modified Rankin Scale score < 3) was achieved in 9 of these 10 patients. Direct anastomosis was performed in 3hemispheres with an OA-MCA bypass and in 8hemispheres with an OA-PCA bypass. Patency of the direct bypass was confirmed on angiogram in 7 of 7 patients who underwent conventional angiogram performed within 1year after the surgery. None of the 10 patients demonstrated cerebral infarctions after the posterior revascularization. In MMD, symptomatic PCA regression after anterior revascularization was found predominantly in children and young adults. Direct anastomosis in the posterior portion of the brain can be successfully achieved and is effective in preventing ischemic events.

BOLD-fMRI with median nerve electrical stimulation predict hemodynamic improvement after revascularization in patients with moyamoya disease.

To assess the severity of cerebral hemodynamic impairment and hemodynamic improvements, after revascularization in moyamoya disease (MMD) by means of blood-oxygen-level dependent functional magnetic resonance imaging (BOLD-fMRI). BOLD-fMRI with median nerve electrical stimulation based on echo planar imaging was performed in 73 volunteers with MMD and 15 healthy volunteers using a 3.0 Tesla MRI scanner. Twenty-four MMD patients were reexamined after encephaloduroarteriosynangiosis. Time-signal intensity curves of the activated area of the contralateral primary somatosensory cortex were computed. Negative response time (Tnr) and peak (Pnr), positive response time (Tpr) and peak (Ppr), and time to negative peak (TTPn) and positive peak (TTPp) were measured. Compared with nonparesthesia group and the asymptomatic side of paresthesia group, the patients with paresthesia showed extended Tnr (22.04 ± 3.34 s versus 9.57 ± 2.27 s and 12.67 ± 2.69 s, P = 0.0096), decreased Pnr (-0.47 ± 0.06 versus -0.30 ± 0.09 and -0.33 ± 0.09, P = 0.010), delayed TTPn (9.04 ± 1.39 s versus 3.66 ± 0.79 s and 4.88 ± 1.10 s, P = 0.0064), shortened Tpr (22.75 ± 2.30 s versus 36.85 ± 2.68 s and 33 ± 2.49 s, P = 0.0010), and decreased Ppr (0.62 ± 0.08 versus 0.99 ± 0.15 and 0.97 ± 0.11, P = 0.0149) when subjected to median nerve electrical stimulation in the symptomatic side. After surgery, the patients with paresthesia showed shorter Tnr (1.53 ± 1.66 s versus 17.88 ± 22.61 s, P = 0.0002), increased Pnr (-0.14 ± 0.17 versus -0.44 ± 0.53, P = 0.0178), advanced TTPn (1.29 ± 1.21 s versus 7.29 ± 8.21 s, P = 0.0005), extended Tpr (36.94 ± 6.41 s versus 25.18 ± 15.51 s, P = 0.0091), increased Ppr (1.21 ± 0.87 versus 0.77 ± 0.60, P = 0.0201), and advanced TTPp (11.18 ± 4.70 s versus 27.29 ± 20.00 s, P = 0.0046). Bold-fMRI is useful to assess disease severity and surgical efficacy in MMD. 1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2017;46:1159-1166.

Abstract TP133: Interactive Development of Direct and Indirect Bypass After Combined Revascularization for Moyamoya Disease: The Significance of Indirect Bypass

Background &amp; Purpose: The additional effects of indirect bypass on combined revascularization surgery in moyamoya disease (MMD) remain unclear. Our purpose in this study is to evaluate how direct and indirect bypass in combined revascularization change through long term follow up and to analyze the clinical factors or hemodynamic parameters involved in these changes. Methods: A retrospective survey was conducted with a sample size of 97 hemispheres from 69 consecutive patients (43 adults and 26 children) with MMD treated by combined revascularization. We used magnetic resonance angiography (MRA) to evaluate bypass development with the diameters of superior temporal artery (STA) for the direct bypass and middle meningeal artery (MMA) and deep temporal artery (DTA) for the indirect bypass. A multivariate logistic regression analysis was used to study the related multiple variables on bypass development. Results: Good indirect bypass indicated by MMA development was seen 78% of the adult hemispheres and 95% of the pediatric ones. Dual development of direct and indirect bypasses was most frequently observed (47% and 56% of the adult and pediatric hemispheres, respectively). When indirect bypasses developed, 28% of the STAs reduced in diameter reciprocally from the acute to the chronic phases after surgery. The development of indirect bypass was significantly better in the adult hemispheres at Suzuki stage 4 or greater ( P =0.02; odds ratio 7.4, 95% confidence interval, 1.4-39.4). The disease onset type and the hemodynamic parameters were not associated with the development of surgical revascularization. Conclusions: Indirect bypass developed effectively in both adult and pediatric patients, even in the presence of direct bypass. The universal application of indirect bypass is considered an optimal surgical strategy to maximize revascularization in MMD.

Establishment of collateral circulation in patients with moyamoya disease after combined revascularization

Objective To observe the establishment of postoperative collateral circulation and its types after the combined revascularization for the treatment of patients with moyamoya disease. Methods From January 2010 to January 2015, 57 patients with moyamoya disease (67 hemispheres) treated with direct vascular reconstruction (superficial temporal artery-middle cerebral artery anastomosis, STA-MCA) combined with indirect vascular reconstruction (encephalo-duro-myo-synangiosis, EDMS) at the Department of Neurosurgery, Brain Hospital Affiliated to Nanjing Medical University were analyzed retrospectively. Head CT or MR perfusion imaging was use to evaluate cerebral blood flow. According to the digital subtraction angiography (DSA) images, the establishment of collateral circulation after procedure (the cerebral hemisphere blood supply range) was evaluated. The blood supply range of revascularization of 2 surgical methods after procedure was compared. Results The postoperative follow-up was 6-60 months (mean, 23±12 months). At 6 months after procedure, 60 (89.6%) of 67 hemispheres showed increased cerebral blood flow perfusion on the operated sides. The direct vascular anastomosis was patent in 65 sides (97.0%). DSA showed that the feeding range of neovascularization in patients ≥1/3 of the middle cerebral artery (MCA) blood supply region accounted for 97.0% (65 sides), among them, in patients >2/3 blood supply region accounted for 82.1% (55 sides). The neovascularization was sparse only in 2 sides, and the blood supply range the indirect one; and 23 sides (34.3%) were < the indirect revascularization blood supply range; and 25 sides (37.3%) were equal to the indirect revascularization blood supply range. At 6 months after procedure, there was no significant difference in the establishment of collateral circulation between the patients with ischemic and hemorrhagic moyamoya disease. Conclusions The effect of the direct revascularization combined with the indirect revascularization for the treatment of revascularization of moyamoya disease is better. The direct revascularization may immediately improve the cerebral perfusion in ischemic area, while the indirect revascularization may provide a more lasting effect of revascularization. Key words: Moyamoya disease; Cerebral revascularization; Collateral circulation

Outcome of revascularization in moyamoya disease: Evaluation of a new angiographic scoring system.

Background:Moyamoya disease (MMD) is a chronic progressive cerebrovascular occlusive disease affecting commonly the anterior circle of Willis. Matushima grade inadequately reflects the angiographic changes postrevascularization procedure.Aims:To analyze the clinical and angiographic outcome of revascularization procedures (direct [ST-middle cerebral artery (MCA) anastomosis] and indirect [encephalo-duro-arterio-myo-synangiosis (EDAMS)]) in MMD and validate a new angiographic scoring system.Materials and Methods:Retrospective study included symptomatic patients of MMD who underwent revascularization; both indirect and combined methods between January 2002 and April 2012. Follow-up angiography was done after at least 3 months. We devised a novel scoring system the “angiographic outcome score” (AOS) including reformation of distal MCA and anterior cerebral artery, regression of basal moyamoya vessels, leptomeningeal collaterals and overall perfusion. AOS was applied to the angiograms independently by a neuroradiologist and a neurosurgeon that were blinded toward its preoperative or postoperative status.Results:Totally 33 patients underwent 36 EDAMS and 4 combined procedures (EDAMS + ST-MCA bypass). The mean follow-up was 20 months. None had recurrent transient ischemic attack or fresh infarct. Postoperative AOS was significantly higher than preoperative AOS. The Spearman rho showed positive correlation between Matushima grade and postoperative AOS. Significant regression of basal moyamoya vessels and increase in number of loci of transdural collaterals was seen.Conclusions:EDAMS is a simple yet effective method of revascularization in both pediatric as well as adult age groups. AOS is a simple, precise and easily reproducible scoring system, which reflects the favorable angiographic changes after revascularization.

Laparoscopic harvesting of omental pedicle flap for cerebral revascularization in children with moyamoya disease

IntroductionAn abundance of angiogenic and immunologic factors makes the omentum an ideal tissue for reconstruction and revascularization of a variety of extraperitoneal wounds and defects. Omental harvesting was historically performed through a large laparotomy and subcutaneous tunneling to the site of disease. Several complications of the open procedure including abdominal wound infection, fascial dehiscence, ventral hernia, and postoperative ileus have been described. The use of laparoscopy to harvest the omentum has the potential to reduce such complications. We describe the surgical technique and outcomes of a series of patients undergoing laparoscopic pedicled omental flap mobilization for cerebral revascularization in moyamoya disease. MethodsA retrospective chart review of all patients undergoing laparoscopic omental cerebral transposition for moyamoya disease between 2011 and 2014 was performed. Clinical indication, surgical technique, operative times, complications, and outcomes at follow-up were reviewed. ResultsA total of 7 children underwent the procedure. The general surgery team performed laparoscopic omental mobilization, extraperitonealization, and subcutaneous tunneling, while the neurosurgical team performed craniotomy and cerebral application of the graft. The patients were followed postoperatively with clinic visits and angiography. There was one intraoperative complication (colon injury) and one postoperative complication (intermittent omental hernia at fascial defect for pedicle). All patients had partial to complete symptomatic resolution and demonstrated adequate intracranial revascularization on angiography. ConclusionLaparoscopic omental pedicle flap mobilization and subcutaneous transposition is feasible in children who require salvage cerebral revascularization for moyamoya disease. The procedure should be considered for other conditions requiring extraperitoneal revascularization.