• subdural

Chronic subdural hematoma (cSDH) is a common neurological disease which is increasing in prevalence with an estimated 60 000 new diagnoses of cSDH per year expected by 2030.1 ,2 Embolization of the middle meningeal artery (MMA) for the treatment of cSDH has rapidly progressed from an intriguing concept to a relatively routine procedure over the past 2 years. Initial case reports from the first decade of the 2000s were bolstered by larger case series in the years that followed.2–5 These studies led to a larger series from Ban et al, who reported remarkable success rates for this procedure in patients undergoing embolization either as an adjunct to surgical evacuation or as a stand-alone treatment when compared with historical controls.6 Several larger, retrospective, self-adjudicated case series have reported similarly optimistic outcomes.2 MMA embolization would thus appear to offer a minimally invasive, technically straightforward, relatively safe procedure that potentially obviates the need for open surgery and/or decreases the rate of recurrence.

If proven safe and effective, MMA embolization could fundamentally change the standard of care for the management of cSDH. Prospective randomized controlled trials (RCTs) will be essential if this vision is to become a reality. While cSDH as a pathophysiology might seem straightforward, the disease and its management have proven to be extraordinarily complex. Moreover, defining the comparative “effectiveness” of treatment strategies for a disease in which relatively unambiguous radiological findings may be associated with an array of clinical presentations is nuanced. Designing a trial is further complicated when viewed through the lens of the informative prior data, which are largely derived from self-adjudicated retrospective case series, many of which have used inconsistent endpoints to assess safety and effectiveness. This comment will address some of the challenges involved with designing a pragmatic RCT of MMA embolization for …