# Prospective Trial of Cerebrospinal Fluid Filtration After Aneurysmal Subarachnoid Hemorrhage via Lumbar Catheter Extension (PILLAR-XT)

## TL;DR

This study tested a new method to filter blood from cerebrospinal fluid in patients with brain aneurysm bleeding, showing it can safely and effectively remove blood products more quickly than standard care.

## Contribution

A novel closed-loop filtration system for removing blood from cerebrospinal fluid after aneurysmal subarachnoid hemorrhage is introduced and evaluated for safety and efficacy.

## Key findings

- The filtration system significantly reduced red blood cells and protein in cerebrospinal fluid compared to standard care.
- Intracranial blood levels decreased by 65% as measured by the Hijdra Sum Score.
- Adverse events were mild or moderate and resolved without lasting effects.

## Abstract

There is a growing consensus that blood in the cerebrospinal fluid (CSF) is deleterious to outcomes in patients with aneurysmal subarachnoid hemorrhage. The extracorporeal filtration of subarachnoid hemorrhage via spinal catheter extension study evaluated the safety, tolerability, and filtration curve of blood and its lysis products from hemorrhagic CSF using the Neurapheresis CSF Management System.

After aneurysm repair, a dual-lumen intrathecal catheter was inserted into the study participant’s spinal canal. CSF was extracorporeally filtered for up to 72 h, removing blood products from the lumbar cistern, and reintroducing filtered CSF to the thoracic subarachnoid space. Neurological examinations were performed every 2 h, computed tomography scans were captured five times, and CSF samples were evaluated for cell counts every 8 h. Clinical follow-up evaluations were conducted 2 and 30 days after treatment.

Twenty-seven of 29 study participants (93%) had a catheter successfully inserted. The median rate of waste removal was 5.7 mL/hr (interquartile range 3.9–8.8), and the median CSF filtration duration was 37:00 h (interquartile range 24:03–38:52). CSF red blood cell (mean reduction of 86%) and protein cell counts (mean reduction of 82%) decreased much faster in Neurapheresis system–treated participants compared with published data from standard-of-care patients with aneurysmal subarachnoid hemorrhage. From study participant screening through catheter removal, intracranial blood (evaluated via Hijdra Sum Score) decreased by 65%. In four study participants, there were a total of five adverse events, among whom one was determined per protocol to be a serious adverse event. All five events were mild or moderate severity and resolved with no clinical sequelae.

The Extracorporeal Filtration of Subarachnoid Hemorrhage Via Spinal Catheter Extension study demonstrated the potential to significantly accelerate intracranial blood elimination based on imaging (Hijdra Sum Score) and CSF red blood cell and protein reduction measures via a closed-loop filtration system.