An indirect revascularization method in the surgical treatment of moyamoya disease - Various kinds of indirect procedures and a multiple combined indirect procedure

The indirect non-anastomotic bypass procedures for moyamoya disease are herein reviewed, and our multiple combined indirect procedure, i.e. a fronto- parieto-temporal combined indirect bypass procedure, is also introduced. Direct procedures such as superficial temporal artery-middle cerebral artery anastomosis are able to form collaterals with a high reliability, but these procedures are often difficult to technically perform in small children, and complications, when they occur, tend to be severe. Indirect procedures, such as encephalo-duro-arterio-synangiosis (EDAS), encephalo-myo-synangiosis (EMS), and encephalo-myo-arterio-synangiosis (EMAS) etc., are safe and easy and also successfully form collaterals especially in children with moyamoya disease. However, there are a few drawbacks with such procedures. They do not always form sufficient collaterals. The area where the original EDAS using the posterior branch of the superficial temporal artery can be done is also limited. Moreover, because the area covered by each single procedure is small, the collateral formation obtained by a single procedure is not always satisfactory. For these reasons we developed a fronto-temporoparietal combined indirect bypass procedure for child patients in order to overcome these problems. This multiple combined indirect procedure can cover a wider area of the ischemic brain through the EMAS in the frontal and the EDAS and EMS in the temporo-parietal regions. It is also safe and easy to perform, and one or two of these three procedures form sufficient collaterals with a relatively high reliability. This technique is described and the results are presented.