Comparative investigation of different telemetric methods for measuring intracranial pressure: a prospective pilot study

Abstract

Objectives: Measurement of intracranial pressure (ICP) plays an important role in long-term monitoring and neuro-intensive treatment of patients with a cerebral shunt. Currently, only two complete telemetric implants with different technical features are available worldwide. This prospective pilot study aims to examine patients who had both probes implanted at overlapping times for clinical reasons and represents the first in vivo comparison of both measurement methods. Materials and methods: Patients with a primary subarachnoid hemorrhage or a spontaneous intracerebral hemorrhage with ventricular hemorrhage who had received a telemetric ICP probe (Raumedic® NEUROVENT®-P-tel) were included in the study. Conventional external ventricular drainages (EVD) and ventriculoperitoneal shunts with a telemetric ICP probe (Miethke Sensor Reservoir) were implanted in patients with hydrocephalus who required CSF (cerebrospinal fluid) drainage. Absolute ICP values from all systems were obtained. Due to the overlapping implantation time, parallel ICP measurements were performed via two devices simultaneously. ICP measurements via the sensor reservoir were repeated after 3 and 9 months. Differences between the absolute ICP values measured via the NEUROVENT®-P-tel probe, the Miethke sensor reservoir®, and the EVD were analyzed. Results: Seventeen patients were included in the present study between 2016 and 2018. 63% of all patients were male. In 11 patients the ICP measurements were followed up with both devices for 3 months. ICP measurements of the sensor reservoir showed corresponding trends in 9 cases compared to ICP measurement via the telemetry probe or EVD. Difference in absolute ICP values ranged between 14.5 mmHg and 0.0 mmHg. The average difference of the absolute ICP values in 8 cases was ≤ 3.5 mmHg. Conclusion: ICP measurements with both systems continuously showed synchronous absolute ICP values, however absolute values of ICP measurement with the different systems did not match.