Extracerebral non-haemorrhagic expansive complications of intracranial surgery.

Extracerebral non-haemorrhagic collections of fluid and air causing significant impairment in the early period after intracranial surgery have received very little attention in the literature. Twenty-five fluid collections have been encountered, of which 17 appeared after intracerebral operations and were often in communication with the ventricular system. After extracerebral explorations supratentorial fluid collections accumulated in the Sylvian fissure or between the brain surface and the falx or tentorium in 5 cases, while a collection of fluid occurred infratentorially in the cerebellopontine angle in three cases. Intracranial air collections have been described more often after craniotomies, particularly after drainage of chronic subdural haematomas, but have not been recognized after intracerebral removal of tumours or in cases where exploration has been performed beyond the limits of the craniotomy in the presence of high intracranial pressure. Improvement after reoperation occurred most promptly in the cases with fluid collections, while additional factors often seem to play a more significant role in the cases with postoperative intracranial air.