Jumah et al. conducted a systematic review and meta-analysis (MA) in compliance with the PRISMA guidelines to evaluate the efficacy and safety of Middle meningeal artery embolization (MMAE) compared with conventional treatments for refractory or chronic subdural hematoma (cSDH). Databases were searched up to March 2019. Using a random-effects model, meta-analyses of proportions and risk differences were conducted recurrence, need for surgical rescue, and complications.

Eleven studies (177 patients) were included. The majority (116, 69%) were males with a weighted mean age of 71 + -19.5 years. A meta-analysis of proportions showed treatment failure to be 2.8%, the need for surgical rescue 2.7%, and embolization-related complications 1.2%. A meta-analysis of risk-difference between embolized and non-embolized patients showed a 26% (p < 0.001, 95% CI 21%-31%, I2 = 0) lower risk of hematoma recurrence in MMAE. Similarly, in the embolized group, the need for surgical rescue was 20% less (p < 0.001, 95% CI = 12%-27%, I2 = 12.4), and complications were 3.6% less (p = 0.008, 95% CI 1%-6%, I2 = 0) compared to conventional groups.

Although MMAE appears to be a promising treatment for refractory or cSDH, drawing definitive conclusions remains limited by the paucity of data and small sample sizes. Multicenter, randomized, prospective trials are needed to compare embolization to conventional treatments like watchful waiting, medical management, or surgical evacuation. More extensive research on MMAE could begin a new era in the minimally invasive management of cSDH ¹⁾.

The goal of a study was to review the evidence on MMAE in cSDH to assess its safety, feasibility, indications and efficacy. Court et al. performed a systematic review of the literature according to PRISMA guidelines using multiple electronic databases. This search yielded a total of 18 original articles from which data were extracted. A total of 190 patients underwent MMAE from which 81.3% were symptomatic cSDH. Over half (52.3%) of the described population were undergoing antithrombotic therapy. Most (83%) procedures used polyvinyl alcohol (PVA) particles and no complications were reported regarding the embolization procedures. Although the definition of resolution varied among authors, cSDH resolution was reported in 96.8% of cases. MMAE is a feasible technique for cSDH, but the current body of evidence does not yet support its use as a standard treatment. Further studies with a higher level of evidence are necessary before MMAE can be formally recommended ²⁾.

Three double-arm studies comparing embolization and conventional surgery groups and 6 single-arm case series were identified and analyzed. Hematoma recurrence rate was significantly lower in the embolization group compared with conventional treatment group (2.1% vs. 27.7%; odds ratio = 0.087; 95% confidence interval, 0.026-0.292; P < 0.001; I2 = 0%); surgical complication rates were similar between groups (2.1% vs. 4.4%; odds ratio = 0.563; 95% confidence interval, 0.107-2.96; P = 0.497; I2 = 27.5%). Number of patients with modified Rankin Scale score >2 in the embolization (12.5%) versus conventional treatment (9.1%) group showed no statistical difference (P = 0.689). A composite hematoma recurrence rate of 3.6% was found after summing the 6 case series. Composite recurrence and complication rates in the embolization cohorts of the double-arm studies and the case series were lower than literature values for conventional surgical treatments.

MMA embolization is a promising treatment for chronic subdural hematoma. Future randomized clinical trials are needed ³⁾.