The importance of encephalo-myo-synangiosis in surgical revascularization strategies for moyamoya disease in children and adults.

OBJECTIVE

The optimal surgical procedure (direct, indirect, or combined anastomosis) for management of moyamoya disease is still debated. We evaluated the outcome of our broad area revascularization protocol, the Tokyo Daigaku (The University of Tokyo) (TODAI) protocol, analyzing the relative importance of direct, indirect, and combination revascularization strategies to identify the optimal surgical protocol.

METHODS

The TODAI protocol was used to treat 65 patients with moyamoya disease (91 hemispheres, including 48 in 29 childhood cases collected during 1996-2012). The TODAI protocol combined direct superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis with indirect revascularization using encephalo-myo-synangiosis (EMS) for patients ≥10 years old or indirect revascularization using encephalo-duro-arterio-synangiosis (EDAS) with EMS for patients ≤9 years old. Clinical outcome was evaluated retrospectively. Digital subtraction angiography was performed for postoperative evaluation of revascularization in 47 patients (62 hemispheres; 27 adults and 35 children). Based on the relative contribution of additional flow from each revascularization path, 4 revascularization patterns were established.

RESULTS

The mean follow-up period was 90 months in children and 72 months in adults. Perioperative complications were seen in 4 of 48 operations in children and 1 of 43 operations in adults. Except for 1 child with recurrent transient ischemic attacks and 1 adult with intracerebral hemorrhage, the patients showed excellent clinical outcomes. Postoperative digital subtraction angiography evaluation showed that in STA-MCA anastomosis + EMS cases (34 hemispheres; 25 adults and 9 children), STA-MCA anastomosis provided greater revascularization than EMS (STA-MCA anastomosis > EMS) in 7 hemispheres, the opposite was true (STA-MCA anastomosis < EMS) in 14 hemispheres, an equivalent contribution to revascularization (STA-MCA anastomosis ≈ EMS) was present in 12 hemispheres, and no functioning anastomosis was present in 1 hemisphere. In cases of EDAS + EMS (28 hemispheres; 2 adults and 26 children), all hemispheres showed revascularization: EDAS was dominant to EMS (EDAS > EMS) in 1 hemisphere, the opposite (EMS > EDAS) was true in 14 hemispheres, and EDAS was equivalent to EMS (EDAS ≈ EMS) in 13 hemispheres. EMS plus direct or indirect anastomosis is an effective surgical procedure in adults and children.

CONCLUSIONS

The TODAI protocol provided efficient revascularization and yielded excellent results in preventing strokes in patients with moyamoya disease with very few complications. EMS had a main role in revascularization in each of the combined techniques.