gms | German Medical Science

60th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Benelux countries and Bulgaria

German Society of Neurosurgery (DGNC)

24 - 27 May 2009, Münster

Telemetric measurement of intracranial pressure (ICP): first experience of an experimental long-term in vivo study (365 days)

Meeting Abstract

  • B. Orakcioglu - Neurochirurgische Klinik, Universitätsklinikum Heidelberg
  • A. Aschoff - Neurochirurgische Klinik, Universitätsklinikum Heidelberg
  • O. Sakowitz - Neurochirurgische Klinik, Universitätsklinikum Heidelberg
  • C. Beynon - Neurochirurgische Klinik, Universitätsklinikum Heidelberg
  • J. Neumann - Neurochirurgische Klinik, Universitätsklinikum Heidelberg
  • R. Eymann - Neurochirurgische Klinik, Universitätskliniken des Saarlandes, Homburg/Saar
  • M. Kiefer - Neurochirurgische Klinik, Universitätskliniken des Saarlandes, Homburg/Saar
  • A. Unterberg - Neurochirurgische Klinik, Universitätsklinikum Heidelberg

Deutsche Gesellschaft für Neurochirurgie. 60. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit den Benelux-Ländern und Bulgarien. Münster, 24.-27.05.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. DocMO.12-08

DOI: 10.3205/09dgnc087, URN: urn:nbn:de:0183-09dgnc0876

Published: May 20, 2009

© 2009 Orakcioglu et al.
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Outline

Text

Objective: To test two new telemetric intracranial pressure (ICP) probes (NEUROVENT®-P-tel, NEUROVENT®-S-tel) within 365 days in a swine model. The goal was to correlate the new probes intraoperatively to parenchymal ICP-probes and study reliability, drift and infection rate (study ongoing at present). The experimental setup, new telemetric technology and preliminary data will be presented.

Methods: We implanted a right parietal (parenchymal) and left parietal (subdural) telemetric ICP-probe in 14 Göttingen mini-pigs under general anaesthesia. Through the left parietal burrhole a parenchymal ICP-probe (Neurovent®-ICP) was introduced. Intraoperatively, the head position was changed to provoke ICP changes every 10 minutes. The telemetric probes were left in situ and finally the ICP probe was removed. Every month the telemetric probes were checked for function and drift. In cases of doubtful readings, the probes were explanted and technological analysis was performed. Intraoperative measurements were repeated Iat 4 monthly intervals. We correlated mean diffenrences of each telemetric probe to the conventional ICP measurement and Bland-Altman plots were generated for statistical analysis.

Results: We present first data containing intraoperative measurements after implantation and at the 4-month follow-up. Intraoperatively, a mean difference of 2.4±1.2 mmHg (NEUROVENT®-P-tel) and 1.1±0.8 mmHg (NEUROVENT®-S-tel) was seen. The Bland-Altman plot demonstrates good correlation of the telemetric probes compared to the conventional ICP-probes. Intracranial pressure waveform analysis can easily be performed as ICP is measured 5x/second (5 Hz). Rate of infections within 4 months was 0%. After 60 days 4 of 28 telemetric probes were explanted due to signal loss. Technical analysis revealed fragile parts in the signal ASIC-unit that were modified afterwards.

Conclusions: We present a new telemetric technology that was experimentally compared to a parenchymal ICP-probe. We provide data that the new telemetric probes will reliably measure ICP. However, early during the study mechanically fragile parts were identified and were modified. This stand-alone ICP tool will allow permanent monitoring of ICP in hydrocephalus patients. Further continuation of our study will demonstrate whetherthis system warrants acceptable long-term reliability.