External Carotid Artery Pseudoaneurysm: A Rare Cause of Ischemic Stroke via Internal Carotid Artery Compression-A Case Report.

Pseudoaneurysms (PSAs) typically result from trauma, but their complications beyond rupture and bleeding remain understudied. We present a case of a 75-year-old male with atrial fibrillation who sustained a gunshot wound to the face, resulting in a left internal maxillary artery PSA. The patient was initially managed conservatively but developed right-sided hemiplegia and aphasia 14 days postinjury. CT angiography revealed near-complete occlusion of the left cervical internal carotid artery (ICA) due to extrinsic compression from the expanding PSA, originating from a branch of the external carotid artery (ECA). Emergent digital subtraction angiography confirmed ICA occlusion, and successful embolization of the PSA resulted in recanalization of the ICA and immediate neurological improvement. This case highlights a rare but significant complication of ECA-PSAs: ICA compression leading to ischemic stroke. This report underscores the importance of considering PSA-induced ICA compression as a potential cause of ischemic stroke in trauma patients, especially when neurological deficits develop. Prompt diagnosis and intervention are crucial for optimal patient outcomes.