[Three cases of chronic subdural hematoma developing after direct aneurysmal surgery (author's transl)].

Three cases of chronic subdural hematoma developing after direct aneurysmal surgery were presented. All patients were males and heavy drinkers. There was no history of head injury after craniotomy. In two of the three cases, the angiography was performed on the 12th postoperative day. An avascular area was already revealed on the postoperative angiograms, but there were no disorders at that time. The intervals between the aneurysmal surgery and the onset of symptoms of chronic subdural hematoma ranged from about two to three months. In this report, the diagnostic criteria for the chronic subdural hematoma resulted from intracranial surgery were also discussed with a consideration on the pathogenesis of this condition.