Efficacy and Safety of Middle Meningeal Artery Embolization for Patients with Chronic Subdural Hematoma: A Systematic Review and Meta-Analysis

BackgroundChronic subdural hematoma (CSDH) is characterized by the collection of blood beneath the dura mater. Traditional treatments involve surgical drainage of the hematoma, but recurrence rates can be high. A highly vascularized neo-membrane irrigated by the middle meningeal artery (MMA) may be involved in CSDH re-accumulation. ObjectiveWe conducted a systematic review and meta-analysis of studies that compared the efficacy and safety of MMA embolization to conventional treatment alone for CSDH. Material and MethodsA systematic search of PubMed, Embase Ovid, and ClinicalTrials.gov identified observational and randomized clinical studies comparing MMA embolization to conventional treatment for chronic subdural hematoma. The efficacy outcomes were hematoma recurrence and good functional outcome (as defined by a modified Rankin Scale score (mRS) of 0-2). Safety outcomes were the rate of major complication and mortality. Heterogeneity among studies were evaluated using the I2 statistic. Analyses were conducted using Cochrane Review Manager software, with risk ratios (RR) and 95% confidence intervals (95% CI) presented for key outcomes. Absolute risk reduction (ARR, 95% CI) 1000 patients were also calculated using GRADEpro software. ResultsThe analysis included data from 13 studies (4 RCTs and 9 observational studies) with a total number of 2960 patients (35.3% in the MMA group and 64.7% in the conventional treatment group). Compared to conventional treatment, MMA embolization decreased risk of hematoma recurrence by 60% (13 studies, RR=0.40, 95% CI 0.25-0.63; I2=50%), for an absolute effect of 119 fewer events/1000 patients (95% CI 70-149), with similar risk of major complications (9 studies, RR=0.82, 95% CI=0.54-1.25) and mortality risk (13 studies, RR=0.90, 95% CI=0.54-1.51). In subgroup analyses by study type, pooled results from RCTs showed similar direction effects as those from observational studies for both efficacy and safety outcomes. ConclusionMMA embolization in CSDH management is a safe and effective approach for CSDH.