Surgical Treatment of Moyamoya Disease by Indirect Revascularization Procedure

ABSTRACT

Indirect revascularization procedures were performed on 50 hemispheres of 33 patients with moyamoya disease from January 1986 to August 1994. There were 23 females and 10 males, ranging from 1.4 to 58 years in age(mean 14.1 years). The interval from the onset of symptoms to surgery was 3 months and less in fourteen, and more than 3 months in nineteen patients(mean 1.2 years). The types of progression were variable TIA-infarction type in 15 patients, infarction type in ten, ruptured type in five. TIA/frequent TIA type in two and infarction-TIA type in one patient. Bilateral Encephalo-duro-arterio-synangiosis(EDAS) was performed in 16 patients, unilateral EDAS in twelve, unilateral encephalo-myo-arterio-synangiosis(EMAS) in two, unilateral encephaloduroarteriomyosynangiosis(EDAMS) in two, and bilateral EDAMS in one patient. The patients were followed postoperatively for periods between 7 to 79 months(mean 31 months). The Activity of daily living(ADL) on admission was not good in patients below the age of 6 years at onset and showing repeated ischemic attacks before operation. The result of operation with regard to prevention of ischemic or hemorrhagic attack was excellent on 38 hemispheres(76%), good on five(10%), fair on two and poor on five hemispheres. The operations were done on the 39 symptomatic hemispheres and 11 asymptomatic hemispheres, which resulted in excellent or good results in thirty three(84.6%) and ten hemisphers(90.9%), respectively. The patients in which the interval between onset of symptoms and operation was more than 3 months showed more severe neurological deficit due to poorer neurological status at the time of operation compared with the group who underwent operation before 3 months from the onset. Three patients suffered perioperative cerebral infarction caused by hyperventilation during anesthesia or severe crying. It is concluded that the indirect revascularization procedures are effective for the prevention of ischemic or hemorrhagic attack in patients with moyamoya disease. If surgery is performed before permanent deficits have developed, the patient may be spared of neurological disability.