Abstract
The posterior cerebral artery (PCA) is an important source of collateral blood supply to the anterior circulation in moyamoya disease. It has been reported that some patients with moyamoya disease require additional surgery after revascularization surgery of the anterior circulation due to delayed progression of PCA stenosis or occlusion.
This study included 68 pediatric patients with moyamoya disease who underwent revascularization surgery of the anterior circulation in our institute and followed up for a minimum of three years. At onset, the PCA was involved in 17 patients, and the PCA was intact in 51 patients. Of the 51 patients with an intact PCA, 10 (19.6%) presented with delayed progression of PCA stenosis or occlusion, and seven (13.7%) required additional revascularization surgery for the PCA territory. The average interval between initial surgery and additional surgery was 6.1 years. Five patients were symptomatic, and two patients were asymptomatic. All symptomatic patients exhibited transient ischemic attacks (visual disturbance in 5 patients and sensory disturbance in one patient). In asymptomatic patients, MRA showed progression of PCA stenosis, and single-photon emission computed tomography (SPECT) revealed markedly decreased uptake in the PCA territory.
Encephalogaleosynangiosis (EGS) was performed in all patients. All symptomatic patients showed clinical improvement. In both the asymptomatic patients, postoperative SPECT demonstrated an increase of uptake in the PCA territory.
EGS for the PCA territory is effective for improving clinical symptoms and radiological findings in pediatric patients with moyamoya disease who showed delayed progression of PCA stenosis. Even in asymptomatic patients, surgery should be considered, because it is difficult for young pediatric patients to describe transient visual impairment.
