Pediatric and adult patients with moyamoya disease experience similar clinical benefits from indirect revascularization surgeries, but there are still debates about age-related angiographic differences of the collaterals established after surgery. The goal of this study was to assess age-related differences on ultrasonography before and after indirect revascularization surgeries in moyamoya patients, focusing on some ultrasonographic parameters known to be correlated with the collaterals supplied by the external carotid artery (ECA).
The authors prospectively included moyamoya patients (50 and 26 hemispheres in pediatric and adult patients, respectively) who would undergo indirect revascularization surgery. Before surgery and at 1, 3, and 6 months after surgery, the patients underwent ultrasonographic examinations. The ultrasonographic parameters included peak-systolic velocity (PSV), end-diastolic velocity (EDV), resistance index (RI), and flow volume (FV) measured in the ECA, superficial temporal artery (STA), and internal carotid artery on the operated side. The mean values, absolute changes, and percentage changes of these parameters were compared between the pediatric and adult patients. Logistic regression analysis was used to clarify the determinants affecting postoperative EDV changes in the STA.
Before surgery, the adult patients had mean higher EDV and lower RI in the STA and ECA than the pediatric group (all p < 0.05). After surgery, the pediatric patients had greater changes (absolute and percentage changes) in the PSV, EDV, RI, and FV in the STA and ECA (all p < 0.05). The factors affecting postoperative EDV changes in the STA at 6 months were age (p = 0.006) and size of the revascularization area (i.e., revascularization in more than the temporal region vs within the temporal region; p = 0.009). Pediatric patients who received revascularization procedures in more than the temporal region had higher velocities (PSV and EDV) in the STA than those who received revascularization within the temporal region (p < 0.05 at 1–6 months), but such differences were not observed in the adult group.
The greater changes of these parameters in the STA and ECA in pediatric patients than in adults after indirect revascularization surgeries indicated that pediatric patients might have a greater increase of collaterals postoperatively than adults. Pediatric patients who undergo revascularization in more than the temporal region might have more collaterals than those who undergo revascularization within the temporal region.