Changes in Surgical Treatment for Pediatric Moyamoya Disease

Abstract

Pediatric patients with moyamoya disease frequently exhibit extensive cerebral infarction at the time of initial presentation and even in the early postoperative period. Cerebral infarctions are more frequent in younger patients. Surgical revascularization is the treatment of choice for patients with moyamoya disease. We modified surgical strategies for patients with moyamoya disease to reduce the incidence of postoperative cerebral infarction. Between January 2004 and December 2015, 46 patients (74 hemispheres) with moyamoya disease, aged ＜18 years, were surgically treated at our hospital. Surgical strategy entailed indirect bypass by encephalo-galeo-myo-duro-synangiosis (EGMDS) (3 hemispheres) for the first era, EGMDS and superficial temporal artery-middle cerebral artery (STA-MCA) single anastomosis (67 hemispheres) for the second era, and EGMDS and double STA-MCA anastomosis (4 hemispheres) for the third era. A review of clinical findings and radiological data showed that surgical treatment is effective for patients with moyamoya disease. Direct bypass can reduce the incidence of postoperative cerebral infarction, especially in younger patients. Postoperative cerebral infarctions were observed in 8 patients, all of whom were aged ＜6 years. Of these, 5 infarctions occurred in the ipsilateral hemisphere (6.8%) and 3 in the contralateral hemisphere (4.0%). Postoperative temporary neurological deficit due to hyperperfusion that had completely resolved by the time of discharge was seen in 9 hemispheres. Considering these results, direct bypass can induce immediate improvements in cerebral circulation that are suitable for patients with rapidly progressive moyamoya disease. However, direct bypass is not completely safe for pediatric patients with moyamoya disease because of the resulting changes in postoperative cerebral hemodynamics. To prevent such complications, we recently performed STA-MCA double bypass as an initial treatment for patients with a high risk of cerebral infarction that can increase cerebral perfusion in areas supplied by both the upper and lower trunks of the middle cerebral artery in a balanced manner. The outcome of this strategy was favorable.