1068. Direct vs. Indirect Revascularization Surgery in Adult Moyamoya Disease: A 20-Year, Single Institutional Experience

Authors: Anadjeet Singh Khahera, BS; Justin Sim, BA; Evangeline Reyes-Pastorella; Brandon Christophe, BA; E. Connolly, MD (New York, NY)

Introduction: Current standard of care for adult Moyamoya disease (MMD) involves direct or indirect revascularization surgeries that bypass the ICA narrowing. This is a single-institution’s experience with revascularization surgeries for MMD. Methods: A retrospective chart review was conducted on MMD patients undergoing direct and indirect bypass surgeries at Columbia University Medical Center from 1998-2018. Direct bypass involved superficial temporal artery to middle cerebral artery (STAMCA) connection, while indirect bypass utilized encephalodurosynangiosis (EDAS). Extracted data included demographics, presentation, and complications. Functional outcome was assessed with Glasgow Outcome Scale (GOS) at discharge, 30-days, 90-days, and 1-year. Results: A total of 92 MMD patients underwent revascularization surgery with 87 EDAS (124 hemispheres) and 5 STAMCA (7 hemispheres) procedures. Female:Male ratio was 2.5:1, average age was 40, and Caucasian patients composed 46% of the cohort. 85% presented with ischemic symptoms and 7% with hemorrhage. All patients had pre-operative angiograms to confirm the MMD diagnosis. Perioperative complications following EDAS included 4 ischemic events and 4 pressure-dependent TIAs. There were no perioperative complications following STAMCA. Following EDAS, there was a steady, statistically significant improvement in GOS from each of the four follow-up time points, while STAMCA improvement occurred from discharge to 3mo and 12mo, but not from discharge to 1mo. Of the 72 EDAS patients with long-term follow-up, 76% demonstrated improvement in GOS from baseline, while 80% of STAMCA patients showed improved GOS. Conclusion: The Columbia MMD cohort matches other North American cohorts with demographic data (Caucasian, middle-aged, female) and presentation (ischemic). EDAS patients demonstrated steady improvement in functional outcome, while STAMCA patients improved in delayed fashion. The delayed improvement can be explained by Columbia protocol indicating STAMCA for MMD patient with full ICA/M1 occlusion patients. In this cohort, both EDAS and STAMCA demonstrated an ability to help resolve MMD symptoms and improve functional outcome.