Neurointervention.  2024 Jul;19(2):129-134. 10.5469/neuroint.2024.00136.

Endovascular Management of a Ruptured Aneurysm on a Posterior Inferior Cerebellar Artery with Extradural C2-Origin: Case Report and Literature Review

• Dahl RH
• Horn Jr GL
• Metwalli Z
• Gopinath SP
• Benndorf G

• KMID: 2556666
• DOI: http://doi.org/10.5469/neuroint.2024.00136

Abstract

Extracranial vascular pathology uncommonly causes intracranial subarachnoid hemorrhage (SAH). Among possible lesions are aneurysms at the craniocervical junction arising from a posterior inferior cerebellar artery (PICA) with an extradural origin. We describe a case of a 55-year-old female presenting with a sudden and severe headache. A computed tomography scan revealed a SAH within the fourth ventricle and cervical spinal canal, and a ruptured saccular aneurysm on a PICA with extradural C2-origin. Despite difficult access anatomy, endovascular treatment was feasible and resulted in subtotal initial occlusion and preservation of distal PICA flow. Upon 3-month follow-up, the aneurysm was completely occluded with a patent PICA. The patient’s clinical status remained stable at the 1.5-year follow-up. In conclusion, we present a rare case of an aneurysm originating from a PICA with extradural C2-origin that was treated endovascularly with preservation of the PICA.

Keyword

Aneurysm; Endovascular treatment; Extracranial; Vascular variant; Coil embolization

Figure

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  Fig. 1. (A) Axial computed tomography (CT) scans on admission show blood in the fourth ventricle (white arrow) and subarachnoid hemorrhage at the craniocervical junction (inset). (B) Coronal CT angiography shows a small saccular structure at the C1-level (white arrow) that appears to arise from a posterior inferior cerebellar artery (PICA) with an extradural origin. (C) Right vertebral artery injections show a PICA arising from the V3-segment with an intradural aneurysm (long arrow) carrying a small bleb (short arrow). Lateral non-subtracted image shows the location of the aneurysm in the spinal canal (white arrow; inset). (D) Follow-up 9 months after aneurysm rupture shows a subtle change in shape with the bleb less clearly visible (arrow). (E) Control run after aneurysm coiling (3 coils) with a small neck remnant (long arrow), intentionally left to preserve PICA flow. Position of distal access catheter that facilitated distal microcatheter navigation into the PICA and the aneurysm (short arrow). Small anastomotic branch arising from the usual PICA origin of the V4 segment (curved arrow). (F) Follow-up angiogram 3 months after treatment shows progression of aneurysm occlusion that is now complete (arrow), while flow in the distal PICA is preserved.

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  Fig. 2. Illustration of a posterior inferior cerebellar artery (PICA) with extradural C2-origin. A muscular branch may arise from the extradural segment of the artery. An intradural small anastomotic branch between the vertebral artery and PICA is sometimes found. Extracranial aneurysms may arise proximally at the level of dural penetration (1) or distally on the ascending vertical segment (2). Aneurysms may also develop on the intracranial PICA (3).

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