Low frequency of cervicocranial artery involvement in Japanese with renal artery fibromuscular dysplasia compared with that of Caucasians

Background: Fibromuscular dysplasia (FMD), which usually affects the renal artery, also affects the carotid, vertebral, and intracranial arteries. Previous studies have shown a high prevalence of concomitant renal artery and cervicocranial lesions in FMD patients. However, the analyzed subjects were mostly Caucasians in Western countries. Method: We performed a retrospective analysis to examine the prevalence of cervicocranial vascular lesions in Japanese FMD patients with renal artery involvement at a single institution. The presence of cervicocranial lesions was evaluated by Doppler echography and magnetic resonance angiography. We compared this prevalence with that reported in the literature. Result: Thirty-one Japanese FMD patients with renal artery lesions were studied. The mean age was 30 ± 12 years, 71% were women, and 16% were smokers; all patients were Asians and had hypertension. Multifocal, tubular, and unifocal types of renal lesions were found in 52, 35, and 13% of patients, respectively. Bilateral renal lesions were found in 13% of patients. None of the patients had a cervical vascular lesion associated with FMD. Only two patients (8%) had a lesion in the intracranial artery, of which one was a known case of moyamoya disease. Conclusion: These findings suggest that cervical artery involvement and intracranial artery involvement are not common in renal FMD patients in Japan, which is in contrast to the data reported for Caucasian patients in Western countries. Ethnic differences could influence the occurrence of cervicocranial lesions. A study with a larger sample size should be performed to validate these findings.