Failure Rates of Conservative Management of Minimally Symptomatic Chronic Subdural Hematoma: A Systematic Review and Meta-Analysis

Background: Conservative treatments for minimally symptomatic chronic subdural hematoma (cSDH) are debated, with surgery as the primary option. Objective: To assess failure rates of a conservative approach for management of cSDH. Methods: We searched PubMed, SCOPUS, Web of Science, and ClinicalTrials.gov for studies on conservative management of cSDH and analyzed the data using R (version 4.1.2). Results: A total of 35 studies including 2095 patients were analyzed: 950 (45%) of the patients were in the observation group, 671 (32%) in the corticosteroid group, 355 (17%) in the atorvastatin group, 43 (2%) in the mannitol group, 52 (2.5%) in the tranexamic acid group, and 24 (1.1%) in the etizolam group. Our pooled analysis showed that 19.82% of patients required rescue surgery (95% confidence interval [CI]: 12.98% to 26.66%, P < 0.0001). The overall pooled risk ratio (RR) for the effect of interventions on the need for rescue surgery was 0.2424 (95% CI: 0.1577 to 0.3725, Iˆ2 = 90.5%, P < 0.0001). Subgroup analysis showed varied effects: observation group (RR = 0.3482, 95% CI: 0.1045 to 1.1609, Iˆ2 = 94.0%), corticosteroids (RR = 0.2988, 95% CI: 0.1671 to 0.5344, Iˆ2 = 90.8%), atorvastatin (RR = 0.1609, 95% CI: 0.0985 to 0.2627, Iˆ2 = 53.2%), mannitol (RR = 0.0370, 95% CI: 0.0009 to 1.5244), and tranexamic acid (RR = 0.0585, 95% CI: 0.0026 to 1.2924). Conclusions: The rate of rescue surgery in conservatively managed cSDH patients remains high. Corticosteroids or atorvastatin demonstrates some potential benefit in reducing the failure rate but collective effectiveness is unknown.