Posterior Communicating Artery Aneurysm: Posttraumatic Pseudoaneurysm in a Child, Coil Occlusion and Flow Diverter Implantation, Hemorrhage Protection, Arterial Reconstruction with Relief of Mass Effect and Good Outcome

Abstract

A large pseudoaneurysm was diagnosed at the proximal right posterior communicating artery (PcomA)-internal carotid artery (ICA) axillary junction in a 7-year-old boy eight days after he had suffered multiple traumatic injuries, including severe head injury, in a motor vehicle accident. His admission Glasgow Coma Scale (GCS) score was 7. Head CT showed diffuse subarachnoid hemorrhage (SAH) and a linear sphenoidal fracture. Following ventriculostomy, the patient’s intracranial pressure (ICP) was controlled for the first 12 h, allowing him to undergo urgent spinal and orthopedic interventions, but his ICP was consistently elevated after completion of these surgeries. Decompressive craniectomy was therefore performed 26 h after admission, enabling good ICP control. Routine neurological evaluation showed some improvement, with GCS alternating between 8 and 12. However, after eight days, the patient unexpectedly developed a full-blown right palsy of cranial nerve (CN) III. Urgent CT and CT angiography (CTA) showed the development of a carotid pseudoaneurysm. Cerebral angiography confirmed the presence of a right PcomA-ICA pseudoaneurysm. Coiling was performed to reduce the risk of impending hemorrhage and the CN III palsy recovered completely after 12 h. In a second procedure, performed two weeks later, a flow-diverter stent was implanted. The patient had a rapid clinical recovery after intense rehabilitation. Angiography performed six months after stent implant confirmed complete exclusion of the aneurysm and reconstruction of the ICA. This case illustrates the staged management of an unusual but life-threatening condition, supporting the use of flow diverter stents for occlusion of subacute aneurysms. It contributes to the limited available literature on the endovascular management of pseudoaneurysms in pediatric patients.