Low Incidence of Neurological Adverse Events Among Pediatric Patients With Moyamoya Undergoing General Anesthesia for NonRevascularization Procedures

General anesthesia poses a significant risk for patients with MMA, yet its risk in the setting of nonrevascularization procedures remains unclear. Data regarding the risk of general anesthesia for nonrevascularization procedures are scarce. We therefore aimed to assess the incidence of neurological adverse events (NAEs) among pediatric patients with MMA undergoing general anesthesia for nonrevascularization procedures. We conducted a retrospective cohort study at a tertiary referral pediatric center of patients with MMA aged ≤18 years, who underwent general anesthesia for nonrevascularization procedures between January 2014 and July 2023. Postanesthesia NAEs were defined as occurrence of transient ischemic attacks, seizures, altered mental status, severe headache, or evidence of arterial ischemic stroke (AIS) in the 30 days postprocedure. Among 149 procedures on 38 patients (median age [interquartile range]: 8.3 [5.0, 12.7] years; 57% female), 124 (83.2%) procedures were imaging studies and angiographies and 25 (16.8%) were surgical procedures. Preprocedural hyperhydration treatment was administered before most (111, 74.5%) procedures per our institutional protocol. The incidence of postanesthesia NAEs was 0.67% (one of 149), as a result of acute AIS following a ventriculoperitoneal shunt revision surgery, in a patient with postradiation MMA, panhypopituitarism, and uncontrolled diabetes insipidus, despite preprocedural hyperhydration treatment. There were no NAEs after imaging studies performed under general anesthesia. Our results suggest that general anesthesia for nonrevascularization procedures in pediatric patients with MMA prepared with hyperhydration is safe. As neuroradiological follow-up is central in children with MMA, this information can be valuable for reassuring patients and their families.