Novel method for dynamic control of intracranial pressure

Area of Science:

• Biomedical Engineering
• Neurosurgery
• Physiology

Background:

• Intracranial pressure (ICP) pulsations are traditionally viewed as passive consequences of blood flow pulsatility.
• Investigating active modulation of ICP pulsations could reveal new insights into blood and cerebrospinal fluid (CSF) dynamics.
• Developing methods to actively alter ICP pulsations may offer novel therapeutic strategies for low blood flow conditions and CSF management.

Purpose of the Study:

• To introduce and evaluate a novel method and device for actively altering the intracranial pressure (ICP) waveform.
• To assess the feasibility and safety of using cardiac-gated volume changes to modify ICP pulsations.
• To explore the potential of this technique for studying ICP pulsatility's role in intracranial hemodynamics and for therapeutic applications.

Main Methods:

• A novel device, 'Cadence,' featuring a small intracranial balloon connected to a programmable pump triggered by R-wave detection was developed.
• The device was implanted in the epidural space of 19 canines, programmed to cyclically inflate/deflate with the cardiac cycle.
• ICP and cerebral blood flow were measured, analyzing effects of variable balloon inflation delay, phase, and volume.

Main Results:

• The Cadence device successfully modified the ICP waveform, enabling waveform flattening, amplitude increase, or phase shifting.
• Significant alterations in systolic ICP pulse amplitude were achieved (up to 1200% increase or -1600% decrease) in a dose-dependent manner.
• No significant deleterious effects on mean ICP, systemic pressure, or cardiac rate were observed during the study period.

Conclusions:

• The cardiac-gated, volume-oscillating balloon device (Cadence) can effectively modify ICP pulsations without causing adverse physiological effects.
• This technique provides a platform for investigating the functional role of ICP pulsatility in intracranial hydrodynamics.
• The Cadence system presents a potential therapeutic avenue for managing acute/chronic low blood flow states and conditions requiring CSF clearance/delivery augmentation.