The collateral circulation in pediatric moyamoya disease

Area of Science:

• Neurology
• Vascular Biology
• Pediatric Neurosurgery

Background:

• Moyamoya disease involves progressive stenosis of intracranial arteries, leading to the formation of abnormal collateral networks.
• Previous descriptions of collateral circulation in moyamoya have lacked systematic classification, mixing topographical and source-based analyses.

Purpose of the Study:

• To investigate the detailed anatomy of collateral circulation in pediatric moyamoya disease.
• To systematically classify the vascular anastomotic networks present in children diagnosed with moyamoya disease.

Main Methods:

• Retrospective analysis of angiographic studies from 25 children with newly diagnosed moyamoya.
• Categorization of patients into moyamoya disease (14) and moyamoya syndrome (11).
• Detailed examination of arterial supply, origin, course, location, and connections of moyamoya anastomotic networks.

Main Results:

• Four distinct types of anastomotic networks were identified: two superficial-meningeal (leptomeningeal and durocortical) and two deep-parenchymal (subependymal and inner striatal/thalamic).
• The leptomeningeal network includes previously described convexial and newly reported basal temporo-orbitofrontal patterns.
• The durocortical network can be basal or calvarian; deep networks involve novel subependymal, inner striatal, and inner thalamic connections.

Conclusions:

• The complex "moyamoya abnormal network" in pediatric moyamoya disease is composed of four distinct, classifiable anastomotic networks.
• A refined understanding of moyamoya collateralization angioarchitecture offers potential for a clinically relevant new staging system.