Precision Bypass in Patients With Moyamoya Disease

Extracranial-intracranial arterial bypass, including anastomosis of the superficial temporal artery to the middle cerebral artery and indirect bypass, can help prevent further ischaemic attacks in patients with Moyamoya disease (MMD). However, there is no established standard for the selection of the recipient vessels. In most situations, surgeons choose the recipient vessels with their own experiences. Intraoperative Indocyanine green (ICG) angiography using Flow800 software and multimodal neuronavigation can be used to assess the real-time cerebral blood flow velocity and perfusion of local brain tissue for better selection of the recipient vessels. Thus the aim of this study is to to determine whether direct bypass surgery combined with multimodal neuronavigation is superior to traditional direct bypass procedure alone in adult ischemic MMD patients.

There are no effective medical therapies for moyamoya disease. Through the provision of collateral pathways, surgical revascularisation is the most successful therapy to improve cerebral haemodynamics, and to reduce the risk of subsequent stroke. Surgical procedures for moyamoya disease can be classified into three categories: direct bypass, indirect bypass, and combined bypass. Although surgeons have their own experience choosing the recipient vessels,no standard has been established based on a worldwide consensus.

Intraoperative ICG angiography using Flow800 software and multimodal neuronavigation (structure combined with perfusion MRI sequence) can be used to assess the real-time cerebral blood flow velocity and perfusion of local brain tissue, which is contribute to choose a recipient vessels with relative low cerebral blood flow velocity and perfusion.

Therefore,the PBM study in our institution is designed to compare the direct bypass surgery with multimodal neuronavigation with traditional direct bypass procedure alone in preventing any ischemic event afterwards after cerebral revascularization surgery in adult ischemic MMD patients.

Eligibility Criteria:
Inclusion Criteria:

* Independent in activity of daily living(The modified Rankin Scale 0-2)
* At least one month since the most recent ischemic stroke
* The neurological deficit must be stable for more than 6 weeks
* Digital substraction angiography demonstrating progressive stenosis or occlusion in the terminal portion of the internal carotid artery and/or the initial portion of the anterior or middle cerebral arteries
* Digital substraction angiography demonstrating formation of abnormal collateral networks (moyamoya vessels) at the base of the brain, mainly in the region of thalamus and basal ganglia
* Digital substraction angiography demonstrating the vasculopathy appeared unilaterally or bilaterally
* Competent to give informed consent
* Accessible and reliable for follow-up

Exclusion Criteria:

* Other diseases(such as internal carotid artery stenosis, internal carotid artery dissection, atrial fibrillation, or Intracranial atherosclerosis) probably causing ischemic strokes
* Not independent in activity of daily living(The modified Rankin Scale 3-5)
* Moyamoya syndrome concomitant with other hereditary or autoimmune diseases (Grave's Disease,Type I Diabetes Mellitus,Type I Neurofibromatosis et al)
* Patient whose initial onset was marked by ischemia but subsequently suffered from intracranial hemorrhage
* Emergent evacuation of intracerebral hematoma damaging superficial temporal artery or cortical artery
* Emergent decompressive craniotomy causing automatically developed indirect revascularization
* Good collateral networks formed by spontaneous anastomosis between extracranial and intracranial vessels before surgery
* Life expectancy\<1 years
* Pregnancy
* Unstable angina or myocardial infarction with recent 6 months
* Blood coagulation dysfunction
* Allergic to iodine contrast agent
* Abnormal liver function(alanine transaminase (ALT) and/or aspartate aminotransferase (AST)\>3 times of normal range)
* Serum creatinine \>3mg/dl
* Poorly controlled hypertension (systolic BP\>160 mmHg,diastolic BP\>100 mmHg)
* Poor glucose control (fasting blood glucose\>16.7mmol/l)
* Concurrent participation in any other interventional clinical trial
* patients refused to participate in the study