Presentation
Severe headache. CT - rule out SAH.
Patient Data
There is small volume crescentic acute hemorrhage in the posterolateral aspect of the left cerebellar hemisphere with a minor hypoattenuating halo. Other acute blood extends to the undersurface of the tentorium. There is minimal localized mass-effect. There is no hyperdensity in the adjacent transverse and the sigmoid sinuses.
At the medial and the medial superior aspect of the left cerebellar hematoma, there is a compact niche of vessels measuring 13 mm transverse x 13 mm craniocaudal x 9 mm AP in keeping with a pial arteriovenous malformation. The main arterial feeders are via distal branches of the left superior cerebellar artery with contribution from distal branches of the left PICA. The main venous outflow is through cortical veins draining into the medial aspect of the left transverse sinus and the torcula herophili.
There is no aneurysm or severe steno-occlusive lesion in the major intracranial arteries. There is adequate contrast opacification of the major dural venous sinuses and the deep cerebral venous system.
Cerebral Angiogram & AVM embolization:
The AVM characterized previously, receives supply predominantly from PICA AICA SCA, with a compact nidus, and rapid arteriovenous shunting with drainage to the superior surface veins both medial and lateral. A 6Fr guiding catheter was placed in the LVA, an Apollo microcatheter navigated over a hybrid microwire into the medial PICA feeder at the nidus.
Onyx 18 injection with arterial, nidus, fistula obliteration complete.
Final angiographic runs demonstrate complete obliteration of the nidus, with no arteriovenous shunting, but some stasis in adjacent vessels.
Case Discussion
Spontaneous cerebellar hemorrhage in a young patient should prompt imaging to assess for underlying AVM or DAVF. CTA points to the abnormality, catheter angiography characterizes the nature of the arteriovenous shunting, differentiates DAVF from AVM, rules out associated flow aneurysms, and indicates whether endovascular intervention is possible.
In this case, the position of the nidus and relation to veins contribute to moderate surgical difficulty, and the access arteries favored microcatheter navigation with good arterial, nidal and local vein obliteration. Close follow up will be required to exclude recurrence.