Ruptured traumatic posterior inferior cerebellar artery pseudoaneurysm: A case report and literature review

BACKGROUND: Traumatic intracranial aneurysm (TICA) accounts for approximately 1% of cerebral aneurysms. There are few reports of TICA limited to the posterior inferior cerebellar artery (PICA-TICA). CASE DESCRIPTION: A 69-year-old woman fell into a shallow river, bruising her head and chest, and was admitted to our emergency department with disorientation. Computed tomography (CT) showed subarachnoid hemorrhage (SAH), intraventricular hemorrhage (IVH), left temporal lobe contusion, and fractures of the right temporal bone. A cerebral CT angiogram revealed no vascular abnormalities or aneurysms. The patient was in a semi-comatose state 2 h later, and CT showed worsening SAH. A cerebral angiogram revealed an 11 mm aneurysm of the anterior medullary segment of the right PICA. We attempted intra-aneurysmal embolization intending to preserve the PICA, but the aneurysmal neck was thin, and the microcatheter could not be placed in a stable position. Therefore, n-butyl-2-cyanoacrylate (NBCA) was injected to embolize the aneurysm. When the microcatheter was removed, NBCA was scattered distally in the PICA, and the distal PICA was occluded. The aneurysm could be embolized, but there was an increase in hemorrhagic contusion in the left temporal lobe. Decompression craniectomy was performed, but she died due to hemorrhagic contusion and uncal herniation 6 days after surgery. CONCLUSION: PICA-TICA is often accompanied by IVH and SAH, and there are some reports of cases with a vascular anomaly of the posterior circulation. Since TICA is at risk of rapid growth and rupture, an early and appropriate diagnosis is important.