To explore the clinical characteristics and risk factors of unstable moyamoya disease.

The clinical data of 261 patients with moyamoya disease, who received combined cerebral reconstruction in the Moyamoya Disease Center of Henan Provincial People's Hospital from January 1, 2019 to December 31, 2019, were analyzed retrospectively. The clinical variables of stable group and unstable group were compared, and the clinical characteristics of unstable moyamoya disease were summarized. Univariate and multivariate logistic regression analysis was used to summarize the risk factors of unstable moyamoya disease.

The patients with unstable moyamoya disease showed higher frequency of preoperative TIA attacks (OR=3.439, P=0.023) and higher systolic blood pressure (OR=1.097, P＜0.001). The incidence of new-onset postoperative stroke events in the unstable group was 42.31% (11/26), which was significantly higher than that of stable group (3.40%, 8/235; χ²=39.133, P＜0.001).

Unstable moyamoya disease has asymmetrical changes of bilateral intracranial vessels on imaging, and such patients are more likely to present frequent preoperative TIA attacks and higher uncontrollable blood pressure. New-onset stroke events are more likely to occur after combined cerebral blood flow reconstruction. For this group of patients, we should strengthen the perioperative evaluation management, implement detailed surgical plans and postoperative management to prevent complications, which is fundamental to reduce the mortality and disability of surgical treatment of moyamoya disease.