Researchers identify risk factors for postoperative cerebral ischemia in patients with moyamoya disease

The buildup of fats, cholesterol, calcium, and immune cells within the blood vessel can lead to the narrowing or even complete blockage of the blood vessel. This condition, called stenosis, can lead to various disorders. Moyamoya disease (MMD) results from stenosis of the blood vessel in the neck that supplies blood to the brain (distal internal carotid artery (ICA)), as well as its branches. This leads to the suboptimal blood supply to the brain, a condition termed cerebral ischemia. Currently, the main treatment strategy for MMD involves the surgical augmentation of blood supply to the brain (neovascularization). However, neovascularization is associated with cerebral ischemia risks. The prediction of cerebral ischemic events after surgery has been challenging, mainly because the related risk factors have not been identified.

To address this knowledge gap, a research team led by Dr. Yuanli Zhao and Prof. Rong Wang examined the medical imaging features of 119 patients with ischemic MMD who underwent neovascularization surgery at the Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University. The study was published in the Chinese Neurosurgical Journal on 14 April 2026. Commenting on the rationale of the study, Dr. Zhao remarked, "The incidence of cerebral ischemia after revascularization surgery in MMD is about 5%. The identification of risk factors for postoperative cerebral ischemia can aid in developing predictive tools and consequently improving patient outcomes."

All patients in this study underwent digital subtraction angiography (DSA), magnetic resonance imaging (MRI), and computerized tomography (CT) perfusion before surgery. In DSA, the blood vessel of the brain is visualized using dye injected via a catheter. After the neovascularization surgery, the patients underwent CT at 4–6 h post-surgery and head MRI at days 5–7 post-surgery. Cerebral artery blockage was quantified using the Suzuki staging system. Oxygen deprivation-induced tissue death (infarction) was identified based on a low-density signal in the CT scan or a prominent signal in the MRI. The researchers examined postoperative infarctions around major arteries. New infarctions developed in 11 hemispheres in 8 patients (5.5% of the patients), while infarctions on both sides of the brain were observed in 3 patients. Severe blockage of the major cerebral arteries (anterior, middle, and posterior cerebral arteries) was associated with postoperative infarction.

DSA of cerebral arteries was performed for 3 patients who presented with cerebral ischemia after the surgery. In these patients, brain imaging before the surgery was characterized by severe occlusion of the major arteries. This confirmed the preoperative occlusion of the major arteries as a risk factor for postoperative cerebral infarction. According to Prof. Wang, "The findings of this study can aid clinicians to predict cerebral ischemia events after revascularization surgery and implement relevant mitigation strategies, improving the treatment outcomes."

Although this study identified a risk factor for postoperative cerebral infarction, the roles of other confounding factors, such as age and surgery side, cannot be ruled out, warranting further studies with a larger sample size. However, this study has laid the foundation for evaluating other risk factors and developing therapeutic or management strategies to minimize the incidence of postoperative cerebral infarction in patients with MMD.