Case Report: Stepwise quantitative assessment of intraoperative intracranial pressure after perforation, craniotomy, dural incision, and hematoma removal in acute subdural hematoma.

Introduction: Severe traumatic brain injury often requires emergency surgical intervention such as craniotomy or decompressive craniectomy. The timely reduction of intracranial pressure (ICP) is critical for improving neurological outcomes. However, limited quantitative data exist regarding how each surgical step of perforation, craniotomy, dural incision, and hematoma removal contributes to ICP reduction in acute subdural hematoma. Case presentation: A man in his 40s developed bilateral acute subdural hematomas (right/left: 8/7 mm thick) following a fall. His initial Glasgow Coma Scale score was 3. Because the bilateral hematomas were relatively thin, we initially opted for medical management, inserting an ICP sensor into the right frontal lobe for continuous monitoring. Despite initial neurocritical care, ICP remained elevated (45 mmHg). Serial imaging revealed the progression of cerebral edema and midline shift. Emergent decompressive craniectomy on the left side was therefore performed under continuous ICP monitoring. ICP was recorded at each surgical step: single burr hole placement (42 mmHg), partial craniotomy (39 mmHg), complete craniotomy (20 mmHg), dural incision (14 mmHg), and hematoma evacuation (9 mmHg). Each step produced a measurable decrease in ICP. Despite aggressive management, the patient's condition deteriorated; he died on hospital day 21. Conclusion: The present case illustrates the stepwise contribution of each surgical intervention to ICP reduction in acute subdural hematoma. Although the clinical outcome was unfavorable, these quantitative data provide valuable insights into the decompressive effect of each surgical step. These findings underscore the importance of prompt and progressive surgical management of severe traumatic brain injury with elevated ICP.