Extensive Cerebrovascular and Visceral Artery Dissection and Pseudoaneurysm with Underlying Segmental Arterial Mediolysis.

Segmental arterial mediolysis (SAM) is a nonatherosclerotic, nonhereditary vasculopathy that most commonly involves abdominal aortic branches and predominantly affects middle-age and elderly populations. Lysis of the outer arterial media results in separation of the media from the adventitia leading to dissecting aneurysms and/or pseudoaneurysms. We report a unique case of a 47-year-old man who presented with bilateral internal carotid artery dissection followed by dissections and aneurysms involving multiple visceral arteries. This case highlights the dramatic manifestation of SAM and discusses the complexity of decision-making related to this disease including differential diagnoses and management.