Incidence of cerebral hyperperfusion syndrome following revascularization surgery in moyamoya patients: a systematic review and meta-analysis.

Moyamoya disease (MMD) is a chronic cerebrovascular disorder marked by the narrowing of the internal carotid artery and the formation of atypical collateral blood vessels. To reduce the risk of ischemic or hemorrhagic events, surgical revascularization is considered the standard treatment. Also, a major postoperative concern is cerebral hyperperfusion syndrome (CHS), which results serious complications such as seizures and intracranial hemorrhage. This systematic review and meta-analysis aimed to evaluate the incidence of CHS in patients with MMD undergoing cerebral revascularization surgery. A comprehensive database search was conducted from the inception until October 6th, 2024 in order to identify the eligible studies that reported sufficient data regarding CHS and its associated complications among MMD patients undergoing cerebral revascularization surgery. A total of 177 articles were screened, and 23 studies consisting of 2083 patients were included in this study. The pooled incidence of CHS was 23% (95% CI: 17–30%), with higher rates in direct revascularization (27%) compared to combined methods (21%). The incidence of postoperative seizures was 8% (95% CI: 5–11%), and hemorrhage was 15% (95% CI: 7–24%). No significant publication bias was detected. This study highlights the incidence of CHS following revascularization procedures. The associated complications, such as seizures and hemorrhage, underscore the need for intensive monitoring. These findings emphasize the importance of personalized surgical planning and optimized diagnostic approaches to improve patient outcomes in CHS management.