Efficacy of Occipital Artery-Encephaloduroarteriosynagiosis for Posterior Circulation Ischemia in Moyamoya Disease.

BACKGROUND AND

OBJECTIVES

Posterior cerebral artery (PCA) involvement in Moyamoya disease (MMD) is associated with increased risk of cerebral infarction and poor prognosis. Direct bypass using the occipital artery (OA-PCA bypass) is an established approach; however, it is technically challenging and carries risks of surgical complexity and wound-related complications, and whether indirect bypass can provide favorable hemodynamic outcomes in posterior circulation remains unclear. We investigated the clinical utility and effectiveness of indirect bypass using occipital artery-encephaloduroarteriosynangiosis (OA-EDAS) in patients with MMD associated with PCA stenosis.

METHODS

We retrospectively evaluated the medical data of 11 patients (13 hemispheres) with MMD and PCA stenosis who underwent OA-EDAS between 2008 and 2023. Ten hemispheres underwent simultaneous OA-EDAS after anterior direct/indirect bypass surgery, whereas 3 hemispheres underwent OA-EDAS only. Cerebral perfusion and cerebrovascular reactivity were evaluated using [123I]-iodoamphetamine single-photon emission computed tomography 6 months after surgery. Surgical outcomes, postoperative complications, and long-term follow-up data were analyzed.

RESULTS

Single-photon emission computed tomography indicated improved cerebral blood flow in the PCA territory in 5 hemispheres (38.5%). Cerebrovascular reactivity improved in 6 of 9 hemispheres (66.7%). No new ischemic events were detected during a mean follow-up period of 61.5 ± 52.4 months. During follow-up, angiography confirmed the development of collateral circulation in all cases and disappearance or reduction in the extent of choroidal anastomosis in 75% of cases. No wound-related complications occurred. OA-EDAS was performed within a short operative period, even by a surgeon with intermediate skills, and was technically easy.

CONCLUSION

OA-EDAS may be a safe and effective indirect revascularization treatment for PCA stenosis associated with MMD, resulting in satisfactory perfusion improvement and minimal surgical morbidity. Its technical simplicity, short operative time, and preservation of native OA flow may render it a valuable alternative to direct OA-PCA bypass.