Survey of Available Literature and Meta-Analyses on Chronic Subdural Hematoma

Chronic subdural hematoma (CSDH) is an encapsulated collection of blood and fluid on the surface of the brain. It is a common condition, especially in elderly patients, with an incidence of 58 cases per 100 000 people per year in patients over 65 years of age, a mortality rate of about 2%, and a recurrence rate ranging from 11.7% to 28% despite surgical and medical treatments. Due to the high incidence of CSDH, a vast amount of literature exists on the various medical and surgical aspects. Moreover, the literature contains meta-analyses analyzing different techniques, medical therapies, and factors associated with prognoses. Herein, the available literature and meta-analyses on different aspects of CSDH are reviewed in order to provide a rapid review of the best evidence regarding this condition. Twelve meta-analyses comparing the effects of different surgical and/or medical treatments on various different clinical outcomes were analyzed. Strong evidence was found that: (1) burr-hole craniostomy and twist-drill craniostomy are both efficacious in treating CSDH; (2) drainage placement is associated with better clinical outcomes and significantly lower recurrence rates; (3) antithrombotic drugs are significantly associated with a higher recurrence rate; and (4) in case of need of reoperation, open craniotomy is associated with better outcomes compared with minimally invasive procedures. Further studies are needed to clarify the role of corticosteroids and the best timing of the resumption of antithrombotic drugs after CSDH evacuation.