Flow-Mediated Dilatation of the Brachial Artery for Assessing Endothelial Dysfunction in Children with Moyamoya Disease

Background:Moyamoya disease is a progressive, steno-occlusive arteriopathy involving the internal carotid artery and its branches and causing recurrent stroke episodes in children. Patients with moyamoya disease may be more susceptible to influences that cause endothelial dysfunction. We evaluated whether flow-mediated dilatation (FMD) of the brachial artery is useful for assessing endothelial dysfunction in children with moyamoya disease.Methods:This prospective observational study included 30 children with moyamoya disease and 30 controls. After anesthesia induction, a blood pressure cuff was applied to the forearm and inflated to a pressure that was 50 mm Hg above the baseline systolic blood pressure for 5 min. From 30 s before to 2 min after deflation, the brachial artery diameter was recorded on ultrasound. The increase in internal diameter was expressed as the percentage of the baseline diameter.Results:Fifty-nine patients were analyzed. Baseline brachial artery diameters in the moyamoya and control groups were 3.00 and 3.37 mm, respectively (p= 0.004; difference, 0.38; 95% CI 0.12-0.63), while those after deflation were 3.06 and 3.48 mm, respectively (p= 0.003; difference, 0.42; 95% CI 0.15-0.68). The percent change of the baseline diameter value was 4.0% in the disease group and 8.3% in the control group (p= 0.10). There was a group and time interaction for brachial artery diameter (p= 0.01; main effect of group,p= 0.009; main effect of time,p= 0.007).Conclusion:FMD of the brachial artery may not be enough for determining endothelial dysfunction under general anesthesia in children with moyamoya disease.