Pediatric Growth Patterns of the Circle of Willis: Systematic Review and Implications for Clinical Neurovascular...

The Circle of Willis (CoW) ensures cerebral perfusion and collateral support, yet pediatric CoW growth is poorly described compared to adults. Clarifying its developmental trajectory is essential to optimize planning and execution of endovascular/surgical procedures. This systematic review assesses pediatric CoW development, identifies gaps in current knowledge, and explores the implications for future diagnostics and interventions.

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, databases including PubMed, ClinicalTrials.gov , Cochrane Library, ScienceDirect, Web of Science, and Medline were searched using terms such as Circle of Willis, intracranial arteries, cerebrovascular system, children, growth, development, and pediatric cerebrovascular development . Articles from January 1987 to September 2024 were screened.

Of 513 articles identified, 3 met inclusion criteria, totaling 608 pediatric subjects. All studies described a biphasic growth pattern, rapid arterial expansion during infancy followed by slower growth, and demonstrated strong correlations between vessel dimensions and head circumference. Children exhibited greater CoW symmetry and fewer anatomic anomalies than adults, challenging the assumption that vascular configurations stabilize or improve only with age. This suggests that factors driving asymmetry in adulthood, environmental, hemodynamic, or structural, warrant further study.

Pediatric CoW development follows a tightly regulated, region-specific timetable linked to skull and brain maturation. However, small sample sizes, uneven age distributions, and limited longitudinal data constrain current insights. Future research should use 4D flow MRI, balanced longitudinal cohorts, and integrated geometric-hemodynamic assessments, and explore correlations with other cerebral structures to improve early detection of anomalies and guide targeted endovascular and surgical interventions in pediatric cerebrovascular care.