Subdural Evacuation

What Is Subdural Evacuation?

Subdural evacuation is a surgical procedure to remove a subdural hematoma (SDH) – a pooling of blood on the brain. Subdural hematomas are categorized as acute, subacute, and chronic. An SDH may be caused by trauma but can also be spontaneous or may be caused by a procedure, such as lumbar puncture. Other non-blood accumulation, such as hygromas and post infectious fluid collections, also may benefit from evacuation.

Types of Subdural Hematoma

An acute subdural hematoma shows symptoms within the first 24 hours and requires emergency surgery. Subacute hematomas occur within 2 to 10 days after head trauma. A chronic subdural hematoma can be caused by a seemingly minor head injury and may have no immediate symptoms. Slow bleeding from the injury will build up until it reaches a critical stage, sometimes weeks after the initial injury. It is often seen in the very young or the very old as both groups have a larger subdural space.

Depending on their size, type, and growth rate, subdural hematomas may be accessed by a craniotomy or burr hole and then evacuated. Removal of small subdural hematomas can be done with a small catheter at the bedside. Large hematomas can require a craniotomy in which a surgeon opens the skull and dura and removes the blood clot with irrigation or suction.