STA-MCA Bypass for Moyamoya Vasculopathy: Early Experience and Outcomes from a National Referral Centre

Moyamoya vasculopathy is a progressive cerebrovascular disorder requiring surgical revascularisation. In Malaysia, experience with cerebral bypass has been limited. This study evaluated early outcomes of superficial temporal artery-middle cerebral artery (STA-MCA) bypass at a national referral centre.

A retrospective study was conducted on patients undergoing STA-MCA bypass between January 2017 and December 2025. Functional outcomes were assessed using the modified Rankin Scale (mRS), while cerebral perfusion and bypass patency were evaluated using computed tomography (CT) perfusion and CT angiography or digital subtraction angiography. Statistical analyses included Fisher's exact test, Mann-Whitney U test, and Spearman correlation.

A total of 74 cerebral bypass procedures were performed, including 50 for moyamoya vasculopathy, with 37 cases analysed. Median age was 43 years with female predominance (54%). Single-barrel bypass was performed in 84% of cases, with 100% final intraoperative patency. Perfusion improved in 85% of patients and graft patency in 94%. At three months, 95% achieved good functional outcome (mRS 0 to 2). Greater surgeon experience was associated with shorter operative duration (ρ = -0.463, P = 0.0039). Preoperative antiplatelet withholding was also associated with reduced operative duration (P = 0.0109) without adverse impact on clinical or radiological outcomes. No variables were significantly associated with adverse outcomes (P > 0.05).

STA-MCA bypass achieves excellent clinical and radiological outcomes in a maturing neurovascular programme. These findings support the development of structured revascularisation services and inform perioperative management strategies in a national referral setting.