Commentary

Remote postoperative epidural hematoma (EDH) is a rare and unusual phenomenon. Supratentorial EDH is usually reported as a possible complication of posterior fossa surgery as well as spinal surgery.[1,2] Authors reported a case of postoperative parietal EDH and contralateral subdural hygroma after the surgery of fourth ventricle tumor in a 13-year-old female patient. There is still no satisfactory explanation of the mechanism of this complication. The possible etiology of EDH is: Coagulopathy, misuse of pins for head fixation, incomplete hemostasis of the dura mater or diploe, poorly controlled arterial blood pressure, failure to place adequate dural suspensions, and intraoperative hemodynamic changes. However, presumably large cerebrospinal fluid (CSF) loss during the surgery and sudden lowering of intracranial pressure may be the main causes in the pathogenesis of remote postoperative EDH.[3,4] Negative intracranial pressure caused by rapid CSF leakage can produce inner suction, which will facilitate dura separation from the internal table of the cranium, and bleeding from dural and/or diploe veins.[5] The adhesions between the dura mater and internal cranial vault are less in younger age than in adults or in the elderly, which is why postoperative EDH have a evident predilection in adolescents.[6] In present case, rapid perioperative CSF loss was caused by stripping of the dura from the right parietal bone and EDH formation.[7] On the contralateral side, displacing brain caudally was not followed by dura stripping and an empty space between the brain and cranial vault was compensatory filled by CSF.