Flow-Augmentation STA-MCA bypass for Acute Ischemic Stroke with Diffusion-Perfusion Mismatch: Clinical and...

While mechanical thrombectomy (EVT) is the established standard for acute ischemic stroke (AIS), a significant unmet clinical need remains for patients in whom EVT is unsuccessful, technically infeasible, or contraindicated. This study aimed to evaluate the safety and potential efficacy of increased flow augmentation via superficial temporal artery-middle cerebral artery (STA-MCA) bypass, primarily utilizing the double-barrel technique, as a rescue strategy for patients with AIS and significant diffusion-perfusion mismatch.

We retrospectively analyzed 22 AIS patients with identifiable diffusion-perfusion mismatch who underwent emergency STA-MCA bypass between June 2020 and November 2023. The majority of patients underwent surgery within 24 hours of symptom onset or early neurological deterioration (END). Outcomes were assessed through radiological stabilization (reduction in Tmax > 6s volume), neurological improvement (National Institutes of Health Stroke Scale [NIHSS] score), and functional recovery (modified Rankin Scale [mRS] score at 3 months).

Graft patency was achieved in 100% of cases, with double-barrel bypass performed in 19 patients (86.4%) to increase flow augmentation. Postoperatively, the median hypoperfusion volume (Tmax > 6s) decreased significantly from 116 mL to 6 mL (p < 0.001), suggesting attenuation of infarct progression. The median NIHSS score improved from 9 at baseline to 5 at 14 days post-surgery (p < 0.001). At 3 months, 15 patients (68.2%) achieved a favorable functional outcome (mRS 0-2). No symptomatic or radiologically evident intracranial hemorrhage or procedure-related hematoma occurred despite the high rate (77.3%) of perioperative antithrombotic therapy.

STA-MCA bypass may be a feasible rescue strategy and appears safe in carefully selected AIS patients lacking other reperfusion options. With physiology-driven, imaging-based selection and timely surgical intervention, this approach may be associated with meaningful hemodynamic restoration, early perfusion improvement, and subsequent clinical stabilization in the acute phase. In this context, the double-barrel technique may represent a feasible flow-augmentation strategy in selected patients with substantial hemodynamic compromise.