This systematic review and meta-analysis aimed to summarize the current literature on mechanical thrombectomy (MT) in nonagenarians and to provide updated clinical evidence of its feasibility, effectiveness, and safety in nonagenarians. PubMed, EMBASE, the Cochrane Library, and Web of Science were searched for relevant randomized controlled trials and observational studies that reported the clinical outcomes of nonagenarians with acute ischemic stroke after undergoing mechanical thrombectomy. Risk of bias was assessed using different scales. I2 statistic was used to evaluate the heterogeneity of the results, while meta-regression and sensitivity analyses were performed to investigate the source of heterogeneity. Thirteen studies and 657 patients were included. The estimated rate of successful revascularization was 80.82% (95% confidence interval [CI]: 77.48-83.97%), and the rate of favorable outcome (modified Rankin score [mRS] 0-2) was 21.60% (95% CI: 13.81-30.41%). The rate of good outcome (mRS score 0-3) was 23.08% (95% CI: 18.88-27.55%). The estimated risk of death during hospitalization was 20.55% (95% CI: 15.93-25.55%), while the mortality rate at 3 months was 44.38% (95% CI: 33.66-55.36%). The rate of intracranial hemorrhage (ICH) occurrence was 12.84% (95% CI: 5.27-22.68%), while the rate of symptomatic intracranial hemorrhage (sICH) was 3.52% (95% CI: 1.67-5.85%). The rate of hospital-related complications was 26.93% (95% CI: 10.53-47.03%). MT in nonagenarians demonstrated a high rate of successful revascularization. Conversely, the rate of futile revascularization is high with a low functional independence proportion. Therefore, MT should not be indiscriminately advocated in nonagenarians. Satisfactory results require careful selection of patients. Further high-quality studies are needed to clarify the selection algorithm.
Keywords: Acute ischemic stroke; Mechanical thrombectomy; Meta-analysis; Nonagenarian; Systematic review.