Background: Thoracic Endovascular Aortic Repair has been widely performed to treat various thoracic aortic pathologies. However, stent-graft placement in the thoracic aorta may result in left subclavian artery coverage, potentially leading to ischemic complications. The role of the left subclavian artery revascularization procedure to prevent ischemic complications remains controversial. Therefore, we conducted a systematic review and meta-analysis to identify ischemic outcomes in patients who underwent thoracic Endovascular Aortic Repair with or without left subclavian artery revascularization. Methods: A systematic search through electronic databases, including PubMed, Ovid Medline, and Cochrane, was conducted to identify relevant studies. The outcome parameters were left arm ischemia, stroke, and spinal cord ischemia. Risk ratio (RR) and Confidence Interval (CI) of 95% were measured and reported. Results: A total of 11,386 patients were identified from 22 studies. Patients who underwent left subclavian artery revascularization had lower risk of left arm ischemia (RR 0.25, 95% CI 0.09–0.68; P = 0.0006; I2 = 71%), lower risk of stroke (RR 0.52, 95% CI 0.30–0.88; P = 0.02; I2 = 70%), and lower risk of spinal cord ischemia (odds ratio OR 0.72, 95% CI 0.55–0.95; P = 0.02; I2 = 0%) between the 2 groups. Conclusions: Revascularization procedure in patients with left subclavian artery coverage during thoracic Endovascular Aortic Repair is associated with a lower risk of left arm ischemia, stroke, and spinal cord ischemia. Left subclavian artery revascularization should be performed in anatomically high-risk patients. High-quality studies are needed to validate the outcomes.