Intracranial pressure trends and clinical outcomes after decompressive hemicraniectomy in malignant middle cerebral artery infarction.

Background: Malignant middle cerebral artery infarction (MMI) is associated with a high incidence of severe disability and mortality. Decompressive hemicraniectomy has become a recognized treatment that can improve the prognosis for patients if performed within a certain time window. Nevertheless, despite this intervention, a mortality rate of approximately 20-40% persists following the surgery. The trends and clinical implications of intracranial pressure (ICP) in these situations remain unclear. We aimed to investigate whether intracranial pressure (ICP) trends are associated with clinical outcomes in patients undergoing decompressive hemicraniectomy for MMI.

Methods: This retrospective cohort study included consecutive patients with MMI who underwent decompressive craniectomy and received ICP monitoring after surgery. Using a linear mixed model, we categorized the patients into ICP increase and decrease groups based on the ICP values obtained over 192 h. We then compared the proportion of 3-month favorable outcomes (modified Rankin Scale of 0-4) and mortality rates between these groups.

Results: Of 112 MMI patients who underwent decompressive hemicraniectomy, 66 (58.9%) received invasive ICP monitoring. ICP monitoring was performed for a median of 146.5 h (IQR 72.5-181.8). Among the 66 patients, 37 (56.1%) were in the ICP increase group, and 29 (43.9%) were in the ICP decrease group. During the monitoring period, the initial monitored ICP and peak ICP did not significantly differ between the ICP increase and decrease groups. However, the ICP trend was significantly different between the two groups (P < 0.001). In multivariable logistic regression analyses, the ICP increase group had a significantly lower proportion of 3-month favorable outcomes compared to the ICP decrease group (adjusted OR 0.11; 95% CI, 0.01-0.59; P = 0.019), and significantly higher mortality in the intensive care unit (adjusted OR 6.98; 95% CI, 1.37-54.6; P = 0.031).

Conclusions: In MMI patients, continuous ICP monitoring could be useful for detecting those with an increasing ICP trend that may be associated with unfavorable clinical outcomes.