Long-term follow-up of surgically treated juvenile patients with Moyamoya disease

Surgical revascularization is considered an effective treatment for juvenile patients with moyamoya disease (MMD). Yet the long-term outcome in surgically treated patients still needs to be clarified. More than 30 years have passed since the authors' department started intensively treating pediatric patients with MMD using indirect anastomosis techniques. In this study the authors surveyed the current status of these patients.

Activities of daily living (ADLs) were surveyed and present clinical status was assessed based on the modified Rankin scale (mRS). Cerebrovascular events subsequent to surgical treatment were also recorded.

Since 1979, 208 patients younger than 19 years of age with MMD were surgically treated and followed up for > 3 years. Data were available on 172 patients (83%), who had been followed up for a mean of 14.3 years (range 3-32 years). Activity of daily living outcomes were as follows: 138 patients (80.2%) had mRS scores of 0-2, 29 (16.9%) a score of 3, 1 (0.6%) a score of 4, 1 (0.6%) a score of 5, and 3 (1.7%) a score of 6. Cerebrovascular events occurred 8 or more years after surgery in 6 patients (3.4%), that is, 6 hemorrhages and 3 infarctions. The cumulative risk of late-onset stroke at 10, 20, and 30 years after surgical intervention was 0.8%, 6.3%, and 10.0%, respectively.

This long-term survey demonstrated that most surgically treated pediatric patients with MMD maintain good ADL outcomes. However, a significant number of new cerebrovascular events occurred more than 10 years after the initial surgery. Additional follow-up will help to identify which events may occur during the adult years of patients treated as children.