Recognition of the Effect of Indirect Revascularization for Moyamoya Disease: The Balance Between the Stage Progression and Neoangiogenesis

Encephaloduroarteriosynangiosis for Symptomatic Intracranial Atherosclerotic Arterial Steno-Occlusive Disease: Clinical and Radiological Outcomes

BACKGROUND

This study investigated the long-term clinical and angiographic outcomes of encephaloduroarteriosynangiosis treatment for symptomatic intracranial atherosclerotic arterial steno-occlusive disease to further evaluate the potential therapeutic role of encephaloduroarteriosynangiosis in this population.

METHODS AND RESULTS

A total of 152 adult patients with symptomatic intracranial atherosclerotic arterial steno-occlusive disease who were treated with encephaloduroarteriosynangiosis and intensive medical management across 3 tertiary centers in China between January 2011 and September 2019 were retrospectively included. The primary outcomes were defined as postoperative cerebrovascular events, including ischemic and hemorrhagic stroke. The postoperative neovascularization was analyzed qualitatively and quantitatively by using angiography. Clinical, radiological, and long-term follow-up data were analyzed using Cox regression, logistic regression, and linear regression analyses. Primary outcome rates were 3.2% (5/152) within 30 days, 6.6% (10/152) within 2 years, 9.2% (14/152) within 5 years, and 11.1% (17/152) during a median 9.13 years follow-up. Initial infarction symptoms were positively associated with recurrent ischemic stroke. Additionally, posterior circulation involvement and coexisting cardiac disease indicated poorer neurological status, whereas encephaloduroarteriosynangiosis neovascularization efficacy was negatively associated with older age and vascular risk factors but positively associated with posterior circulation involvement.

CONCLUSIONS

Encephaloduroarteriosynangiosis plus intensive medical management appears efficacious and safe for symptomatic intracranial atherosclerotic arterial steno-occlusive disease, with low perioperative risk and favorable long-term results. Further prospective trials are needed to verify its efficacy and determine the optimal patient selection criteria.

Ultrasonographic Predictors for Post-operative Ischemic Events After Indirect Revascularization Surgeries in Patients with Moyamoya Disease

OBJECTIVE

Recurrent stroke after revascularization surgeries predicts poor outcome in patients with moyamoya disease (MMD). Early identification of patients with stroke risk paves the way for rescue intervention. This study aimed to investigate the role of ultrasound in identifying patients at risk of post-operative ischemic events (PIEs).

METHODS

This prospective study enrolled patients with symptomatic MMD who underwent indirect revascularization surgeries. Ultrasound examinations were performed preoperatively and at 3 mo post-operatively to evaluate the hemodynamic changes in extracranial and intracranial arteries on the operated side. PIE was defined as ischemic stroke or transient ischemic attack in the operated hemisphere within 1 y. The areas under receiver operating characteristic curves were compared between models for prediction of PIE.

RESULTS

A total of 56 operated hemispheres from 36 patients (mean age, 23.0 ± 18.5 y) were enrolled in this study, and 27% developed PIE. In multivariate logistic regression models, PIE was associated with lower end-diastolic velocity and flow volume (FV) of the ipsilateral external carotid artery (ECA), and lower FV of ipsilateral superficial temporal artery and occipital artery at 3 mo post-operatively (all p < 0.05). Moreover, the post-operative FV of the ipsilateral ECA was the only one factor that significantly increased the areas under receiver operating characteristic curves from 0.727 to 0.932 when adding to a clinical-angiographic model for prediction of PIE (p = 0.017). This parameter was significantly lower in hemispheres with PIE, both in adult and pediatric patients.

CONCLUSION

After indirect revascularization, surgeries in patients with symptomatic MMD, FV of ipsilateral ECA at 3 mo helps clinicians to identify patients at risk of PIE.

Clinical and genetic factors associated with contralateral progression in unilateral moyamoya disease: Longitudinal and Cross-Sectional Study

Objective

This study aimed to explore the long-term outcome of unilateral moyamoya disease and predict the clinical and genetic factors associated with contralateral progression in unilateral moyamoya disease.

Methods

We retrospectively recruited unilateral moyamoya disease patients with available genetic data who underwent encephaloduroarteriosynangiosis (EDAS) surgery at our institution from January 2009 to November 2017. Long-term follow-up data, including clinical outcomes, angiographic features, and genetic information, were analyzed.

Results

A total of 83 unilateral moyamoya disease patients with available genetic data were enrolled in our study. The mean duration of clinical follow-up was 7.9 ± 2.0 years. Among all patients, 19 patients demonstrated contralateral progression to bilateral disease. Heterozygous Ring Finger Protein 213 p.R4810K mutations occurred significantly more frequently in unilateral moyamoya disease patients with contralateral progression. Furthermore, patients with contralateral progression typically demonstrated an earlier age of onset than those with non-progressing unilateral moyamoya disease. In the contralateral progression group, posterior circulation involvement was observed in 11 (11/19, 57.9%) patients compared to 12 (12/64, 18.8%) in the non-contralateral progression group (P = 0.001). The time to peak of cerebral perfusion and neurological status showed significant postoperative improvement.

Conclusion

Long-term follow-up revealed that the EDAS procedure might provide benefits for unilateral moyamoya disease patients. Ring Finger Protein 213 p.R4810K mutations, younger age, and posterior circulation involvement might predict the contralateral progression of unilateral moyamoya disease.

Hemodynamics of vascular shunts: trends, challenges, and prospects

Vascular bypass surgery takes a significant place in the treatment of vascular disease. According to various assessments, this type of surgery is associated with almost 20 % of all vascular surgery episodes (up to 23 % according to the Federal Neurosurgical Center of Novosibirsk). Even though the problem of using of vascular grafts is obvious and natural, many problems associated with them are not still elucidated. From the mechanics' point of view, a vascular bypass is a converging or diverging tee, and the functioning of such structures still does not have strict mathematical formulations and proofs in the general case, which forces many researchers to solve specific engineering problems associated with shunting. Mathematical modeling, which is the gold standard for virtual simulations of industrial and medical problems, faces great difficulties and limitations in solving problems for vascular bypasses. Complications in the treatment of the vascular disease may follow the difficulties in mathematical modeling, and the price can be a cardiac arrest or a stroke. This work is devoted to the main aspects of the medical application of vascular bypasses and their functioning as a mechanical system, as well the mathematical aspects of their possible setup.

Factors Influencing Collateral Circulation Formation After Indirect Revascularization for Moyamoya Disease: a Narrative Review

Indirect revascularization is one of the main techniques for the treatment of Moyamoya disease. The formation of good collateral circulation is a key measure to improve cerebral blood perfusion and reduce the risk of secondary stroke, and is the main method for evaluating the effect of indirect revascularization. Therefore, how to predict and promote the formation of collateral circulation before and after surgery is important for improving the success rate of indirect revascularization in Moyamoya disease. Previous studies have shown that vascular endothelial growth factor, endothelial progenitor cells, Caveolin-1, and other factors observed in patients with Moyamoya disease may play a key role in the generation of collateral vessels after indirect revascularization through endothelial hyperplasia and smooth muscle migration. In addition, mutations in the genetic factor RNF213 have also been associated with this process. This study summarizes the factors and mechanisms influencing collateral circulation formation after indirect revascularization in Moyamoya disease.

Transdural Collateral Circulation Indicates Cerebral Ischemia in Moyamoya Disease

BACKGROUND

Moyamoya disease (MMD) is an idiopathic occlusive cerebrovascular disorder. The development of collateral circulation originates from the dural and pial collaterals. Currently, the clinical significance of transdural collateral in MMD has not been established. We sought to study the relationship between transdural collateral circulation and the side of relative cerebral ischemia in MMD.

METHODS

Data from MMD patients were collected at Xiangya Hospital from January 2016 to April 2022. A collateral circulation grading system with scores was established, the dominant side of transdural collateral with a higher point. Cerebral perfusion was used to identify the side of relative cerebral ischemia.

RESULTS

A total of 102 patients were recruited. Results of digital subtraction angiography showed that 74 (72.5%) patients had transdural collaterals. The transdural collaterals were more common in patients with infarctions than in those with headaches or transient ischemic attacks (P = 0.0074). The dominant side for the formation of transdural collateral circulation was more easily found at the side of relative cerebral ischemia (P < 0.0001). Additionally, the side of the brain with a higher score of transdural collaterals was more likely to experience relative cerebral ischemia (P < 0.0001). There was no significant difference in the formation of transdural collateral circulation between ischemic and hemorrhagic MMD patients.

CONCLUSIONS

Transdural collateral circulation was common in MMD patients. The transdural collaterals were associated with the occurrence of infarction. Transdural collaterals were well established on the cerebral ischemic side, which indicated higher ischemic levels in the ipsilateral than contralateral side.

Efficacy of modified EDAS combined with a superficial temporal fascia attachment-dural reversal surgery for the precise treatment of ischemic cerebrovascular disease

Objective

To investigate the potential therapeutic benefits of Modified EDAS combined with superficial temporal fascia attachment-dural reversal surgery for the treatment of ischemic cerebrovascular disease.

Methods

Retrospective analysis was made on the clinical data of 33 patients with ischemic cerebrovascular disease, who were admitted to the Neurological Diagnosis and Treatment Center of the Second Affiliated Hospital of Xinjiang Medical University from December 2019 to June 2021. All patients were treated with Modified EDAS combined with superficial temporal fascia attachment-dural reversal surgery. At 3 months after operation, the outpatient department rechecked the patient's head CT perfusion imaging (CTP) to understand the intracranial cerebral blood flow perfusion. The DSA of the patient's head was re-examined 6 months after operation to observe the establishment of collateral circulation. The improved Rankin Rating Scale (mRS) score was used to evaluate the good prognosis rate of patients at 6 months after surgery. The mRS score ≤2 was defined as good prognosis.

Results

The preoperative cerebral blood flow (CBF), local blood flow peak time (rTTP), and local mean transit time (rMTT) of 33 patients were 28.235 ml/(100 g·min), 17.702 s, 9.796 s, respectively. At 3 months after surgery, CBF, rTTP, and rMTT were 33.743 ml/(100 g·min), 15.688, and 8.100 s, respectively, with significant differences (P &lt; 0.05). At 6 months after operation, the establishment of extracranial and extracranial collateral circulation was observed in all patients by re-examination of head DSA. At 6 months after operation, the good prognosis rate was 81.8%.

Conclusion

The Modified EDAS combined with superficial temporal fascia attachment-dural reversal surgery is safe and effective in the treatment of ischemic cerebrovascular disease, which can significantly increase the establishment of collateral circulation in the operation area and improve the prognosis of patients.