Burr hole drainage is a surgical procedure used to remove a blood clot near the brain. These blood clots are known as subdural hematomas because they form under the dura, which is the protective covering of the brain.
Hematomas usually require removal because they can compress the brain tissue and cause life-threatening complications. In certain cases, a traditional open surgery, known as a craniotomy, may be necessary.
The surgeon will make a small incision in the scalp, then use a special surgical drill to create a small perforation in the skull. The dura is cut open to reveal the hematoma. Irrigation is employed to rinse the area out and to remove the blood clot. Once that has been accomplished, the surgeon will close the incision.
Sometimes a drain is left behind on the surface of the brain to help prevent a reaccumulation of the blood.