The Role of Early Superficial Temporal to Middle Cerebral Artery Bypass Revascularization Surgery in Middle Cerebral Artery-Territory Strokes: A Systematic Review Study.

Background: To systematically summarize and critically review the available literature regarding the functional outcome of the urgent superficial temporal artery to the middle cerebral artery (MCA) bypass surgery in stroke patients associated with MCA lesions. Methods: The current systematic review was conducted and reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. Medline (PubMed), ISI Web of Science, Scopus, and google scholar (manually searches) were systematically searched up to August 2021. The eligibility criteria were defined as all the patients who had MCA-territory strokes due to MCA/intradural internal carotid artery lesions that underwent same-admission superficial temporal artery-MCA bypass surgery. The strokes with cervical internal carotid artery and anterior cerebral artery lesions/strokes were excluded. The checklists produced by the US National Heart Lung and Blood Institute were used for quality assessment. Demographic variables, clinical findings, National Institutes of Health Stroke Scale scores, the time interval between symptoms to surgery, imaging results, endovascular treatments, surgical notes, mortality rate, follow-up findings, modified Rankin scale scores, and all reported medical records were extracted and analyzed with SPSS software (ver. 23). Results: The initial search yielded 3050 records, and 13 articles met the inclusion criteria and entered this systematic review. A total of 165 patients were pooled for data analysis. Nine studies had data regarding neurological deficits before and after surgery. Except for 5 patients, the National Institutes of Health Stroke Scale score after the operation was the same or better than the preoperative score. Eleven out of 17 patients in 3 studies showed early neurological improvement (a decrease in National Institutes of Health Stroke Scale score of ≥4 points at 3 days) after bypass surgery. Functional outcome was stated in 10 studies. Overall, a good functional outcome (modified Rankin scale=0-2) was achieved in 9 out of 21 (42.1%) patients at discharge and in 44 out of 59 (74.5%) patients at 3 months follow-up. Lower age was associated with favorable outcomes. Long-term graft patency was excellent in 99.5% of patients. Postoperative hematoma and mortality (all noncranial) rates were 3% and 3.6%, respectively. Conclusion: The current study suggests that early superficial temporal artery-MCA revascularization should be considered an available option in younger patients (<60-year-old) with MCA territory strokes who fail medical treatment.