Introduction: Decompressive hemicraniectomy is a life-saving procedure for patients with malignant middle cerebral artery (MCA) infarction. However, substantial numbers of patients still die despites hemicraniectomy due to refractory intracranial hypertension. The role of monitoring of intracranial pressure (ICP) in patients who underwent hemicraniectomy is largely unknown.
Hypothesis: We hypothesized that ICP during the immediate post-hemicraniectomy period may be an early indicator of effectiveness of decompressive hemicraniectomy.
Methods: We included 25 patients 1) who underwent hemicraniectomy for malignant MCA infarction, 2) whose ICP probes were inserted during the hemicraniectomy, and 3) whose ICP was measured hourly during the first postoperative day. Non-contrast brain CT was obtained within the first hour after hemicraniectomy. Midline shift at levels of septum pellucidum and pineal gland was measured on CT. Level of consciousness was evaluated with Glasgow coma scale 24 hours after hemicraniectomy. Survival status was assessed at six months. We analyzed the relationship between ICP, midline shift, Glasgow coma scale, and survival.
Results: Initial ICP was correlated with mean ICP (p<0.001) and maximal ICP (p<0.001) during the first post-operative day. Initial ICP was associated with midline shift at the septum pellucidum (p=0.009), midline shift at the pineal gland (p=0.012), and Glasgow coma scale (p=0.025). Sixteen (64.0%) patients survived at six months. In Cox proportional hazard model, elevated initial ICP was associated with survival for six months (hazard ratio, 1.130; 95% CI, 1.032 - 1.237; p=0.008).
Conclusion: ICP measured during the immediate post-hemicraniectomy period was associated with midline shift, level of consciousness, and survival at six-months in patients with malignant MCA infarction. Our findings suggest that early ICP may be an indicator of effectiveness of decompressive hemicraniectomy and a predictor of long-term survival after hemicraniectomy for malignant MCA infarction. Further studies are necessary to explore clinical implications of our findings with regard to triggering additional and timely interventions after a hemicraniectomy.