Revascularization Surgery For Moyamoya Disease Research Articles

Combined Direct and Indirect Revascularisation With Superficial Sparing of Temporalis Muscle in Moyamoya Disease: Operative Technique: 2-Dimensional Operative Video.

The primary objective of revascularization surgery for moyamoya disease (MMD) is to augment cerebral blood flow and prevent disease progression.1 There are several options for bypass surgery, including direct methods such as superficial temporal artery-middle cerebral artery anastomosis, indirect bypasses such as encephalomyosynangiosis, encephaloduroarteriosynangiosis or encephaloduroarteriomyosynangiosis, or combined procedures.2-5 In our institution, we undertake a combined approach involving multiple low-flow bypasses and a modified indirect bypass technique, with additional attention to achieving an optimal cosmetic result. Given that MMD often affects young patients, considering cosmesis as a significant factor in managing this condition should be standard practice. We present our modified operative technique of a combined approach to revascularization surgery in patients with MMD with particular emphasis on the indirect bypass procedure. The temporalis muscle is divided in two parts in the sagittal plane where the deeper portion is mobilized to perform an EMS, and the superficial portion is reattached to the bone flap to maintain cosmetic symmetry. A 23-year-old woman presented with a 6-month history of transient left-sided hemiparesis on a background of MMD (previous left-sided revascularization surgery). Subsequent imaging demonstrated worsening right internal carotid artery stenosis. The patient and her family were extensively counseled and decision to proceed with right-sided bypass surgery was undertaken (Video). The patient had an unremarkable postoperative course and was discharged home on day 14. Institutional review board approval was not required in our institution. The patient consented to the procedure and to the publication of his/her images.

Hemoglobin Drop is Associated with Early Post-operative Stroke Following Revascularization Surgery for Moyamoya Disease.

Postoperative stroke is a potentially devastating neurological complication following surgical revascularization for Moyamoya disease. We sought to evaluate whether peri-operative hemoglobin levels were associated with the risk of early post-operative stroke following revascularization surgery in adult Moyamoya patients. Adult patients having revascularization surgeries for Moyamoya disease between 1999-2022 were identified through single institutional retrospective review. Logistic regression analysis was used to test for the association between hemoglobin drop and early postoperative stroke. In all, 106 revascularization surgeries were included in the study. A stroke occurred within 7 days after surgery in 9.4% of cases. There were no significant associations between the occurrence of an early postoperative stroke and patient age, gender, or race. Mean postoperative hemoglobin drop was greater in patients who suffered an early postoperative stroke compared with patients who did not (2.3±1.1g/dL vs. 1.3±1.1g/dL, respectively; P=0.034). Patients who experienced a hemoglobin drop post-operatively had 2.03 times greater odds (95% confidence interval, 1.06-4.23; P=0.040) of having a stroke than those whose hemoglobin levels were stable. Early postoperative stroke was also associated with an increase in length of hospital stay (P<0.001), discharge to a rehabilitation facility (P=0.014), and worse modified Rankin scale at 1 month (P=0.001). This study found a significant association between hemoglobin drop and early postoperative stroke following revascularization surgery in adult patients with Moyamoya disease. Based on our findings, it may be prudent to avoid hemoglobin drops in Moyamoya patients undergoing surgical revascularization.

Development and validation of machine learning models to predict postoperative infarction in moyamoya disease.

Cerebral infarction is a common complication in patients undergoing revascularization surgery for moyamoya disease (MMD). Although previous statistical evaluations have identified several risk factors for postoperative brain ischemia, the ability to predict its occurrence based on these limited predictors remains inadequately explored. This study aimed to assess the feasibility of machine learning algorithms for predicting cerebral infarction after revascularization surgery in patients with MMD. This retrospective study was conducted across two centers and harnessed data from 512 patients with MMD who had undergone revascularization surgery. The patient cohort was partitioned into internal and external datasets. Using perioperative clinical data from the internal cohort, three distinct machine learning algorithms-namely the support vector machine, random forest, and light gradient-boosting machine models-were trained and cross-validated to predict the occurrence of postoperative cerebral infarction. Predictive performance validity was subsequently assessed using an external dataset. Shapley additive explanations (SHAP) analysis was conducted to augment the prediction model's transparency and to quantify the impact of each input variable on shaping both the aggregate and individual patient predictions. In the cohort of 512 patients, 33 (6.4%) experienced postrevascularization cerebral infarction. The cross-validation outcomes revealed that, among the three models, the support vector machine model achieved the largest area under the receiver operating characteristic curve (ROC-AUC) at mean ± SD 0.785 ± 0.052. Notably, during external validation, the light gradient-boosting machine model exhibited the highest accuracy at 0.903 and the largest ROC-AUC at 0.710. The top-performing prediction model utilized five input variables: postoperative serum gamma-glutamyl transpeptidase value, positive posterior cerebral artery (PCA) involvement on preoperative MRA, infarction as the rationale for surgery, presence of an infarction scar on preoperative MRI, and preoperative modified Rankin Scale score. Furthermore, the SHAP analysis identified presence of PCA involvement, infarction as the rationale for surgery, and presence of an infarction scar on preoperative MRI as positive influences on postoperative cerebral infarction. This study indicates the usefulness of employing machine learning techniques with routine perioperative data to predict the occurrence of cerebral infarction after revascularization procedures in patients with MMD.

Development of the external carotid artery system including the middle temporal artery after direct-indirect revascularization surgery for moyamoya disease

BackgroundThe aim of this study was to clarify when and from which blood vessels indirect revascularization develops after combined revascularization surgery for moyamoya disease and how the donor vessels that undergo direct revascularization change in the medium to long term. In particular, we focused on the middle temporal artery (MTA), which has not received much attention in indirect revascularization surgery for moyamoya disease until now. MethodsWe targeted 20 sides that were suitable for evaluating the diameter of the external carotid artery system involved in combined revascularization surgery among moyamoya disease patients who underwent a composite revascularization procedure utilizing a 'U'-shaped skin incision encircling the parietal branch of the superficial temporal artery (STA) at our institution from 2018 to 2023. We identified the STA parietal branch, MMA, DTA, and MTA in the TOF source MR images acquired preoperatively and three and six months after surgery; measured the long and short diameters of each blood vessel; approximated the blood vessel shape as an ellipse, and calculated its cross-sectional area. ResultsThe cross-sectional areas of the MMA, DTA, and MTA involved in indirect revascularization significantly increased compared to presurgery three months after surgery, and this trend continued six months after surgery, but no significant change was observed between three and six months after surgery. There were no cases in which the MTA was clearly confirmed before surgery in the TOF reconstructed images, but the MTA was clearly confirmed in 55% (11/20 cases) of hemispheres three months after surgery and in 85% (17/20 cases) of hemispheres six months after surgery. The crosssectional area of the STA parietal branch, which was the donor for direct revascularization, had increased by more than 150% compared to before surgery in 55% (11/20 cases) of hemispheres three months after surgery. ConclusionsIndirect revascularization can be expected three months after combined revascularization surgery for moyamoya disease. The MTA, which has not received much attention in terms of indirect revascularization for moyamoya disease patients thus far, was found to be a useful blood flow source for indirect revascularization in combined revascularization surgery for patients with moyamoya disease. Whether or not the cross-sectional area of the superficial temporal artery used as a donor for direct revascularization increased in the medium to long term varied on a case-by-case basis.

Long-term Outcomes of Combined Revascularization Surgery for Moyamoya Disease in the Elderly: A Single Institute Experience.

The opportunity to treat older patients with Moyamoya disease (MMD) is increasing. However, the surgical outcomes after combined direct and indirect revascularization for elderly patients with MMD are not fully understood, especially for those ≥60 years old. This retrospective study examined 232 consecutive hemispheres of 165 adults with MMD who underwent combined revascularization. Clinical features and surgical outcomes were compared between the elderly (≥60 years) and nonelderly group (<60 years). Thirteen (5.6%, 64.4 ± 4.0 years old) and 219 hemispheres (94.4%, 40.2 ± 10.8 years old) were included in the elderly and nonelderly group, respectively. The proportion of clinical presentations before surgery did not differ. However, the prevalence of hypertension and hyperlipidemia was significantly higher in the elderly group than in the nonelderly group. Meanwhile, hyperthyroidism was observed only in the nonelderly group. No significant intergroup differences were observed in the incidence of perioperative complications occurring within four weeks postsurgery. Notably, the elderly group was more prone to develop perioperative intracerebral hemorrhage (odds ratio (OR) 3.14, 95% confidence interval (CI) 0.45-13.5) than the nonelderly group. During a median follow-up period of 7.8 years, the incidence of stroke recurrence occurring later than four weeks postsurgery was not significantly different between the groups (hazard ratio, 1.19; 95% CI 0.133-10.6). The prevalence of independent outcomes (76.9% vs. 90.4%, P = 0.14) and mortality (7.7% vs. 1.4%, P = 0.21) did not differ significantly between the elderly and nonelderly groups, respectively. Perioperative intracerebral hemorrhage may be common in the elderly and should be considered to achieve a favorable surgical outcome.

Risk Factors for Specific Postoperative Ischemic Complications in Patients with Moyamoya Disease: A Single-Center Retrospective Study.

To evaluate and compare postoperative ischemic complications to determine the risk factors for ischemic complications following revascularization surgery for Moyamoya disease (MMD). This single-center retrospective study included 266 procedures between 2016 and 2021. Three types of revascularization approaches including direct bypass, indirect bypass, and combined bypass were performed. To identify risk factors for postoperative ischemic complications and contralateral cerebral infarction, preoperative clinical characteristics and radiographic features were examined using multivariate and ordinal logistic regression analyses. Postoperative ischemic complications occurred in 103 (6.6%) procedures. Ischemic presentation (p=0.001, odds ratios [OR] 5.59, 95% confidence interval [CI] 2.05-15.23), hypertension (p=0.030, OR 2.75, 95%CI 1.11- 6.83), advanced Suzuki stage (p=0.006, OR 3.19, 95%CI 1.40-7.26), and collateral circulation (p=0.001 OR 0.17, 95%CI 0.06-0.47) were risk factors for postoperative ischemic complications. Ordinal regression analysis revealed that unilateral involvement (p=0.043, OR 2.70, 95%CI 0.09-5.31), hemorrhagic presentation (p=0.013, OR 3.45, 95%CI 0.72-6.18), surgical approach (p=0.032, OR -1.38, 95%CI -2.65, -0.12), and collateral circulation [p=0.043, OR -1 .27, 95%CI -2.51, -0.04)] were associated with the type of ischemic complications. History of hypertension (p=0.031) and contralateral computed tomography (CT) perfusion stage (p=0.045) were associated with contralateral infarction. Inability of cerebral vessels to withstand changes in blood pressure induced by revascularization-related hemodynamic instability might be associated with postoperative complications in patients with Moyamoya disease.

Characteristics of donor vessels and cerebral blood flow in the chronic phase after combined revascularization surgery for moyamoya disease

ObjectiveThis study aimed to analyze whether the development of donor vessels after combined revascularization surgery for moyamoya disease (MMD) is related to cerebral blood flow (CBF) changes. MethodsWe retrospectively reviewed the charts of 11 adult (12 hemispheres) and 13 pediatric (19 hemispheres) patients who underwent combined revascularization in our department. The total vessel cross-sectional area (TVA) was the sum of the cross-sectional areas of the superficial temporal, middle meningeal, and deep temporal arteries imaged using time-of-flight magnetic resonance angiography. The ipsilateral relative CBF (RCBF) on the brain surface in the craniotomy area was calculated by single-photon emission computed tomography. ΔTVA and ΔRCBF were defined as the preoperative and postoperative ratios of TVA and RCBF, and their correlations were analyzed in adult and pediatric patients. ResultsThe TVA and RCBF showed a significant increase after surgery, regardless of the age group. However, there was no significant correlation between ΔTVA and ΔRCBF in either the adult or pediatric groups. While the adult group exhibited significantly higher ΔRCBF values compared to the pediatric group (p < 0.01, r = −0.44), the ΔTVA values were higher in the pediatric group compared to the adult group (p = 0.06). ConclusionsIn the chronic phase after combined revascularization surgery for MMD, the development of measurable TVA of donor vessels does not necessarily correlate with an increase in CBF around the craniotomy area.

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

BACKGROUND AND OBJECTIVES: The choice between inhalational and total intravenous anesthesia (TIVA) in revascularization surgery for Moyamoya disease (MMD) remains a topic of debate. Anesthesia methods have changed with the advent of new anesthetics. This study investigated whether modern anesthesia methods affected the development of neurological symptoms after revascularization surgery for MMD. METHODS: This single-center retrospective study included 63 adult patients (82 hemispheres) with MMD treated with direct and indirect bypass surgeries at our hospital between 2013 and 2022. Patients were divided into inhalational anesthesia (IA) and TIVA groups based on the anesthesia maintenance method. Baseline patient characteristics; postoperative neurological symptoms, including hyperperfusion syndrome, cerebral infarction, and transient neurological events (TNEs); and cortical hyperintensity belt (CHB) sign scores (5-point scale from 0 to 4) on postoperative magnetic resonance imaging were compared between the two groups. The operation methods, anesthetics, and intraoperative hemodynamic and ventilatory parameters were compared between patients with and without TNEs. RESULTS: The IA and TIVA groups comprised 39 and 43 hemispheres, respectively. The frequency of postoperative hyperperfusion syndrome and cerebral infarction did not differ between the groups, but the number of TNEs in the IA group (5/39; 13%) was significantly lower than that in the TIVA group (16/43; 37%). Multivariate logistic regression analysis revealed that TNEs were associated with TIVA (odds ratio, 3.91; 95% CI, 1.24-12.35; P = .02). The median [IQR] postoperative CHB sign score in the IA group (2 [1-3]) was significantly lower than that in the TIVA group (4 [3-4]). CONCLUSION: The IA group had fewer postoperative TNEs and lower CHB sign scores than the TIVA group. Although further studies are needed, this study provides insights into the prevention of TNEs with IA and reconsideration of the optimal anesthesia for MMD.

ASL-MRI-guided evaluation of multiple burr hole revascularization surgery in Moyamoya disease

PurposeMoyamoya (MM) disease is characterized by progressive intracranial arterial stenosis. Patients commonly need revascularization surgery to optimize cerebral blood flow (CBF). Estimation of CBF and cerebrovascular reserve (CVR) is therefore necessary before and after surgery. However, assessment of CBF before and after indirect revascularization surgery with the multiple burr hole (MBH) technique in MM has not been studied extensively. In this study, we describe our initial experience using arterial spin labeling magnetic resonance perfusion imaging (ASL-MRI) for CBF and CVR assessment before and after indirect MBH revascularization surgery in MM patients.MethodsEleven MM patients (initial age 6–50 years, 1 male/10 female) with 19 affected hemispheres were included. A total of 35 ASL-MRI examinations were performed using a 3D-pCASL acquisition before and after i.v. acetazolamide challenge (1000 mg in adults and 10 mg/kg in children). Twelve MBH procedures were performed in seven patients. The first follow-up ASL-MRI was performed 7–21 (mean 12) months after surgery.ResultsBefore surgery, CBF was 46 ± 16 (mean ± SD) ml/100 g/min and CVR after acetazolamide challenge was 38.5 ± 9.9 (mean ± SD)% in the most affected territory (middle cerebral artery). In cases in which surgery was not performed, CVR was 56 ± 12 (mean ± SD)% in affected hemispheres. After MBH surgery, there was a relative change in CVR compared to baseline (preop) of + 23.5 ± 23.3% (mean ± SD). There were no new ischemic events.ConclusionUsing ASL-MRI we followed changes in CBF and CVR in patients with MM. The technique was encouraging for assessments before and after revascularization surgery.

Association of RNF213 polymorphism and cortical hyperintensity sign on fluid-attenuated inversion recovery images after revascularization surgery for moyamoya disease: possible involvement of intrinsic vascular vulnerability.

A cortical hyperintensity on fluid-attenuated inversion recovery images (FLAIR cortical hyperintensity (FCH)) is an abnormal finding after revascularization surgery for moyamoya disease. This study aimed to investigate the pathophysiology of FCH through genetic analyses of RNF213 p.R4810K polymorphism and perioperative hemodynamic studies using single-photon emission computed tomography. We studied 96 hemispheres in 65 adults and 47 hemispheres in 27 children, who underwent combined direct and indirect revascularization. Early or late FCH was defined when it was observed on postoperative days 0-2 and 6-9, respectively. FCH scores (range: 0-6) were evaluated according to the extent of FCH in the operated hemisphere. FCHs were significantly more prevalent in adult patients than pediatric patients (early: 94% vs. 78%; late: 97% vs. 59%). In pediatric patients, FCH scores were significantly improved from the early to late phase regardless of the RNF213 genotype (mutant median [IQR]: 2 [1-5] vs. 1 [0-2]; wild-type median: 4 [0.5-6] vs. 0.5 [0-1.75]). In adults, FCH scores were significantly improved in patients with the wild-type RNF213 allele (median: 4 [2-5.25] vs. 2 [2, 3]); however, they showed no significant improvement in patients with the RNF213 mutation. FCH scores were significantly higher in patients with symptomatic cerebral hyperperfusion than those without it (early median: 5 [4, 5] vs. 4 [2-5]; late median: 4 [3-5] vs. 3 [2-4]). In conclusion, the RNF213 p.R4810K polymorphism was associated with prolonged FCH, and extensive FCH was associated with symptomatic cerebral hyperperfusion in adult patients with moyamoya disease.

Impact of craniotomy area on improvement of cerebral blood flow in combined revascularization surgery for moyamoya disease

To investigate factors associated with improvements in cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) after combined revascularization surgery for moyamoya disease, with special attention to the size of craniotomy. We retrospectively analyzed 35 hemispheres in 27 patients with adult and older pediatric moyamoya disease. CBF and CVR were measured separately in the MCA and ACA territories from acetazolamide-challenged single-photon emission computed tomography before and after 6 months postoperatively, and associations with various factors were analyzed. Postoperative CBF improved in patients with lower preoperative blood flow in both ACA and MCA territories. Postoperative CVR improved in 32 of 35 patients (91.4%) in the MCA territory and in 30 of 35 patients (85.7%) in the ACA territory, with more prominent improvement in the MCA territory than in the ACA territory (MCA territory 29.7% vs ACA territory 21.1%, p=0.015). Craniotomy area did not correlate with postoperative CBF and only MCA territory was associated with good (≥30%) CVR improvement (odds ratio 9.33, 95% confidence interval 1.91-45.6, p=0.003). Postoperative CBF improved in adult and older pediatric cases, reflecting preoperative CBF. Postoperative CVR improved in most cases, although the degree of improvement was more prominent in the MCA territory than in the ACA territory, suggesting a contribution of the temporal muscle. Large craniotomy area was not associated with improved blood flow in the ACA territory and should be applied prudently.

Temperature measurement of intracranial cerebrospinal fluid using diffusion tensor imaging after revascularization surgery in Moyamoya disease

ObjectiveBrain temperature monitoring using a catheter thermometer has been reported to be a useful technique to predict prognosis in neurosurgery. To investigate the possibility of measuring intracranial cerebrospinal fluid temperature for postoperative monitoring in patients with Moyamoya disease (MMD) after bypass surgery. Materials and methodsThis study evaluated fifteen patients with MMD who were indicated for bypass surgery. Diffusion tensor imaging for brain thermometry were performed on a 1.5-T MR scanner. Intracranial cerebrospinal fluid temperature with/without considering the fractional anisotropy component, body temperature, C-reactive protein levels, white blood cell count, and cerebral blood flow measured by 123I-IMP single-photon emission computed tomography were obtained before surgery and 1–3 days after surgery. Pixel values considered to be signal outliers in fractional anisotropy processing were defined as cerebrospinal fluid noise index and calculated. Wilcoxon signed-rank test and effect size were performed to compare the changes before and after revascularization. Spearman's rho correlation coefficient was used to analyze the correlations between each parameter. Statistical significance was defined as p < 0.05. ResultsAll parameter values became significantly higher compared to those measured before revascularization (p < 0.01 in all cases). The effect sizes were largest for the cerebrospinal fluid temperature with fractional anisotropy processing and for C-reactive protein levels (Rank-biserial correlation = 1.0). The cerebrospinal fluid noise index and cerebrospinal fluid temperatures with fractional anisotropy processing (r = 0.84, p < 0.0001) or without fractional anisotropy processing (r = 0.95, p < 0.0001) showed highly significant positive correlations. Although no significant correlation was observed, cerebrospinal fluid temperatures with fractional anisotropy had small or moderately positive correlations with cerebral blood flow, body temperature, C-reactive protein levels, and white blood cell count (r = 0.37, 0.42, 0.41, and 0.44, respectively; p > 0.05). ConclusionOur findings suggest the possibility of postoperative monitoring for MMD patients by measuring intracranial cerebrospinal fluid temperature with fractional anisotropy processing. Intracranial cerebrospinal fluid temperature might be considered as combined response since cerebrospinal fluid, body temperature, and inflammation are equally correlated.

Postoperative cerebral infarction after revascularization in patients with moyamoya disease: Incidence and risk factors.

Cerebral infarction is the major complication of revascularization surgery in patients with moyamoya disease (MMD), and we analyzed the possible causes of cerebral infarction after revascularization surgery for MMD. MMD patients who were admitted and underwent surgical revascularization at Shanghai Huashan Hospital from January 2019 to December 2021 were retrospectively analyzed. A total of 815 patients and 890 revascularization surgeries (677 first revascularization surgeries and 213 second revascularization surgeries) were included in this study; 453 (50.9%) were performed on the left side and 437 (49.1%) on the right side, with 779 (87.5%) combined procedures and 111 (12.5%) indirect bypasses included. The mean patient age at the time of these procedures was 44.6 ± 11.7 years (range 6-72 years). Postoperative cerebral infarctions were observed in 46 (5.17%) surgeries, among which 31 occurred after left hemisphere revascularization surgeries, with an incidence of 6.84%, and 15 occurred after right hemisphere revascularization surgeries, with an incidence of 3.43%. Of these, 30 (65.2%) occurred in the operated hemispheres, 2 (4.3%) in the contralateral hemisphere and 13 (28.3%) in the bilateral hemisphere. There were 11 cases of massive infarction (23.9%). The incidence of postoperative infarction in patients undergoing the first revascularization was 6% (41/677) and 2.3% (5/213) in the second revascularization surgeries. Initial presentation as infarction (P < 0.001), initial presentation as hemorrhage (P < 0.001), hypertension (P = 0.018), diabetes (P = 0.006), 1st or 2nd surgery and surgical side (P = 0.007) were found to be related to postoperative cerebral infarction. Initial presentation as infarction (OR = 2.934, 95% CI 1.453-5.928, P = 0.003), initial presentation as hemorrhage (OR = 0.149, 95% CI 0.035-0.641, P = 0.011), and 1st or 2nd surgery and surgical side (OR = 1.66, 95% CI 1.106-2.491, P = 0.014) were independently associated with cerebral infarction after revascularization surgeries. In patients with MMD undergoing surgical revascularization, initial presentation as infarction and first revascularization surgery performed on the left hemisphere are independent risk factors for postoperative cerebral infarction, whereas initial presentation as hemorrhage is a protective factor.

Effect of combined Japanese traditional medicines, keishibukuryogan and jidabokuippo, on postoperative soft tissue swelling in adult patients undergoing revascularization surgery for ischemic moyamoya disease: A comparison of two prospective cohort studies

AbstractAimIndirect revascularization surgery for moyamoya disease (MMD) sometimes results in swelling of the soft tissues (including the temporalis muscle) compressing the cerebral hemispheres postoperatively. The present supplementary analysis of two prospective cohorts aimed to elucidate the effects of Japanese traditional medicines, keishibukuryogan and jidabokuippo, on postoperative soft tissue swelling in adult patients undergoing revascularization surgery for ischemic MMD.MethodsThirty‐two patients treated using direct revascularization surgery alone without Japanese traditional medicine (the first original study) and another 22 patients treated using indirect revascularization surgery alone with perioperative administration of keishibukuryogan and jidabokuippo (the second original study) underwent computed tomography of the head before and 3 days after surgery. The postoperative swelling rate of soft tissues in the head ipsilateral to the surgery was calculated.ResultsThe postoperative swelling rate of the soft tissues was significantly lower in patients participating in the second original study (88.8 ± 31.6%) than in those participating in the first original study (127.1 ± 31.1%) (p = 0.0002). When postoperative swelling rates of soft tissues in all 54 patients were arranged in descending order and divided into tertiles (186.7–132.0%, 130.0–92.4%, 92.3–44.3%), logistic regression analysis revealed that participation in the second original study was significantly associated with the bottom tertile of postoperative swelling rate of soft tissues (95% confidence interval, 4.90–100.12; p = 0.0098).ConclusionCombined administration of Japanese traditional medicines, keishibukuryogan and jidabokuippo, can reduce postoperative soft tissue swelling in adult patients undergoing revascularization surgery for ischemic MMD.

Preoperative Brain Functional Connectivity Improve Predictive Accuracy of Outcomes After Revascularization in Moyamoya Disease.

In patients with moyamoya disease (MMD), focal impairments in cerebral hemodynamics are often inconsistent with patients' clinical prognoses. Evaluation of entire brain functional networks may enable predicting MMD outcomes after revascularization. To investigate whether preoperative brain functional connectivity could predict outcomes after revascularization in MMD. We included 34 patients with MMD who underwent preoperative MRI scanning and combined revascularization surgery. We used region of interest analyses to explore the differences in functional connectivity for 90 paired brain regions between patients who had favorable outcomes 1 year after surgery (no recurrent stroke, with improved preoperative symptoms, or modified Rankin Scale [mRS]) and those who had unimproved outcomes (recurrent stroke, persistent symptoms, or declined mRS). Variables, including age, body mass index, mRS at admission, Suzuki stage, posterior cerebral artery involvement, and functional connectivity with significant differences between the groups, were included in the discriminant function analysis to predict patient outcomes. Functional connectivity between posterior cingulate cortex and paracentral lobule within the right hemisphere, and interhemispheric connection between superior parietal gyrus and middle frontal gyrus, precuneus and middle cingulate cortex, cuneus and precuneus, differed significantly between the groups (P < .001, false discovery rate corrected) and had the greatest discriminant function in the prediction model. Although clinical characteristics of patients with MMD showed great accuracy in predicting outcomes (64.7%), adding information on functional connections improved accuracy to 91.2%. Preoperative functional connectivity derived from rs-fMRI may be an early hallmark for predicting patients' prognosis after revascularization surgery for MMD.

Cerebrovascular Reserve Impairment in the Anterior Cerebral Artery Territory Predicts Deep Temporal Artery Enlargement After Combined Revascularization Surgery in Moyamoya Disease.

A combined surgery of direct and indirect revascularization has been frequently performed in patients with moyamoya disease, though the efficacy of indirect revascularization surgery in adult patients with moyamoya disease has not been established. This study aimed to evaluate superficial temporal artery (STA) and deep temporal artery (DTA) diameters 1day and 3months after combined revascularization surgery in patients with moyamoya disease. We also investigated clinical factors related to DTA enlargement after surgery. We examined 78 cerebral hemispheres in 57 adult and pediatric patients with moyamoya disease who underwent combined revascularization surgery [STA-MCA bypass and encephalo-duro-myo-synangiosis] in our institution. STA and DTA diameters were measured on axial magnetic resonance angiography images at 1day and 3months after surgery. DTA diameter increased in 64 hemispheres (82.1%). DTA diameter increase in association with STA diameter decrease was found in 39 hemispheres (50%). The proportion of hemispheres with a reduction in STA diameter was significantly higher in hemispheres with DTA enlargement than in hemispheres with DTA reduction (P=0.0088). Among the 64 hemispheres with DTA enlargement, 51 (79.7%) showed cerebrovascular reserve (CVR) impairment in the anterior cerebral artery (ACA) territory before surgery. CVR impairment in the ACA territory was the only clinical factor related to DTA enlargement (P<0.001). The DTA frequently enlarges after combined revascularization surgery, even in adult patients with moyamoya disease. In patients with impaired CVR in the ACA territory, blood supply from the DTA to the ACA territory can be expected after combined revascularization surgery.

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

Cerebral angiography is the gold standard for diagnosing moyamoya disease (MMD), whereas magnetic resonance (MR) imaging/angiography is becoming more popular in the field of cerebrovascular disease due to its low invasiveness. Although there are concerns about using only MR imaging/angiography for preoperative analysis of MMD, considering the underestimation of pre-existing transdural collateral circulations and dangerous collaterals related to the risk of hemorrhage, we retrospectively reviewed our 10-year experience of MR imaging-first diagnosis and analyzed the perioperative outcomes. We analyzed 160 consecutive direct/indirect combined revascularization procedures for MMD preoperatively assessed using MR imaging/angiography alone. Perioperative complications were assessed for up to 2weeks after surgery. Locations of the lesions responsible for complications were further classified into the surgical field, the ipsilateral hemisphere outside the surgical field, and the contralateral hemisphere. Sixty-four revascularization procedures were performed in 38 children, and 96 procedures were performed in 68 adults. There was no difference in the incidence of perioperative ischemic complications between adults (6.3%) and pediatric patients (4.7%), but hemorrhagic complications were more frequently observed in adults (7.3%) than in children (0%) (P < 0.05). There was no specific lesion deviation for ischemic complications; however, hemorrhagic complications predominantly occurred in the surgical field. Direct/indirect combined revascularization surgery based on our preoperative diagnostic protocol with the MR-first strategy resulted in favorable outcomes in pediatric MMD patients with relatively low complication rates. However, the validity of the MR-first diagnostic protocol should be further evaluated in adult patients with MMD.

Bilateral Improvement of Cerebrovascular Reserve Following Unilateral Revascularization Surgery in Moyamoya Disease: A Case Report

Bilateral Improvement of Cerebrovascular Reserve Following Unilateral Revascularization Surgery in Moyamoya Disease: A Case Report

The First 24 h Hemodynamic Management in NICU after Revascularization Surgery in Moyamoya Disease.

Objective To evaluate whether hemodynamic factors are risk factors for prognosis in moyamoya disease (MMD). Materials and Methods The retrospective study reviewed a single-center MMD cohort in Huashan Hospital from August 2017 to January 2020. Stroke events in 30 days and follow-up modified Rankin Scale (mRS) grade were recorded. Systematic assessments with perioperative mean arterial pressure (MAP), red blood cell (RBC) parameters, and fluid management were also conducted. Logistic regressions were applied to evaluate the predictors of worse outcomes. Data was analyzed using SPSS 24.0. Results Admission to neurological intensive care unit (NICU) totalled about 347 after revascularization surgery. The result showed that the higher the postoperative MAP level (favorable group 95.7 ± 11.4 mmHg vs. unfavorable group 103.6 ± 10.4 mmHg, p < 0.001) and the greater the MAP variability (favorable group 0.26 ± 13.2 vs. unfavorable group 7.2 ± 13.5, p = 0.006) were, the higher the patient's follow-up mRS grade was. What is more, a higher early postoperative Hb level also seemed to predict a worse long-term clinical outcome (favorable group 116.9 ± 17.1 g/L vs. unfavorable group 123.7 ± 13.0 g/L, p = 0.03), but the difference disappeared after adjusting sex and age. Logistic regression analyses showed that a higher level of postoperative MAP (β = 0.024, 95% CI (0.004, 0.044), and p = 0.02) within the first 24 h in NICU might be the short-term risk factor. For long-term outcome, a higher level (β = 1.058, 95% CI (1.022, 1.096), and p = 0.001) and a greater variability (β = 30.982, 95% CI (2.112, 454.414), and p = 0.01) of postoperative MAP might be the negative predictors of mRS grade. Conclusions The early postoperative hemodynamic management might be extremely critical for patients with MMD. Both high postoperative MAP levels and large MAP variability might affect the prognosis. What is more, we also found that a higher postoperative Hb level might be related with a worse outcome.

Late morbidity and mortality following revascularization surgery for moyamoya disease in the pediatric population.

There are limited reports on long-term morbidity in pediatric patients who have undergone surgical revascularization for moyamoya disease (MMD). Here, the authors report long-term morbidity and mortality in a population of pediatric patients who underwent pial synangiosis for MMD from 1988 through 2016. A single-center retrospective review of the hospital and personal operative databases of the senior authors was carried out to identify all patients who were treated for MMD at Boston Children's Hospital between 1988 and 2016, and who experienced any episode of late morbidity or mortality, which the authors defined as an event resulting in significant neurological deficit or death occurring more than 1 year after revascularization surgery. Hospital records were reviewed to determine pertinent demographic data, the initial mode of patient presentation, and associated comorbidities. Radiographic studies, when available, were reviewed for documentation of the diagnosis and for confirmation of the late complication, and the literature on this topic was reviewed. In total, 460 patients with MMD underwent surgery between 1988 and 2016 using the pial synangiosis surgical technique; 15 (3.3%) of these patients (9 females and 6 males) experienced documented late death (n = 14) or severe morbidity (n = 1). The median age at revascularization surgery was 8.0 years (range 1-21 years). The causes of these late complications were grouped into three etiologies: intraventricular or intracerebral hemorrhage (n = 8), systemic complications related to associated comorbidities or preoperative disabilities (n = 5), and the development of malignant brain tumors (n = 2). Four patients whose MMD was associated with a history of cranial radiation therapy died. These events occurred from as early as 2 years to as late as 27 years postoperatively. The risk of late morbidities and mortality following pial synangiosis for MMD in the pediatric patient appeared to be low. Nevertheless, the occurrence of catastrophic cerebrovascular events, particularly intracerebral and intraventricular hemorrhage in the otherwise neurologically stable revascularized patient, was concerning. Although there is value in long-term surveillance of patients who have undergone surgery for MMD, from both a neurological and a general medical standpoint, particularly in patients with the risk factor of prior cranial radiation therapy, it is not clear from the data how the late deaths in this population could have been prevented.