gms | German Medical Science

Objective: The main purpose of the present study was to predict the development of hydrocephalus after subarachnoidal hemorrhage (SAH) by quantitative measurement of the extravasated blood volume in the basal cisterns.

Method: A retrospective analysis was performed that included all patients treated in the Department of Neurosurgery due to an aneurysmatic SAH from the 1^st January 2010 until the 31^st December 2011. All patients included in the study needed an initial CT scan in digital form not older than 3 days after bleeding. The blood volume was measured from the extracted digital CT scans separate for each slice that demonstrated visible blood by a computer assisted volumetric analysis. The patients were stratified into 3 groups: (1) no hydrocephalus, (2) acute hydrocephalus and (3) chronic hydrocephalus. To compare the blood volume leading to hydrocephalus as well as for death we used a t-test. A general linear model (GLM) was used to describe the correlation between the different forms of hydrocephalus.

Results: A total number of 64 patients, 53 (82.2%) female and 11 (17.8%) male, were collected. The mortality in our study was 20.3% (n=13). In total, 40 (62.5%) patients developed a hydrocephalus, 6 (9.38%) of them developed a chronic hydrocephalus, which was treated by shunt implantation. The mean blood volume in the basal cisterns in patients who developed a chronic hydrocephalus was 9.6ml (±4.2) compared with 9.0ml (±5.5) in patients with acute hydrocephalus and 4.1ml (±3.0) in patients developing no hydrocephalus. The mortality-corrected blood-volume in patients with chronic hydrocephalus was 9.6ml (± 4.2), in patients with acute hydrocephalus 7.0ml (± 4.2) and in patients without hydrocephalus 3.7ml (± 2.3). There was a significant difference between patients with or without hydrocephalus (p<0.0001). With regard to the mortality, the mean blood-volume in patients who survived was 5.9ml (± 4.0) compared to 12.5ml (± 6,3; p=0.0004) in patients who died in the consequence of the disease.

Conclusions: The blood volume in the basal cisterns is a predictor for developing a hydrocephalus but also a predictor for mortality. Furthermore, there is a significant difference of blood volume between patients who developed a chronic or no hydrocephalus.