Factors affecting the collateral ingrowth from the superficial temporal artery after Encephalo-Duro-Arterio-Synangiosis in adult patients with Moyamoya disease

Background: Multiple factors have been proposed to affect the vessel ingrowth from the superficial temporal artery (STA) after Encephalo-Duro-Arterio-Synangiosis (EDAS). Methods: This retrospective single-center analyses included patients with Moyamoya Disease (MMD) undergoing EDAS from January 1st, 2013, to December 31st, 2023. Evaluated variables included demographic characteristics, clinical presentation, technical details, modified Rankin Scale (mRS) scores, and radiographic outcomes. Univariate and multivariate analysis was performed to identify factors favoring the ingrowth of collaterals from the STA. Results: Forty adult patients with MMD, most commonly females (77.5 %) with a median age of 48, underwent 56 EDAS. The most common initial presentations were ischemic events (75.0 %), followed by hemorrhagic events (27.5 %) and seizures (7.5 %). Digital angiography performed at a median of 13.7 months post-procedure revealed collateral growth from the STA in 78.6 % of cases, with a Matsushima grade A identified in 35.7 % of the revascularized hemispheres. Univariate analysis showed more collaterals in patients with a larger preoperative STA diameter (p=0.035), higher Suzuki grades (p=0.021) and longer angiographic follow-ups (p=0.048). Patients with occlusion of the internal carotid artery (ICA; p<0.01), middle cerebral artery (MCA; p<0.01), or anterior cerebral artery (ACA; p<0.01) also had more collateral ingrowth. Multivariate analysis revealed that ICA occlusion (OR=6.54; 95 % CI=1.03-41.48) and ACA occlusion (OR=6.52; 95 % CI=1.02-41.67) as predictors of collateral ingrowth from the STA. Conclusion: ICA and ACA occlusion were associated with success after EDAS. Longer follow-ups and larger STA demonstrated significant association on univariate analysis, but lost significance after adjusting for other procedural characteristics.