Traumatic Acute Subdural Haematoma: Management and Outcome

Traumatic acute subdural haematomas (ASDHs) are common pathological entity in neurosurgical practice . The frequency of (ASDHs) has been proposed as approximately 10-20% of patients admitted with traumatic brain injury(TBI) .Approximately two -thirds of patient with TBI undergoing emergency cranial surgery have an acute subdural haematoma evacuated . Two common causes of traumatic ASDH: accumulation of blood around parenchymal laceration , usually frontal and temporal lobes and there is usually severe underlying brain injury .The second cause is surface or bridging vessel torn from cerebral acceleration - deceleration during violent head motion . These haematomas have been historically associated with high mortality rate (between 40-60%)(1).This high mortality rate has been attributed to the characteristic of haematoma itself , due to the primary insults to the brain like brain parenchymal injury , and to the secondary insults like hypoxia and hypotension in severe head injury patients .

Theoretically ,intracranial hypertension due to ASDH may lead to transtentorial cerebral herniation and secondary ischemic injury of the brain.CT scan is main and most informative investigatory aid in diagnosis of traumatic ASDH. The criteria used to select patients for non - operative management are clinical stability or improvement during the time from injury to evaluation at hospital , haematoma thickness less than 10 mm and mid line shift less than 5 mm in the initial CT. Surgery is indicated if on CT 1- ASDH with thickness > 10mm. or 2- Mid line shift >5mm.on CT 3- ASDH with thickness <10 mm and midline shift <5mm on CT should undergo surgical evaluation if (a) GCS drop by >_ 2 point from injury to admission .(b) and or pupils are asymmetric or fixed and dilated (7). Time of surgery for ASDH is matter of controversy. As general principle ,when surgery for ASDH is indicated it should be done as soon as possible . Regarding evacuation of acute subdural haematoma, procedures vary from single burrhole evacuation to craniotomies and decompressive procedures .Some advocated ASDH evacuations by decompressive craniectomy with dural - slits .