Superficial temporal artery-middle cerebral artery bypass combined with encephalo-duro-myo-synangiosis in treating moyamoya disease: surgical techniques, indications and midterm follow-up results.

Background: Surgical interventions for moyamoya disease include direct and indirect revascularizations. This study aimed to evaluate the therapeutic effect of superficial temporal artery-middle cerebral artery bypass combined with an indirect revascularization procedure, encephalo-duro-myo-synangiosis, in the treatment of moyamoya disease.

Methods: From October 2005 to November 2009, we performed this combined revascularization procedure in 111 patients with different types and stages of moyamoya disease. The superficial temporal artery, middle meningeal artery and the deep temporal artery were evaluated for individualized surgical planning in these cases. The integrity of the deep temporal artery and the middle meningeal artery network, and the pre-existing spontaneous anastomoses of the distal branches of the external carotid artery with the cortical arteries were well preserved. The mean follow-up time was 72.5 months, all clinical and radiological data were retrospectively reviewed.

Results: A total of 198 stomas were performed in 122 hemispheres, all remaining patent until the last follow-up. The encephalo-duro-myo-synangiosis resulted in extensive anastomoses of the deep temporal artery (100%), the middle meningeal artery (90.9%), and the sphenopalatine artery (39.8%) with the cortical arteries, respectively. The superficial temporal artery, deep temporal artery, and the middle meningeal artery were significantly thickened in 88 patients as determined by digital subtraction angiography at follow-up. The relative cerebral blood flow increased significantly within one week after the operation. At 6 months post the operation, the relative cerebral blood flow was further increased by 15.5% from the gradual formation of anastomoses as a result of indirect revascularization. Transient ischemic attacks were effectively reduced or totally arrested. The neurological deficits significantly improved in 37 patients, with the National Institutes of Health Stroke Scale scores lowered by 2-8. There was no rehemorrhage in hemorrhagic moyamoya disease patients.

Conclusion: This study showed that the superficial temporal artery-middle cerebral artery bypass combined with encephalo-duro-myo-synangiosis can achieve good therapeutic effect in the treatment of moyamoya disease.