Interventions in Acute Intracranial Surgery: An Evidence-Based Perspective.

From a pathophysiological point of view, early neurosurgical treatment seems essential to prevent secondary brain injury and has been stated as the "time-is-brain" concept. However, the question immediately rises: "Is there an optimal time window for acute intracranial neurosurgical interventions?" In neurosurgery, treatment modality has been studied far more extensively than timing to surgery ("time-to-surgery"). The majority of acute intracranial neurosurgical interventions are carried out for traumatic brain injury and hemorrhagic or ischemic stroke. Current guidelines for traumatic brain injury, spontaneous intracerebral hemorrhage, aneurysmal subarachnoid hemorrhage, and middle cerebral artery infarction are reviewed and lessons learned from the randomized controlled trials mentioned are discussed. In acute intracranial neurosurgical interventions, "delayed consent" procedures could play an important role for this field of research. Whether there is an optimal time window for acute intracranial neurosurgical interventions seems difficult to be answered with randomized controlled trials referred to in the current guidelines. Observational designs, such as comparative effectiveness research, and special statistical techniques, may provide a better understanding in the optimal "time-to-surgery."