Paediatric cervicomedullary perimedullary arteriovenous fistula presenting with intraventricular and subarachnoid haemorrhage: curative bilateral parallel-coiling

This boy in mid childhood presented with a sudden, excruciating occipital headache following a week of progressive gait unsteadiness and neck-accentuated meningeal pain. CT demonstrated tetraventricular haemorrhage with early obstructive hydrocephalus and perimesencephalic subarachnoid blood. CT angiography/magnetic resonance angiography (MRA) and digital subtraction angiography revealed a cervicomedullary perimedullary arteriovenous fistula (PMAVF) supplied by the anterior and posterior spinal arteries with a single venous pouch aneurysm at C3-4. Emergency external ventricular drain (EVD) placement was performed. Definitive endovascular cure was achieved 72 hours later using simultaneous bilateral micro-catheterisation of the venous pouch and 'parallel' coiling under multimodality neuromonitoring, completely occluding the shunt while preserving spinal arterial flow. The patient recovered without any neurological deficit, the EVD was gradually weaned over the first 5 postoperative days and removed without clinical or radiological difficulty, and the 12-week MRI/MRA confirmed complete occlusion; at that time, he had returned fully to school and sports including football. This case highlights the importance of cervicomedullary vascular imaging in atraumatic paediatric Subarachnoid Hemorrhage (SAH)/intraventricular haemorrhage and illustrates that complex type III/C PMAVFs can be safely cured in a single session using a dual-pedicle coiling strategy in select cases.