Effectiveness of Ipsilateral Stroke Prevention Between Conservative Management and Indirect Revascularization for Moyamoya Disease in a North American Cohort

Background: Few reports have compared surgical intervention with conservative treatment for moyamoya disease (MMD) in non-Asian cohorts. This study describes the effectiveness of follow-up stroke prevention by indirect revascularization relative to conservative management in a Northeast United States study population.

Method: We retrospectively reviewed records of patients with MMD at our institution from 1990 to 2014. Baseline characteristics and follow-up results including subsequent ipsilateral strokes were collected, and compared between an indirect revascularization group and a conservatively treated group on a per-hemisphere basis.

Results: A total of 94 patients with 184 hemispheres were included. The average age was 23.9 ± 18.1 years, with 76.6% (n = 141) being female. Racial distribution comprised white (n = 75, 40.8%), African-American (n = 57, 31.0%), Asian (n = 30, 16.3%), and other (n = 22, 12.0%). Eighty-three hemispheres (45.1%) presented with ipsilateral stroke and 54 (29.3%) with ipsilateral TIA. Management strategies included either conservative management (51.1%) or indirect bypass (48.9%). Patients who were male (P < 0.001), on baseline antiplatelets (P = 0.043), or with speech disturbance (P = 0.002) were more likely to receive indirect revascularization. Patients with headache history were more likely to be treated conservatively (P = 0.046). History of ipsilateral stroke was borderline associated with indirect bypass (P = 0.058). During a follow-up period of 6.37 ± 5.81 years, the annual risk of stroke for indirect revascularization group was 0.93% and 2.70% for the conservative group. Multivariate analysis found that increasing age (P = 0.029), posterior cerebral artery involvement (P = 0.040), and conservative treatment (P = 0.048) were associated with follow-up stroke.

Conclusion: Our results suggests that indirect revascularization provides symptom relief and lower risk of stroke during follow-up compared with conservative management. Indirect revascularization should be considered for symptomatic MMD patients with a low surgical risk profile in a similar patient population.