Extracranial carotid localized fibromuscular dysplasia: A case report and literature review

BACKGROUND: Fibromuscular dysplasia (FMD) is a noninflammatory and nonatherosclerotic arteriopathy that is characterized by irregular cellular proliferation and deformed construction of the arterial wall that causes segmentation, constriction, or aneurysm in the intermediate-sized arteries. The incidence of FMD is 0.42–3.4%, and the unilateral occurrence is even rarer. Herein, we report a rare case of a localized extracranial carotid unilateral FMD associated with recurrent transient ischemic attacks (TIAs) treated by extracranial-intracranial bypass for indirect revascularization. The specific localization of the disease rendered our case unique. METHODS: We conducted a review of the PubMed Medline database search using the following combined formula: ((FMD [Title/Abstract]) AND ((isolated [Title/Abstract]) OR (localized [Title/Abstract]))) AND Internal carotid artery (ICA) (Title/Abstract). Additional resources were included by screening the reference list of the selected papers. RESULTS: A total of six cases were found, and all accounted for localized FMD affecting the ICA. The age range was between 19 and 52, the male-to-female ratio was (2:4), and all of the cases consisted of unilateral carotid FMD, mainly on the left side with a left-to-right ratio of 5:1. The management and outcome of these cases varied according to the case and associated complications. CONCLUSION: Extracranial localized FMD of the ICA is a rare subtype of FMD that has little documentation in the literature. In our case, it was a localized extracranial carotid unilateral FMD associated with recurrent TIAs. The appropriate treatment was using the intracranial-extracranial bypass.