Traumatic Acute Subdural Hematoma

Acute subdural hematoma (SDH) represents a major clinical entity in traumatic brain injury (TBI), diagnosed on computed tomography (CT) as extraaxial, hyperdense, crescent lesion between the dura, and brain parenchyma. Between 12% and 29% of patients admitted with a severe traumatic brain injury (TBI) have an acute SDH. When combining all patients with TBI, 11% present with an SDH. Acute traumatic SDH has been traditionally considered a lesion that should be treated surgically, although some might be approached conservatively. Because of its complex pathophysiology, mortality of acute SDH has been remaining high, in spite of advances in emergency medical systems, diagnostic modalities, and treatment techniques.¹

Theoretically, intracranial hypertension due to acute SDH may lead to transtentorial cerebral herniation and secondary ischemic injury of the brain. The purpose of surgery is to release from herniation and to reduce secondary ischemic injury minimally. Thus, acute SDH causing significant mass effect, which may be effectively reduced by surgery, is supposed to be an indication for surgery. In general, initial surgical indication may be based on the patients GCS score, pupillary examination, and CT findings. Neurological deterioration and/or increase in ICP may also be an important factor in delayed decision.²

The choice of surgical procedures may depend on the surgeon’s expertise, training, neurological status of patients, duration from deterioration, pre-operative radiological findings, degree of intraoperative brain swelling, and availability of operating theater. In principle, the purpose of surgery is to release brain from intracranial hypertension to suppress secondary injury minimally. Thus, large craniotomy with hematoma evacuation may be principle. When intra- and/or post-operative brain swelling is strongly expected, decompressive craniectomy may be suitable. However, as it has been known that bony decompression result in apparent exacerbation of edema, the superiority of decompressive craniectomy to craniotomy is still controversial.^{3, 4}