Objective: Lumbar drainage (LD) of cerebrospinal fluid (CSF) is a simple way of clearing subarachnoid hemorrhage (SAH) and reducing the risk of delayed cerebral ischemia (DCI). We focused on Fisher grade 3 SAH with or without minimal intraventricular hemorrhage (IVH; Graeb score ≤5), which has a lower risk of cerebellar tonsillar herniation during LD. The aim of this study was to test the efficacy of LD with respect to reducing the risk of DCI in this patient group.

Methods: The authors retrospectively reviewed the medical records of 107 patients with Fisher grade 3 SAH with or without minimal IVH, admitted to two hospitals from 2013 to 2019. Patients were retrospectively divided into two groups: study group receiving standard therapy plus LD, or control group receiving standard therapy alone. Primary outcome measures were efficacy in preventing DCI.

Results: 107 subjects were allocated to the control (n=79) or study (n=28) groups. Incidence of DCI was 28% (n=22) and 18% (n=5), respectively (P=0.448). Subgroup analysis for HH grade 3+4(n=68) showed incidence of DCI of 24% (n=19) in the control group (n=50) and 7% (n=2) in the study group (n=18) (P=0.040). There were no LD-related complications.

Conclusions: This study could not draw a meaningful conclusion about the overall efficacy of LD on DCI reduction due to small sample size. However, there was a significant reduction of DCI by LD in the HH 3+4 subpopulation. Larger-scale studies are required to confirm our results.