Treatment of Moyamoya disease in the adult population with pial synangiosis

Surgical treatment of moyamoya disease in the adult population commonly uses direct revascularization, the superficial temporal artery (STA) to middle cerebral artery (MCA) bypass (STA-MCA). Pial synangiosis, a method of indirect revascularization, has been used in adult patients with moyamoya when STA-MCA bypass was not technically feasible. Although the effectiveness of pial synangiosis has been well described in children, only limited reports have examined its role in adult patients with moyamoya disease. In this study the authors report on their experience with pial synangiosis revascularization for this population. The authors reviewed the clinical and radiographic records of all adult patients (≥ 18 years of age) with moyamoya disease who underwent cerebral revascularization surgery using pial synangiosis at a single institution. From 1985 to 2010, 66 procedures (6 unilateral, 30 bilateral) were performed on 36 adult patients with moyamoya disease. The mean age at surgery was 28.3 years, and 30 patients were female. Twenty-eight patients (77.8%) presented with transient ischemic attacks (TIAs), 24 (66.7%) with stroke, and 3 (8.3%) with hemorrhage. Preoperative Suzuki stage was III or higher in 50 hemispheres (75.8%) and 3 patients had undergone prior treatments to the affected hemisphere before pial synangiosis surgery. Clinical follow-up was available for an average of 5.8 years (range 0.6-14.1 years), with 26 patients (72.2%) followed for longer than 2 years. Postoperative angiography was available for 24 patients and 46 revascularized hemispheres, and 39 (84.8%) of the 46 hemispheres demonstrated good collateral formation (Matsushima Grade A or B). Postoperative complications included 3 strokes, 5 TIAs, and 2 seizures, and there was no hemorrhage during the follow-up period. One patient required additional revascularization surgery 8 months after pial synangiosis. Pial synangiosis is a safe and durable method of cerebral revascularization in adult patients with moyamoya and can be considered as a potential treatment option for moyamoya disease in adults.