Combined Direct and Indirect Revascularization for Contralateral Moyamoya Disease Progression: A Surgical Video Technical Note

Introduction: Moyamoya disease is a chronic, progressive cerebrovascular disorder characterized by bilateral steno-occlusive changes of the terminal internal carotid arteries and compensatory formation of fragile collateral vessels, exposing patients to a persistent risk of ischemic and hemorrhagic stroke.1 Disease progression to the initially unaffected hemisphere is well recognized, so patients treated unilaterally require close hemodynamic follow-up of the contralateral side2. So, the objective of this study was to describe, through an illustrative surgical video, the technique of combined direct (superficial temporal artery–middle cerebral artery, STA–MCA) and indirect (pericranial synangiosis) revascularization performed for new-onset contralateral hemodynamic compromise in a patient with previously, unilaterally treated Moyamoya disease. Case Report: A 16-year-old patient who had undergone right-sided STA–MCA bypass with indirect revascularization in January 2024 presented with perfusion imaging showing persistent prolongation of the mean transit time within the left anterior and middle cerebral artery territories, consistent with hemodynamic impairment3. Left-sided combined revascularization was performed: Doppler-guided mapping and dissection of the frontal and parietal branches of the superficial temporal artery, craniotomy, an end-to-side STA–MCA anastomosis onto an M4 cortical branch using 9-0 polypropylene microsutures with a fish-mouth donor configuration, and indirect revascularization with the preserved parietal STA branch and a vascularized pericranial flap. Results: Intraoperative indocyanine green videoangiography confirmed immediate bypass patency, with adequate filling of the donor artery and opacification of the recipient cortical vessel.4 Postoperative three-dimensional CT angiography demonstrated a patent STA–MCA anastomosis and an appropriately positioned indirect revascularization construct, with no intraoperative or immediate postoperative complications. Conclusion: Combined direct and indirect revascularization provided immediate flow augmentation together with the potential for progressive neovascularization, representing a safe and reproducible strategy for hemodynamically significant, progressive Moyamoya disease, consistent with contemporary outcome data favoring combined over isolated indirect techniques in both adult and pediatric cohorts.5,6