Association between neoangiogenesis after first and second indirect bypass in moyamoya disease

Abstract Background The research on neoangiogenesis after indirect bypass for moyamoya disease (MMD) evaluated by using digital subtraction angiography (DSA) is limited. Our study objective was to investigate association between neoangiogenesis after first indirect bypass and second indirect bypass in MMD.Methods All consecutive inpatients with MMD who received indirect bypass at Beijing Tiantan Hospital, Capital Medical University from January 2011 through December 2017 were screened. Bilateral neoangiogenesis was evaluated on lateral views and anteroposterior views by using DSA .Results Twenty-two patients (44 hemispheres) were included in this study. After a median 7.5 months DSA follow-up, On lateral views, 9 (40.9%) hemispheres had grade A, 8 (36.4%) hemispheres had grade B, and 5 (22.7%) hemispheres had grade C after the first procedures; 11 (50.0%) hemispheres had grade A, 7 (31.8%) hemispheres had grade B, and 4 (18.2%) hemispheres had grade C after the second surgery. On anteroposterior views of ECA, 2 (9.1%) hemispheres had level 0, 3 (13.6%) had level 1, 6 (27.3%) had level 2, and 11 (50.0%) had level 3 after the first procedures; 2 (9.1%) hemispheres had level 0, 2 (9.1%) had level 1, 6 (27.3%) had level 2, and 12 (54.6%) had level 3 after second operation. Neovascularization after second operation was strongly associated with the neovascularization after first operation on lateral views (r s =0.770; p=0.000) and the anteroposterior views (r s =0.548; p=0.008).Conclusion Neovascularization after second indirect bypass was strongly associated with neovascularization of first indirect bypass.