Type:
Educational Exhibit
Keywords:
Education and training, Arteriovenous malformations, Diagnostic procedure, Ultrasound, MR, CT, Vascular, Paediatric, Neuroradiology brain
Authors:
�. Calleja Bonilla1, A. B. Marin Quiles1, J. ROLDAN1, R. Bermejo Garcés2, E. R. Amador González1, A. Arias Medina3, M. A. Orozco Botero1; 1PALMA DE MALLORCA/ES, 2Tudela/ES, 3Sevilla/ES
DOI:
10.26044/ecr2019/C-3131
Background
Pediatric BVM are uncommon and have different features compared to adults,
and this is relevant for their classification and treatment.
Traditionally BVM are classified in shunting (Arterio Venous Shunt-AVS) or non-shunting lesions Fig. 1,
and AVS were divided according to arterial supply,
pial or dural.
This classification is inaccurate in children,
because:
- Cerebral eloquence is difficult to evaluate.
- Most lesions are fistulas or multifocal.
- The drainage pattern usually involves the entire venous system.
- The potential for recovery is different and the developing immature brain entails a group of nonhemorrhagic symptoms and therapeutic challenges absolutely different than adults.
Vasculogenesis is the process in which blood vessels are formed de novo.
Most pediatric BVM may develop in weak vessels (inherited or acquired),
so the vessel is more predisposed to develop a vascular lesion once a second “hit” happens.
When a trigger event creates a defect in the migrating cell,
the defect will be transmitted to daughter cells if this cell does not die.
Thus,
the effect,
size,
area,
and severity of the defect are related to the timing of when the triggering event occurred in relation to the migration; hence,
the earlier the hit,
the larger the effect on the vessels,
with a more widespread and severe vascular lesion.
Actually,
authors purpose new selection criteria according to lesion’s distribution in focal,
segmental or metameric,
based on a triggering event timing in endothelial cells precursors differentiation (Cruz et al 2015) Fig. 2.
BVM manifestations Fig. 3 rely on the lesion (type and placement),
the flow through the shunt,
the angioarchitectural (weak points),
venous drainage pattern and the magnitude of the venous outflow restriction.
- Most children will present an intracranial hemorrhage.
- Epilepsy as an initial clinical presentation occurs in fewer than 15% of pediatric patients,
though 70% of patients may develop epilepsy during the evolution of the disease.
In the neonatal group,
seizures will be secondary to brain damage rather than the AVS itself.
- Mass effect is rare,
but larger nidus or venous ectasias may lead to seizure,
focal neurologic deficits or hydrocephalus.