Indirect Revascularization for Non–Moyamoya Disease Anterior Circulation Arterial Steno-occlusion: Clinical Features, Surgical Treatment, and Medium-Term Outcomes in Adults

Background Symptomatic anterior arterial steno-occlusion is often associated with neurofunctional deficits or a high risk of recurrent stroke or both. Although both medical and endovascular treatments are useful and suitable, few studies have investigated the continued use of indirect encephaloduroarteriosynangiosis (EDAS) bypass in patients with non–moyamoya disease ischemia. We retrospectively investigated clinical features, surgical treatments, and medium-term outcomes of indirect revascularization for patients with non–moyamoya disease anterior circulation arterial steno-occlusion in China. Methods EDAS without burr holes was performed in 51 adult patients with cerebral ischemic events and diagnosed nonmoyamoya anterior circulation arterial steno-occlusion. Preoperative, postoperative, and follow-up neurologic status was evaluated using the National Institutes of Health Stroke Scale; changes on angiography and perfusion-weighted magnetic resonance imaging were evaluated. Results Unilateral EDAS was performed in 48 patients, and bilateral EDAS was performed in 3 patients. Four patients experienced complications before hospital discharge; only 23 patients underwent follow-up angiograms. Of the 51 patients, 44 (86.3%) exhibited improved muscle strength; 21 of 23 patients (91.3%) with follow-up angiography data exhibited evidence of new visible branches from the superficial temporal artery or middle meningeal artery or both. Preoperative and postoperative perfusion-weighted magnetic resonance imaging was performed for 5 patients. Despite clinical improvement in all patients, only 2 exhibited hemodynamic improvement. Conclusions Indirect revascularization may be safe and effective for improving blood flow to the ischemic region following nonmoyamoya anterior circulation arterial steno-occlusion, especially in patients with residual postinfarction neurologic deficits. Our study demonstrates that improvements in ischemic symptoms after EDAS correspond to neovascularization from the superficial temporal artery or middle meningeal artery in ischemic brain areas.