Challenging direct bypass surgery for very young children with moyamoya disease: technical notes.

Cerebral revascularization for moyamoya disease (MMD) is an effective treatment for improving cerebral ischaemia and preventing rebleeding. Although direct bypass surgery is commonly performed on older children and adults, it is challenging in very young children due to the high difficulty level of the procedure. The subjects were MMD patients under 3 years of age on whom surgery was performed by a single surgeon (Y.A.). Preoperative clinical findings, information related to direct bypass surgery, bypass patency, and the incidence of postoperative stroke were investigated. Combined revascularization, including direct bypass surgery, was performed on 3 MMD patients (3 sides) under 3 years of age. The average diameter of the grafts used in direct bypass was 0.8 mm. The average recipient diameter was 0.8 ± 0.17 (range 0.6-1) mm. In all cases, the anastomotic procedure was completed using 11-0 monofilament nylon thread, and patency was confirmed. Direct bypass for MMD patients under 3 years old is technically challenging. However, despite the anatomical differences between very young children and elderly individuals, direct bypass surgery could certainly be completed. In addition, a rapid recovery from cerebral blood flow insufficiency could yield a promising neurological outcome.