Reduction of systemic hypertension following cerebral revascularization surgery for children with moyamoya

OBJECTIVE: The aim of this study was to evaluate whether indirect revascularization is associated with a reduction in systemic blood pressure (BP) over time in pediatric patients with moyamoya. METHODS: This is a retrospective cohort study of pediatric patients with moyamoya who were treated at a single institution between June 2019 and January 2025. BP measurements were collected preoperatively (preadmission clinic evaluation) and postoperatively (outpatient follow-up evaluation at ≥ 3 months). BP was categorized as hypertensive or normotensive based on percentile thresholds adjusted for age, sex, and height, with measurements at the 95th and 99th percentiles indicating hypertension. The chi-square test was used to assess changes in hypertensive classification, and the paired t-test was used to compare mean absolute BP values at the two time points. RESULTS: Overall, 63 children (39 female, mean age 11 years) with moyamoya who underwent indirect revascularization surgery were included in this analysis. The mean follow-up duration was 20.8 months. Preoperatively, 21 patients (33.9%) were classified as hypertensive for systolic BP and 9 (14.5%) for diastolic BP. These measurements were acquired preoperatively at a mean of 3.5 months (range 1 day to 11 months). Postoperatively, the proportion of hypertensive patients decreased to 10 (16.1%) and 3 (4.8%) for systolic BP and diastolic BP (p = 0.02 and 0.06, respectively). There was no significant change between the preoperative and postoperative mean arterial pressure measurements (77.3 mm Hg vs 76.2 mm Hg, respectively; p = 0.52). CONCLUSIONS: Indirect revascularization surgery in pediatric patients with moyamoya was associated with a reduction in hypertension over time. This might reflect the delayed physiological effect of indirect revascularization, in which neovascularization and improved cerebral perfusion typically develop 3-6 months after surgery. Understanding BP changes following surgery might help avoid unnecessary use of antihypertensive drugs, which carry risk of precipitating hypotension and thus stroke.