WHEN TO SEARCH FOR CEREBROVASCULAR LESIONS IN PATIENTS WITH RENAL ARTERY FIBROMUSCULAR DYSPLASIA: HINTS FROM THE ARCADIA-POL STUDY

Objective: Previous reports have shown a high prevalence of concomitant renal and cerebrovascular Fibromuscular Dysplasia (FMD). However, systematic whole body CT scan was performed in only few studies. Furthermore, distinctive features of patients with or without cerebrovascular FMD have not been reported in detail. The aim of this study was to assess the prevalence of cerebrovascular involvement in patients with renal FMD included in the ARCADIA-POL study and to look for differences between patients with and without cerebrovascular involvement. Design and method: We reviewed all patients included in ARCADIA-POL. Only those with a confirmed diagnosis of renal FMD were eligible for the analysis. All patients underwent a detailed evaluation including CTA from brain to pelvis. Cerebrovascular involvement was defined as the presence of any of the following lesions: stenosis, aneurysm, dissection and/or S-shaped cervical artery. Results: Of 203 patients with renal FMD (84% women, age at diagnosis: 42.1 ± 15.7 yo), 29% (n = 58) had cerebrovascular FMD, among whom 45% harboured intracranial aneurysms. When compared with patients without cerebrovascular FMD, patients with cerebrovascular FMD were overwhelmingly of the multifocal renal subtype (93% vs. 75%, p = 0.004), older at FMD diagnosis (46.3 vs. 40.4 yo. p = 0.01) and more frequently smokers (35% vs. 21%; p = 0.046). They also presented more often with bilateral renal FMD (35% vs. 17%, p = 0.002) and FMD in a third vascular bed (36% vs. 4%, p < 0.001). Conclusions: In the ARCADIA-POL registry, the prevalence of cerebrovascular FMD in patients with renal FMD was lower than in previous studies. Notably however, almost half of them harboured cerebral aneurysms. Patients with cerebrovascular FMD were overwhelmingly of the multifocal subtype, and had more often bilateral lesions and widespread disease. Screening for cerebrovascular FMD should be prioritized in patients with bilateral renal FMD of the multifocal subtype. The interest of screening for cerebrovascular FMD in patients with focal renal FMD is questionable.