MATERIAL and METHODS: This cross-sectional study was conducted in Southern Iran during a 7-year period from 2009 to 2016. All the patients with Moyamoya Disease (confirmed with digital substraction angiography) who underwent microsurgical revascularization (extracranial-intracranial bypass or synangiosis) were included. All the patients were followed for at least 1 year and the outcome was measured using the Glasgow outcome scale (GOS) and modified Rankin scale (MRS).

RESULTS: Overall we included 13 patients with 14 involved hemispheres undergoing direct and indirect revascularization. The mean age of the patients was 20.6±17.5 (ranging from 0.5 to 55) years and there were 5 (38.4%) males and 8 (61.6%) females. We did not have any unfavorable outcome defined as mortality and persistent vegetative state. We performed 12 (85.7%) superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and 2 (14.3%) encephalo-myo-synangiosis (EMS) procedures. The symptoms improved in 7 (53.8%) patients and remained as the preoperative course in 5 (38.5%) patients. Only 1 (7.7%) patient developed immediate postoperative vasospasm and brain swelling, and was managed successfully with decompressive craniectomy and subsequent cranioplasty (GOS=5, MRS=0).

CONCLUSION: This is the first study to report the safety, efficacy and outcome of the direct (STA-MCA bypass) and indirect (EMS) revascularization in patients with MMD in the Iranian population. As the prevalence of MMD is low in Iranian population, the experience and technique remains in its infancy and further advancements in the field is required. Keywords : Extracranial-intracranial bypass, Iran, Moyamoya Disease, Revascularization, Synangiosis