Multiple combined indirect procedure for the surgical treatment of children with moyamoya disease. A comparison with single indirect anastomosis and direct anastomosis.

Considering three different bypass procedures now in use, (single indirect nonanastomotic bypass procedure, multiple combined indirect (MCI) nonanastomotic procedure and direct anastomosis), the authors attempted to identify the most appropriate bypass procedure for treating ischemic-type moyamoya disease in children. The authors performed three procedures (the original encephaloduroarteriosynangiosis [EDAS] alone, the frontotemporoparietal combined indirect bypass procedure, and the superficial temporal artery--middle cerebral artery [STA-MCA] anastomosis with encephalomyosynangiosis [EMS]) on 72 hemispheres in 50 patients with pediatric moyamoya disease. Analyses were then performed to compare postoperative collateral vessel formation found on angiograms, complications, and clinical improvements. Postoperative collateral formations were observed in more than two-thirds of the MCA distribution after the EDAS alone, the MCI procedure, and the direct anastomosis in 44%, 52%, and 74% of the surgically treated hemispheres, respectively. In addition, frontal encephalomyoarteriosynangiosis of the MCI bypass procedure formed collateral vessels of the anterior cerebral artery distribution in 94% of the treated hemispheres. Postoperatively, clinical symptoms resolved in 56%, 63%, and 74% of the treated sides 1 year after EDAS alone, MCI procedure, and the direct anastomosis, respectively. One patient suffered a minor stroke after EDAS alone, two patients developed epidural hematomas after the MCI procedure, and one patient suffered a major stroke and one patient a minor stroke after undergoing direct anastomosis. The direct anastomosis procedure was found to result in the best postoperative collateral vessel formation and clinical improvement. However, the single and multiple combined indirect nonanastomotic bypass procedures were found to be safer than direct anastomosis. Furthermore, the frontotemporoparietal combined indirect bypass procedure caused the formation of collateral circulation not only in the MCA but also in the ACA distribution. Based on analysis of these findings, the authors recommend the MCI procedure as the appropriate surgical procedure in the treatment of children with moyamoya disease, although the best treatment is the STA-MCA anastomosis with EMS when feasible.