Pial arteriovenous fistula

Case contributions: Dr Radhiana Hassan

Clinical:

  • A 14 years old girl
  • Presented with sudden onset of headache and altered consciousness
  • No history of fever or trauma
  • Urgent non-contrast CT brain shows intraparenchymal and intraventricular hemorrhage
Contrast enhanced CT scan brain in axial plane

Contrast-enhanced CT scan after EVD insertion shows:

  • massive intraventricular hemorrhage with hydrocephalus (yellow arrows)
  • dilated vessels at right parietal region (white arrows)
  • No aneurysm seen
CTA with reconstructed images
  • A dilated vessels seen with single draining vein
  • No aneurysm
Digital subtracted angiogram

Digital subtracted angiogram shows

  • A dilated artery from distal branches of callosomarginal artery on the right side
  • No early draining vein seen
  • No nidus, no saccular aneurysmal dilatation
  • A few turn of the artery with single draining vein seen

Diagnosis: Pial arteriovenous fistula

Discussion:

  • Pial AVF is a rare vascular malformations accounting for 1.6% of all intracranial vascular malformations
  • It consist of a single dilated pial artery connected to an enlarged cortical draining veins
  • It differs from AVM because it do not have a nidus
  • It differs from dural AVF because it arise from pial artery rathet than a dural artery
  • Treatment options: endovascular embolization or microsurgical resection.
  • Stereotactic radiogsurgery is considered in cases difficult to reach or lesion is too small. However success is less than in AVM
Author: radhianahassan