Prevalence and clinical implications of renal artery stenosis in pediatric moyamoya disease

• Eight of 101 (7.9%) pediatric MMD cases had renal artery stenosis.
• Renal artery stenosis in MMD can cause renovascular HT.
• The higher the cerebral angiographic staging of the MMD, the more renal artery stenosis was found in this study (p = 0.02).
• Renal artery involvement in MMD seems to be an important extracranial manifestation of MMD.

PurposeUntil recently, extracranial involvement of moyamoya disease (MMD) had not been fully elucidated. The purpose of this study was to determine the prevalence and clinical implications of renal artery stenosis in pediatric MMD patients.Materials & MethodsThis retrospective study included 101 pediatric (<18 years old) MMD patients who visited our hospital from July 2008 to May 2013. All patients had legible abdominal or renal angiography. Baseline characteristics, including hypertension (HT) and angiographic findings, were retrospectively evaluated.ResultThe median age was 8 (range 2–16) years. Six patients (5.9%) had HT. Renal artery stenosis was identified in 8 patients (7.9%). Five of 8 renal artery stenosis patients had HT. Statistical analysis showed that advanced stages of MMD and HT were associated with renal artery stenosis (p < 0.05).ConclusionRenal artery stenosis was not uncommon in pediatric MMD. Renal artery evaluation could help determine the cause of HT in advanced pediatric MMD cases. Further prospective and large-scale studies may be helpful in elucidating the extracranial manifestation of MMD.