A hematoma is a localized collection of blood that pools outside of the blood vessels, often following a traumatic injury. While many small hematomas are reabsorbed by the body over time, a larger collection can pose a significant danger. When a hematoma forms in a confined space, such as within the skull, it creates a mass that compresses surrounding tissues. Hematoma evacuation, or surgical drainage, relieves this dangerous pressure and prevents severe neurological damage.
Understanding the Need for Intervention
Surgical evacuation is necessary when the volume of pooled blood creates a mass effect on nearby structures. In the rigid confines of the skull, this expanding mass directly increases the intracranial pressure (ICP), which can restrict blood flow to the brain. This pressure increase is poorly tolerated, and without intervention, it can quickly lead to tissue compression and herniation, where brain matter shifts across anatomical boundaries.
The resulting neurological deficits, such as weakness, confusion, or loss of consciousness, are consequences of this compression. The urgency for intervention is largely determined by the hematoma’s location and the speed of its growth. Acute hematomas, which form rapidly, demand immediate evacuation due to the sudden rise in ICP. Conversely, chronic hematomas develop slowly over weeks, allowing the brain time to partially adapt, but they still require drainage once they become symptomatic or reach a concerning size.
Preoperative Imaging and Assessment
The decision to proceed with hematoma evacuation is based on both clinical presentation and diagnostic imaging. The Computed Tomography (CT) scan is the primary tool, providing immediate, detailed images of the skull and brain tissue. The CT scan allows medical professionals to measure the hematoma’s volume, its maximum thickness, and the extent of any “midline shift,” which is the displacement of the brain’s central structures.
Quantitative metrics are often used to guide the surgical decision, such as a hematoma thickness exceeding 10 millimeters or a midline shift greater than 5 millimeters. Imaging also determines the age of the blood collection, which affects its consistency—liquid in chronic cases versus clotted in acute cases—informing the surgical approach. This evidence is correlated with the patient’s neurological status, assessed using the Glasgow Coma Scale (GCS). The GCS is a standardized tool scoring responses based on eye opening, verbal response, and motor response. A low GCS score, especially 8 or less, indicates a severe brain injury and necessitates urgent surgical decompression.
Surgical Approaches to Hematoma Removal
The method chosen for hematoma removal is dictated by the blood’s consistency, size, and location within the brain’s coverings. For acute, clotted hematomas causing significant mass effect, a craniotomy is performed. This involves a large scalp incision followed by the temporary removal of a section of the skull bone, known as a bone flap. Once the dura mater is opened, the surgeon uses suction and irrigation to remove the solid blood clot. The bone flap is either replaced and secured with plates or left out (a craniectomy) if significant brain swelling is anticipated.
For chronic subdural hematomas, where the blood is typically more liquid, burr hole drainage is preferred. The surgeon drills one or two small perforations, or burr holes, into the skull over the collection site. A small opening is made in the dura, and a catheter is inserted to wash out the liquid hematoma. A temporary drain is often left in place for up to 48 hours to ensure drainage of any remaining fluid.
Deep-seated blood collections, such as intracerebral hematomas, may be treated with stereotactic or endoscopic aspiration. This minimally invasive approach uses computer-guided navigation to precisely direct a thin catheter through a small burr hole to the center of the hematoma. The blood is then aspirated through the catheter. This technique aims to minimize damage to the surrounding healthy brain tissue by avoiding a large incision and direct manipulation.
Postoperative Recovery and Rehabilitation
Following evacuation, the patient is transferred to the Intensive Care Unit (ICU) for monitoring of neurological status and vital signs. Immediate post-operative care focuses on managing the intracranial environment, including keeping the head of the bed elevated to assist in controlling swelling. If a drain was placed during surgery, it is monitored for output and usually removed within the first couple of days. A follow-up CT scan confirms the extent of hematoma removal and checks for any immediate complications, such as re-accumulation of blood.
The long-term path to recovery depends on the patient’s pre-operative neurological condition and the extent of the initial damage. Rehabilitation begins early and is a multidisciplinary effort involving physical, occupational, and speech therapists. Physical therapy focuses on regaining strength, mobility, and balance, which are often affected by the initial brain compression. Occupational therapists help patients relearn daily living activities, while speech therapists address communication or swallowing difficulties. Full recovery may take months, and long-term monitoring for potential complications, such as seizure activity, is required.