A critical appraisal of bypass surgery in moyamoya disease

Prediction of cerebral infarction after bypass surgery in adult moyamoya disease: using pulsatility index on TCD

BACKGROUND

At present, the most effective treatment for symptomatic moyamoya disease (MMD) is surgery. However, the high incidence of postoperative complications is a serious problem plaguing the surgical treatment of MMD, especially the acute cerebral infarction. Decreased cerebrovascular reserve is an independent risk factor for ischemic infarction, and the pulsatility index (PI) of transcranial Doppler (TCD) is a common intuitive index for evaluating intracranial vascular compliance. However, the relationship between PI and the occurrence of ischemic stroke after operation is unclear.

OBJECTIVE

To explore whether the PI in the middle cerebral artery (MCA) could serve as a potential predictor for the occurrence of ischemic infarction after bypass surgery in MMD.

METHODS

We performed a retrospective analysis of data from 71 patients who underwent combined revascularization surgery, including superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis and encephalo-duro-myo-synangiosis (EDMS). The patients were divided into two groups according to the median of ipsilateral MCA-PI before operation, low PI group (MCA-PI < 0.614) and high PI group (MCA-PI ≥ 0.614). Univariate and multivariate regression analysis were used to explore risk factors affecting the occurrence of postoperative cerebral infarction.

RESULTS

Among the 71 patients with moyamoya disease, 11 patients had cerebral infarction within one week after revascularization. Among them, 10 patients' ipsilateral MCA-PI were less than 0.614, and another one's MCA- PI is higher than 0.614. Univariate analysis showed that the lower ipsilateral MCA-PI (0.448 ± 0.109 vs. 0.637 ± 0.124; P = 0.001) and higher Suzuki stage (P = 0.025) were linked to postoperative cerebral infarction. Multivariate analysis revealed that lower ipsilateral MCA-PI was an independent risk factor for predicting postoperative cerebral infarction (adjusted OR = 14.063; 95% CI = 6.265 ~ 37.308; P = 0.009).

CONCLUSIONS

A lower PI in the ipsilateral MCA may predict the cerebral infarction after combined revascularization surgery with high specificity. And combined revascularization appears to be safer for the moyamoya patients in early stages.

[Moyamoya disease in adults: treatment methods in modern era]

Moyamoya angiopathy is a chronic progressive cerebrovascular disease characterized by stenosis and occlusion of the distal segments of the internal carotid arteries and/or proximal segments of the middle and anterior cerebral arteries, with a gradual compensatory restructuring of the cerebral circulation to the system of the external carotid arteries. Today, the main treatment method for Moyamoya angiopathy is surgical revascularization of the brain. A search and analysis of publications on the treatment of adult patients with Moyamoya angiopathy was carried out in the PubMed and Medscape databases over the past 10 years. We present a case of an adult female patient with a hemorrhagic form of Moyamoya angiopathy stage IV according to J. Suzuki, who underwent staged combined revascularization of both cerebral hemispheres. Surgical revascularization included the creation of a low-flow extra-intracranial shunt combined with a combination of indirect synangiosis. The combination of direct and indirect methods of surgical revascularization enables to achieve the development of an extensive network of collaterals and fully compensate for cerebral circulatory disorders both in the early and late postoperative periods, which is confirmed by instrumental diagnostic data. Combined revascularization is the most effective modern method of treating patients with Moyamoya angiopathy due to the complementary influence of direct and indirect components of revascularization.

Local transplantation of mesenchymal stem cells improves encephalo-myo-synangiosis-mediated collateral neovascularization in chronic brain ischemia

BACKGROUND

To explore whether local transplantation of mesenchymal stem cells (MSCs) in temporal muscle can promote collateral angiogenesis and to analyze its main mechanisms of promoting angiogenesis.

METHODS

Bilateral carotid artery stenosis (BCAS) treated mice were administrated with encephalo-myo-synangiosis (EMS), and bone marrow mesenchymal stem cells (BMSCs) were transplanted into the temporal muscle near the cerebral cortex. On the 30th day after EMS, the Morris water maze, immunofluorescence, laser speckle imaging, and light sheet microscopy were performed to evaluate angiogenesis; In addition, rats with bilateral common carotid artery occlusion were also followed by EMS surgery, and BMSCs from GFP reporter rats were transplanted into the temporal muscle to observe the survival time of BMSCs. Then, the concentrated BMSC-derived conditioned medium (BMSC-CM) was used to stimulate HUVECs and BMECs for ki-67 immunocytochemistry, CCK-8, transwell and chick chorioallantoic membrane assays. Finally, the cortical tissue near the temporal muscle was extracted after EMS, and proteome profiler (angiogenesis array) as well as RT-qPCR of mRNA or miRNA was performed.

RESULTS

The results of the Morris water maze 30 days after BMSC transplantation in BCAS mice during the EMS operation, showed that the cognitive impairment in the BCAS + EMS + BMSC group was alleviated (P < 0.05). The results of immunofluorescence, laser speckle imaging, and light sheet microscopy showed that the number of blood vessels, blood flow and astrocytes increased in the BCAS + EMS + BMSC group (P < 0.05). The BMSCs of GFP reporter rats were applied to EMS and showed that the transplanted BMSCs could survive for up to 14 days. Then, the results of ki-67 immunocytochemistry, CCK-8 and transwell assays showed that the concentrated BMSC-CM could promote the proliferation and migration of HUVECs and BMECs (P < 0.05). Finally, the results of proteome profiler (angiogenesis array) in the cerebral cortex showed that the several pro-angiogenesis factors (such as MMP-3, MMP-9, IGFBP-2 or IGFBP-3) were notably highly expressed in MSC transplantation group compared to others.

CONCLUSIONS

Local MSCs transplantation together with EMS surgery can promote angiogenesis and cognitive behavior in chronic brain ischemia mice. Our study illustrated that MSC local transplantation can be the potential therapeutical option for improving EMS treatment efficiency which might be translated into clinical application.

Clinical Efficacy of Superficial Temporal Artery-middle Cerebral Artery Bypass Grafting Surgery Combined With Temporal Muscle Patch on Patients With Moyamoya Disease

OBJECTIVE

To analyze the clinical efficacy of superficial temporal artery-middle cerebral artery (STA-MCA) bypass grafting surgery combined with temporal muscle patch and STA-MCA bypass grafting surgery alone on patients with moyamoya disease.

METHODS

Totally 73 patients confirmed with moyamoya disease in our hospital between January 2019 and December 2021 were enrolled. Among them, 43 patients treated with STA-MCA bypass grafting surgery combined with temporal muscle patch were assigned to the experiment group, whereas 30 patients treated with STA-MCA bypass grafting surgery alone to the control group. The following items of the 2 groups were compared: clinical efficacy, total effective rate, and disease control rate 6 months after surgery, the changes of modified Rankin Scale (mRS) and Karnofsky performance scale (KPS) scores before and on the seventh day and 6 months after surgery, and changes of Glasgow coma scale scores before and 24 hours after surgery. In addition, the incidences of cerebral ischemia and cerebral hemorrhage within 1 year after surgery were counted. The cerebral perfusion-associated indexes including relative mean transit time (rMTT), relative time-to-peak, relative cerebral blood flow (rCBF), and relative cerebral blood volume (rCBV) on the seventh day and 6 months after surgery were compared between the 2 groups, and the predictive value of cerebral perfusion-associated indexes before surgery for clinical efficacy on patients was analyzed.

RESULTS

The Glasgow coma scale score after surgery ( P >0.05) was similar between the 2 groups, but the clinical efficacy and total effective rate of the 2 groups were notably different (both P <0.05). Compared with those before surgery, mRS scores of both groups declined, whereas KPS scores increased (both P <0.05) on the seventh day after surgery. In addition, compared with those before surgery and on the seventh day after surgery, mRS scores of both groups decreased 6 months after surgery, whereas KPS scores increased (both P <0.05). Both the groups showed decreased rMTT and rTPP, and increased rCBF and rCBV on the seventh day after surgery than those before surgery (all P <0.05). In addition, both the groups still showed decreased rMTT and rTPP, and increased rCBF and rCBV 6 months after surgery than those before surgery and on the seventh day after surgery (all P <0.05). Most notably, the experimental group displayed improved cerebral perfusion-associated indexes than the control group 6 months after surgery (all P <0.05). The relief group showed notably higher rCBF and rCBV levels than the nonrelief group (both P <0.05). According to ROC analysis, the areas under the curves of rCBF and rCBV in forecasting the clinical efficacy on patients were 0.842 and 0.823, respectively.

CONCLUSION

Superficial temporal artery-middle cerebral artery bypass grafting surgery combined with temporal muscle patch can deliver a higher total clinical curative rate for patients with moyamoya disease and can alleviate their coma.

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

OBJECTIVES

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.

METHODS

MMD patients who were admitted and underwent surgical revascularization at Shanghai Huashan Hospital from January 2019 to December 2021 were retrospectively analyzed.

RESULTS

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.

CONCLUSIONS

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.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A meta-analysis of comparisons of various surgical treatments for moyamoya diseases

PURPOSE

Ischemia is one of the most familiar complications in the different procedures for moyamoya disease (MMD), but the optimal surgical approaches for MMD remain unknown. We aimed to evaluate the efficiency of various surgical treatments.

METHODS

A literature search word was performed through four databases such as Cochrane Library, Web of Science, PubMed, and EMBASE for the literature published until May 2021. The I² statistic was used to assess heterogeneity. A random/fixed-effects model was used to pool.

RESULTS

There are a total of 18 studies including three surgical treatments such as including indirect, direct, and combined bypass in this study. The result revealed that indirect bypass was related to a higher incidence of recurrence stroke compared to the direct and combined bypass treatment (p = .001). Furthermore, the cases undergoing direct bypass were associated with a better angiographic change than the indirect bypass (OR = 3.254, p = .013).

CONCLUSION

This meta-analysis demonstrated a positive effect of using the direct and combined bypass to treat MMD compared to indirect bypass due to their lower rates of recurrence stroke.

Use of a panel of four microRNAs in CSF as a predicted biomarker for postoperative neoangiogenesis in moyamoya disease

INTRODUCTION AND AIMS

At present, the treatment for moyamoya disease (MMD) primarily consists of combined direct and indirect bypass surgery. Nevertheless, more than half of indirect bypass surgeries fail to develop good collaterals from the dura and temporal muscle. This study aimed to investigate whether microRNAs (miRNAs) in cerebrospinal fluid (CSF) could serve as biomarkers for the prediction of postoperative collateral formation.

METHODS

Moyamoya disease patients with indirect bypass surgery were divided into angiogenesis and non-angiogenesis groups, CSF was obtained, and miRNA sequencing was performed using the CSF. Candidate miRNAs were filtered and subsequently verified through qRT-PCR. The diagnostic utility of these differential miRNAs was investigated by using receiver operating characteristic (ROC) curve analysis. Finally, the potential biological processes and signaling pathways associated with candidate miRNAs were analyzed using R software.

RESULTS

The expression levels of four miRNAs (miR-92a-3p, miR-486-3p, miR-25-3p, and miR-155-5p) were significantly increased in the angiogenesis group. By combining these four miRNAs (area under the curve [AUC] =0.970), we established an accurate predictive model of collateral circulation after indirect bypass surgery in MMD patients. GO and KEGG analyses demonstrated a high correlation with biological processes and signaling pathways related to angiogenesis.

CONCLUSION

The 4-miRNA signature is a good model to predict angiogenesis after indirect bypass surgery and help the surgeon to select a appreciate bypass strategy.

Moyamoya disease concurrent with dural arteriovenous fistula: A case report and literature review

Moyamoya disease (MMD) and dural arteriovenous fistula (DAVF) are two distinct types of intracranial lesion that share different pathogenic mechanisms. Under rare circumstances, patients with MMD have been reported to have concurrent DAVF. The present case study reports on a 47-year-old male admitted due to sudden headache. Head CT revealed hemorrhage of the right thalamus with ventricular extension. On CT angiography, the normal vasculature in the anterior and posterior circulation disappeared and was replaced by moyamoya-like vessels. The patient received conservative management and was discharged 3 days later. After three months, the patient was readmitted for acute cerebellar hemisphere infarction. Angiogram indicated that the DAVF (Cognard classification Ⅰ) was supplied by the left middle meningeal artery, occipital artery and posterior meningeal artery and drained into the transverse-sigmoid sinus and occipital sinus. Conservative management of the DAVF was adopted. The patient was stable and lived independently during a 4-year follow-up. A literature review of the reported cases was also performed to further characterize this rare entity. The management of DAVF concurrent with MMD depends on its clinical presentation and invasiveness. For patients with symptoms or cortical venous drainage, endovascular intervention should be performed. For asymptomatic DAVFs or those without cerebral venous drainage, close follow-up is a reasonable option.