Between 2008 and 2021, a total of 120 patients underwent at least one neurosurgical procedure for a spontaneous ICH. After excluding patients with insufficient neuroradiological data, 114/120 patients were analyzed (Table 1). At the time of hemorrhage, the median age was 61 (range: 25-89) years and patients presented with a median GCS of 6 (range: 3-15). Most ICHs were classified as deep location (66/114, 58%), with intraventricular hemorrhage being present in 82/114 (72%) patients. In 70/114 (61%) patients, a median midline shift of 8 mm (range: 4-20 mm) was evident. Surgeries for clot removal alone, EVD insertion alone or EVD insertion with clot removal were performed in 44/114 (39%), 46/114 (40%) and 24/114 (21%) patients, respectively.
Hydrocephalus at presentation
Hydrocephalus at presentation, measured by the Evans’ Index, occurred in 41/114 (36%) patients. When comparing patients presenting with or without hydrocephalus, no significant differences in sex (p=0.44), age (p=0.14) and GCS (p=0.48) could be observed (Table 1). Hydrocephalus occurred significantly more often in patients with infratentorial hemorrhage (p=0.037) and purely intraventricular bleeding (p=0.044) with an OR of 3 (1.1-8.2) and 0.3 (0.27-0.44). The presence of IVH (p=0.02) and DM2 (p<0.001) were associated with acute hydrocephalus with an OR of 3.2 (1.2-8.7) and 7.1 (2.3-21.5), respectively. Furthermore, patients with hydrocephalus showed significantly higher IVH (p<0.001) and CSF (p<0.001) volumes, and significantly lower ICH volumes (p<0.001, Table 1), compared to patients without hydrocephalus.
EVD treatment
In our study population, 70/114 (57%) patients received an EVD. Between patients with and without an EVD, no statistically significant differences concerning sex (p=1.00) and age (p=0.22) were seen (Table 1).
The EVD placement was significantly more often performed in patients with a lower median GCS at presentation (p<0.05), signs of hydrocephalus at presentation (p<0.001, OR=16.2, 4.6-57.4), IVH (p<0.001, OR=7.4, 3-18.6), thalamic ICH (p<0.001, OR=14.9, 1.9-116.1), infratentorial ICH (p=0.037, OR=4.1, 1.1-14.8), higher IVH (p<0.001) and CSF volume (p<0.001), lower ICH volume (p<0.001) and with a higher IVHS (p<0.001), as shown in Table 1. In patients with an EVD, the median volume of IVH, ICH and intraventricular CSF was 22.1cm³ (range: 0-99.3cm³), 21.1cm³ (0-97.2cm³) and 40.3cm³ (2-205.2cm³), respectively.
There was no statistically significant difference in the median total hemorrhage volume (IVH+ICH) in patients with an EVD (52.4cm³, range: 1-135.2cm³) compared to patients without an EVD treatment (51.7cm³, range: 6.1-110.1cm³, p=0.93). However, the median ratio between the total hemorrhage volume and intraventricular CSF was significantly lower in patients with an EVD (1.1, range: 0-63.3) compared to patients who did not receive an EVD (2.7, range: 0.3-14.2, p<0.001).
In 21/70 (30%) patients, EVD placement was performed bilaterally. Patients who received an EVD bilaterally, had a significantly higher median IVH (38.9cm³, range: 3.3-99.3cm³ vs. 17.5cm³, range: 0-83.1cm³; p<0.001) and lower ICH volume (8.4cm³, range: 0-47.1cm³ vs. 23.9cm³, range: 1-97.2cm³, p<0.001) compared to patients after a unilateral EVD placement. Moreover, patients received significantly more often a bilateral EVD after a deep hemorrhage (18/21, 86%, p=0.016), thalamic ICH (10/21, 48%, p=0.015) and purely IVH (3/21, 14%, p=0.024).
Shunt treatment
After excluding patients, who died within 30 days (n=18/120, 15%), 99/120 patients could be evaluated for shunt dependency (Table 2). Of those, 57 (58%) patients underwent treatment with an EVD. Shunt implantation was performed in 11/99 (11%) patients. Between patients with and without a shunt in place, no statistically significant differences concerning sex (p=0.53), age (p=0.53), GCS at presentation (p=0.59) and IVH (p=0.50) was encountered (Table 2).
In shunted patients, the median volume of IVH, ICH and intraventricular CSF was 25.2cm³ (range: 0-51.4cm³), 21cm³ (0-53.3cm³) and 61.5cm³ (28.9-205.2cm³), respectively. Shunt implantation was significantly more often performed in patients with hydrocephalus at presentation (p<0.001, OR=10.7, 2.2-53.1), thalamic ICH (p=0.026, OR=4.8, 1.3-18.1), cerebellar ICH (p=0.036, OR=5.02, 1.2-20.5), lower ICH volume (p=0.03), higher CSF volume (p<0.001) and a higher IVH distribution in the third ventricle (p=0.03) as shown in Table 2 and Table 3. Furthermore, higher IVH volumes (25.2cm³, range: 0-51.4cm³) revealed no significant difference between patients needing a CSF-shunt and those without (4.9cm³, range: 0-99.3cm³, p=0.07).
There was no statistically significant difference in the median total hemorrhage volume (IVH+ICH) in shunted patients (39.6cm³, range: 12.2-83.2cm³), compared to patients without needing a CSF-shunt (50.7cm³, range: 1-135.2cm³, p=0.328). However, the ratio between the total hemorrhage volume and intraventricular CSF was significantly lower in shunted patients (0.6, range: 0.1-2.3), compared to patients without a CSF-shunt (2.2, range: 0-63.3, p=0.005).
Differences in EVD treatment between patients with and without a shunt
No patient without an EVD in the acute phase developed a secondary hydrocephalus necessitating the implantation of a CSF-shunt. Differences in EVD treatment duration or the amount of drained CSF per day between patients with and without a CSF-shunt were analyzed in 51/57 (90%) patients, due to insufficient data in the remaining 6 patients. There was no significant difference in the median amount of drained CSF/day between shunted (140ml, range: 66-224ml) and non-shunted patients (118ml, range: 0-239ml, p=0.330). However, shunted patients had a significantly longer median EVD treatment duration (25 days, range:10-46 days) compared to non-shunted patients (14 days, range:1-66 days, p=0.002). Furthermore, there was no significant difference in revision surgeries for an EVD placement between patients with and w/o a shunt (p=0.07) (Table 4).
Prediction of shunt dependency
To predict later shunt dependency, we generated a logistic regression model including IVH, ICH and intraventricular CSF based on all 99 patients and established the following formula:
-0.005*ICH + 0.029*IVH + 0.036*intraventricular CSF
The ROC model demonstrated a sensitivity of 82% and a specificity of 65% to predict the necessity for a shunt at a cutoff-value of 1.9 with an AUC of 0.835 (Figure 2).