Significant recurrent chronic subdural hematoma i.e. requiring repeat operative drainage at six months after the primary operation Six months after primary burr hole evacuation of chronic subdural hematoma [clinicaltrials_resource:7a58e1854a94d1e3d09caf967403ddbb]

Burr hole drainage of chronic subdural hematoma under general or local anesthesia without the subsequent placement of a subdural drain.

Significant recurrent chronic subdural hematoma i.e. requiring repeat operative drainage at six months after the primary operation Six months after primary burr hole evacuation of chronic subdural hematoma [clinicaltrials_resource:7a58e1854a94d1e3d09caf967403ddbb]

Burr hole drainage of chronic subdural hematoma under general or local anesthesia without the subsequent placement of a subdural drain.