Outcome of Superficial Temporal Artery-to-Middle Cerebral Artery Bypass in Appropriately Selected Patients with Acute Ischemic Stroke

Background: Endovascular treatment is the preferred treatment for acute ischemic stroke (AIS) due to main artery steno-occlusive disease, but it has temporal and technical limitations. Moreover, there is no established treatment for progressive stroke. Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass is sometimes considered as a treatment option. Objective: The objective of this paper is to review the treatment outcomes of patients with AIS undergoing urgent STA-MCA bypass. Methods and Material: This was a retrospective study including 32 patients diagnosed with AIS treated with urgent STA-MCA bypass at our facility. The patients had small infarct volumes and a large diffusion-perfusion mismatch. Results: New ischemic lesions in postoperative diffusion-weighted images were detected in 15 patients (46.9%), but only four (12.5%) developed paralysis. Hyperperfusion occurred in nine patients (28.1%), and five (15.6%) had bypass occlusion at 1 week. Delayed wound healing were found in four patients (12.5%). Neurological outcome was measured 3 months after onset: Manual Muscle Testing (MMT), 3-5 in 27 patients (84.4%); modified Rankin scale (mRS), 0-2 in 17 patients (53.1%); and 0-3 in 26 patients (81.3%). Prognosis was better in patients who underwent surgery after 24 h of stroke onset (mRS, 0-2 in 56.0% cases and 0-3 in 88.0% at 3 months). Statistical analyses revealed that MMT before surgery had a significant association with favorable outcomes (P = 0.041). Conclusions: Urgent STA-MCA bypass for progressive stroke may result in a good prognosis if the right patients are selected and may play an important role in cases treated 24 h after onset in whom endovascular treatment is ineffective.