Postoperative symptomatic cerebral infarction in pediatric moyamoya disease: risk factors and clinical outcome

Abstract Background Indirect bypass surgery is used to improve the hemodynamic status of the pediatric moyamoya disease (MMD). Symptomatic cerebral infarction during the early postoperative period may be the most frustrating complication. Objective The purpose of this study is to investigate the factors associated with early post-operative symptomatic cerebral infarction. Methods Between January 2000 and February 2014, we performed 1241 indirect bypass surgeries for 659 pediatric MMD patients. Symptomatic infarction during the early postoperative period was diagnosed in 63 operations of 61 patients. Results The overall incidence of symptomatic cerebral infarction after indirect bypass surgery was 5.1 %. The median age of postoperative infarcted patients was 6 years (mean 6.4 years, range of 1 to 15 years). Performing of two craniotomies in single operation resulted in a higher rate of cerebral infarction. Moreover, young patients (under six years old) showed a relatively higher incidence than older patients. In a matched analysis, immediate postoperative hemoglobin levels of more than 13 g/dL was associated with decreased infarction risk (odd ratio=0.144, p=0.003). The mutation of the methylenetetrahydrofolate reductase (MTHFR) gene occurred in relatively high proportion of our infarction group. Conclusion Postoperative symptomatic infarctions can occur despite a unified surgical method and formulaic perioperative management protocol. Patient-centered factors, such as the young age, genetic background of MTHFR and particular medical conditions including hyperthyroidism, renovascular hypertension and hemolytic uremic syndrome, as well as management related factors including two craniotomies and low immediate postoperative hemoglobin level could be risk factors for early postoperative symptomatic cerebral infarction.