Abstract MP47: Clinicoradiological Outcomes of Surgical Revascularization for Moyamoya Disease With Minimum 10-Year Follow-Up
Introduction: The long-term progression of disease and recurrence rate of symptomatic events after surgical revascularization for moyamoya disease (MMD) are unknown. Method: Patients with MMD operated on between 1991 and 2009 were prospectively enrolled into the departmental database. Results: 230 revascularization (87% combined direct and indirect and 13% indirect alone) procedures were performed on 129 patients for the treatment of MMD with a long-term bypass patency rate of 98%. Unilateral presentation was identified in 39 (30.2%) compared to 90 (69.8%) with bilateral MMD. Posterior circulation (PC) involvement was identified in 34 (26.4%) patients. Over a median follow-up period of 13 years (range 10-26 years), 15 (38.5%) patients experienced radiographic progression of unilateral disease and 14 (10.9%) experienced PC radiographic progression. Delayed surgical revascularization of the untreated contralateral anterior circulation was performed on 11 (28.2%) patients due to symptomatic progression of disease. Progression of PC disease occurred only in patients with PC involvement upon presentation. Aside from those with unilateral progression, fourteen additional patients (10.9%) experienced delayed cerebrovascular accidents (CVAs), 8 of which were ischemic and 6 were hemorrhagic strokes. Twelve delayed CVAs occurred in a previously revascularized hemisphere while one occurred in an un-diseased hemisphere from a micro pseudoaneurysm. Repeat revascularization was performed in 6 patients while 4 were managed conservatively and 4 were deceased. Relative to baseline presenting mRS, 92.2% of patients were improved or unchanged at 10 year follow-up. On multivariate regression, progression of the PC predicted the development of delayed CVA (Odds ratio 8.1, 95% CI 1.1-59.2) while pre-operative stroke (Odds ratio 3.4, 95% CI 1.2-9.8) presentation and progression of disease was predictive of 10-year outcome (Odds ratio 4.0, 95% CI 1.5-10.6). Conclusion: Good functional outcomes over a median follow-up period of 13 years support the strategy of revascularization for MMD patients. Disease progression of the posterior circulation is common and may reduce pial-pial collaterals resulting in delayed CVAs.