gms | German Medical Science

Objective: The initial burden of brain edema has recently been proposed to be an important predictor of delayed cerebral infarction (DCI) in patients with aneurysmal subarachnoid hemorrhage (aSAH). In the present study, we aim to further analyze the pathophysiological relevance of brain edema by comparing the association of edema and DCI in patients before vs. after cisternal lavage – an effective method for clearing the amount of blood in the subarachnoid cisterns – was implemented.

Methods: All consecutively treated aSAH patients between 10/2010 and 10/2019 were included. 68 patients with early mortality (<96h) were excluded. The primary endpoint -Delayed Cerebral Infarction- was assessed using the Vergouwen criteria. Cerebral edema was assessed using the Subarachnoid Hemorrhage Early Brain Edema Score (SEBES) on the initial head CT scan. Neurological outcome was determined using the modified Rankin Scale (mRS) 6 months after ictus. Multiple covariates were taken into consideration and uni- and multivariate logistic regressions were performed for both BEFORE (no cisternal lavage available) and AFTER (cisternal lavage available) cohorts. Odds ratio, regression coefficients and 95% confidence intervals were calculated. Pearson’s correlations Chi-squared test was performed to evaluate the association between DCI and mRS.

Results: A total of 524 (m/f ratio 1:2.06) patients with aSAH were included in our study. Mean age of patients was 57.1 years (SD: ±13.2). Cisternal lavage was introduced in 10/2015 and was applied in 31.6% (n=70 of 221) patients considered at high risk for DCI. DCI was detected in 19.1% of patients BEFORE cisternal lavage was implemented (n=60/313) vs. 8.6% (n=19/221) in the AFTER cohort. SEBES Score ≥ 2 was positively associated with the development of DCI (p<0.05) in the BEFORE cohort. This association was no longer present AFTER implementation of cisternal lavage. A higher blood amount (Hijdra Score) and WFNS score, as well as presence of aSAH-associated intracerebral hemorrhage were also risk factors for the development of DCI. There was a strong positive association between DCI and poor outcome (mRS 4-6) at 6 months (Chi-squared test p<0.001).

Conclusion: The current study shows that the predictive association of edema and DCI is lost, when the root cause of DCI, i.e. the blood in the basal cisterns, is effectively removed. Thus, we conclude that brain edema might be regarded as an indicator of the severity of the bleed but is not causally related to the development of DCI.

Figure 1 [Fig. 1]